| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Amelie Delaunay | 4675 | 55.38% | 7 | 33.33% |
| Cezary Gapinski | 3745 | 44.37% | 9 | 42.86% |
| Fabien Dessenne | 15 | 0.18% | 1 | 4.76% |
| Colin Ian King | 3 | 0.04% | 1 | 4.76% |
| Philipp Zabel | 1 | 0.01% | 1 | 4.76% |
| Christos Gkekas | 1 | 0.01% | 1 | 4.76% |
| Alexey Khoroshilov | 1 | 0.01% | 1 | 4.76% |
| Total | 8441 | 21 |
// SPDX-License-Identifier: GPL-2.0 // // STMicroelectronics STM32 SPI Controller driver (master mode only) // // Copyright (C) 2017, STMicroelectronics - All Rights Reserved // Author(s): Amelie Delaunay <amelie.delaunay@st.com> for STMicroelectronics. #include <linux/debugfs.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/gpio.h> #include <linux/interrupt.h> #include <linux/iopoll.h> #include <linux/module.h> #include <linux/of_platform.h> #include <linux/pm_runtime.h> #include <linux/reset.h> #include <linux/spi/spi.h> #define DRIVER_NAME "spi_stm32" /* STM32F4 SPI registers */ #define STM32F4_SPI_CR1 0x00 #define STM32F4_SPI_CR2 0x04 #define STM32F4_SPI_SR 0x08 #define STM32F4_SPI_DR 0x0C #define STM32F4_SPI_I2SCFGR 0x1C /* STM32F4_SPI_CR1 bit fields */ #define STM32F4_SPI_CR1_CPHA BIT(0) #define STM32F4_SPI_CR1_CPOL BIT(1) #define STM32F4_SPI_CR1_MSTR BIT(2) #define STM32F4_SPI_CR1_BR_SHIFT 3 #define STM32F4_SPI_CR1_BR GENMASK(5, 3) #define STM32F4_SPI_CR1_SPE BIT(6) #define STM32F4_SPI_CR1_LSBFRST BIT(7) #define STM32F4_SPI_CR1_SSI BIT(8) #define STM32F4_SPI_CR1_SSM BIT(9) #define STM32F4_SPI_CR1_RXONLY BIT(10) #define STM32F4_SPI_CR1_DFF BIT(11) #define STM32F4_SPI_CR1_CRCNEXT BIT(12) #define STM32F4_SPI_CR1_CRCEN BIT(13) #define STM32F4_SPI_CR1_BIDIOE BIT(14) #define STM32F4_SPI_CR1_BIDIMODE BIT(15) #define STM32F4_SPI_CR1_BR_MIN 0 #define STM32F4_SPI_CR1_BR_MAX (GENMASK(5, 3) >> 3) /* STM32F4_SPI_CR2 bit fields */ #define STM32F4_SPI_CR2_RXDMAEN BIT(0) #define STM32F4_SPI_CR2_TXDMAEN BIT(1) #define STM32F4_SPI_CR2_SSOE BIT(2) #define STM32F4_SPI_CR2_FRF BIT(4) #define STM32F4_SPI_CR2_ERRIE BIT(5) #define STM32F4_SPI_CR2_RXNEIE BIT(6) #define STM32F4_SPI_CR2_TXEIE BIT(7) /* STM32F4_SPI_SR bit fields */ #define STM32F4_SPI_SR_RXNE BIT(0) #define STM32F4_SPI_SR_TXE BIT(1) #define STM32F4_SPI_SR_CHSIDE BIT(2) #define STM32F4_SPI_SR_UDR BIT(3) #define STM32F4_SPI_SR_CRCERR BIT(4) #define STM32F4_SPI_SR_MODF BIT(5) #define STM32F4_SPI_SR_OVR BIT(6) #define STM32F4_SPI_SR_BSY BIT(7) #define STM32F4_SPI_SR_FRE BIT(8) /* STM32F4_SPI_I2SCFGR bit fields */ #define STM32F4_SPI_I2SCFGR_I2SMOD BIT(11) /* STM32F4 SPI Baud Rate min/max divisor */ #define STM32F4_SPI_BR_DIV_MIN (2 << STM32F4_SPI_CR1_BR_MIN) #define STM32F4_SPI_BR_DIV_MAX (2 << STM32F4_SPI_CR1_BR_MAX) /* STM32H7 SPI registers */ #define STM32H7_SPI_CR1 0x00 #define STM32H7_SPI_CR2 0x04 #define STM32H7_SPI_CFG1 0x08 #define STM32H7_SPI_CFG2 0x0C #define STM32H7_SPI_IER 0x10 #define STM32H7_SPI_SR 0x14 #define STM32H7_SPI_IFCR 0x18 #define STM32H7_SPI_TXDR 0x20 #define STM32H7_SPI_RXDR 0x30 #define STM32H7_SPI_I2SCFGR 0x50 /* STM32H7_SPI_CR1 bit fields */ #define STM32H7_SPI_CR1_SPE BIT(0) #define STM32H7_SPI_CR1_MASRX BIT(8) #define STM32H7_SPI_CR1_CSTART BIT(9) #define STM32H7_SPI_CR1_CSUSP BIT(10) #define STM32H7_SPI_CR1_HDDIR BIT(11) #define STM32H7_SPI_CR1_SSI BIT(12) /* STM32H7_SPI_CR2 bit fields */ #define STM32H7_SPI_CR2_TSIZE_SHIFT 0 #define STM32H7_SPI_CR2_TSIZE GENMASK(15, 0) /* STM32H7_SPI_CFG1 bit fields */ #define STM32H7_SPI_CFG1_DSIZE_SHIFT 0 #define STM32H7_SPI_CFG1_DSIZE GENMASK(4, 0) #define STM32H7_SPI_CFG1_FTHLV_SHIFT 5 #define STM32H7_SPI_CFG1_FTHLV GENMASK(8, 5) #define STM32H7_SPI_CFG1_RXDMAEN BIT(14) #define STM32H7_SPI_CFG1_TXDMAEN BIT(15) #define STM32H7_SPI_CFG1_MBR_SHIFT 28 #define STM32H7_SPI_CFG1_MBR GENMASK(30, 28) #define STM32H7_SPI_CFG1_MBR_MIN 0 #define STM32H7_SPI_CFG1_MBR_MAX (GENMASK(30, 28) >> 28) /* STM32H7_SPI_CFG2 bit fields */ #define STM32H7_SPI_CFG2_MIDI_SHIFT 4 #define STM32H7_SPI_CFG2_MIDI GENMASK(7, 4) #define STM32H7_SPI_CFG2_COMM_SHIFT 17 #define STM32H7_SPI_CFG2_COMM GENMASK(18, 17) #define STM32H7_SPI_CFG2_SP_SHIFT 19 #define STM32H7_SPI_CFG2_SP GENMASK(21, 19) #define STM32H7_SPI_CFG2_MASTER BIT(22) #define STM32H7_SPI_CFG2_LSBFRST BIT(23) #define STM32H7_SPI_CFG2_CPHA BIT(24) #define STM32H7_SPI_CFG2_CPOL BIT(25) #define STM32H7_SPI_CFG2_SSM BIT(26) #define STM32H7_SPI_CFG2_AFCNTR BIT(31) /* STM32H7_SPI_IER bit fields */ #define STM32H7_SPI_IER_RXPIE BIT(0) #define STM32H7_SPI_IER_TXPIE BIT(1) #define STM32H7_SPI_IER_DXPIE BIT(2) #define STM32H7_SPI_IER_EOTIE BIT(3) #define STM32H7_SPI_IER_TXTFIE BIT(4) #define STM32H7_SPI_IER_OVRIE BIT(6) #define STM32H7_SPI_IER_MODFIE BIT(9) #define STM32H7_SPI_IER_ALL GENMASK(10, 0) /* STM32H7_SPI_SR bit fields */ #define STM32H7_SPI_SR_RXP BIT(0) #define STM32H7_SPI_SR_TXP BIT(1) #define STM32H7_SPI_SR_EOT BIT(3) #define STM32H7_SPI_SR_OVR BIT(6) #define STM32H7_SPI_SR_MODF BIT(9) #define STM32H7_SPI_SR_SUSP BIT(11) #define STM32H7_SPI_SR_RXPLVL_SHIFT 13 #define STM32H7_SPI_SR_RXPLVL GENMASK(14, 13) #define STM32H7_SPI_SR_RXWNE BIT(15) /* STM32H7_SPI_IFCR bit fields */ #define STM32H7_SPI_IFCR_ALL GENMASK(11, 3) /* STM32H7_SPI_I2SCFGR bit fields */ #define STM32H7_SPI_I2SCFGR_I2SMOD BIT(0) /* STM32H7 SPI Master Baud Rate min/max divisor */ #define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN) #define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX) /* STM32H7 SPI Communication mode */ #define STM32H7_SPI_FULL_DUPLEX 0 #define STM32H7_SPI_SIMPLEX_TX 1 #define STM32H7_SPI_SIMPLEX_RX 2 #define STM32H7_SPI_HALF_DUPLEX 3 /* SPI Communication type */ #define SPI_FULL_DUPLEX 0 #define SPI_SIMPLEX_TX 1 #define SPI_SIMPLEX_RX 2 #define SPI_3WIRE_TX 3 #define SPI_3WIRE_RX 4 #define SPI_1HZ_NS 1000000000 /* * use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers * without fifo buffers. */ #define SPI_DMA_MIN_BYTES 16 /** * stm32_spi_reg - stm32 SPI register & bitfield desc * @reg: register offset * @mask: bitfield mask * @shift: left shift */ struct stm32_spi_reg { int reg; int mask; int shift; }; /** * stm32_spi_regspec - stm32 registers definition, compatible dependent data * en: enable register and SPI enable bit * dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit * dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit * cpol: clock polarity register and polarity bit * cpha: clock phase register and phase bit * lsb_first: LSB transmitted first register and bit * br: baud rate register and bitfields * rx: SPI RX data register * tx: SPI TX data register */ struct stm32_spi_regspec { const struct stm32_spi_reg en; const struct stm32_spi_reg dma_rx_en; const struct stm32_spi_reg dma_tx_en; const struct stm32_spi_reg cpol; const struct stm32_spi_reg cpha; const struct stm32_spi_reg lsb_first; const struct stm32_spi_reg br; const struct stm32_spi_reg rx; const struct stm32_spi_reg tx; }; struct stm32_spi; /** * stm32_spi_cfg - stm32 compatible configuration data * @regs: registers descriptions * @get_fifo_size: routine to get fifo size * @get_bpw_mask: routine to get bits per word mask * @disable: routine to disable controller * @config: routine to configure controller as SPI Master * @set_bpw: routine to configure registers to for bits per word * @set_mode: routine to configure registers to desired mode * @set_data_idleness: optional routine to configure registers to desired idle * time between frames (if driver has this functionality) * set_number_of_data: optional routine to configure registers to desired * number of data (if driver has this functionality) * @can_dma: routine to determine if the transfer is eligible for DMA use * @transfer_one_dma_start: routine to start transfer a single spi_transfer * using DMA * @dma_rx cb: routine to call after DMA RX channel operation is complete * @dma_tx cb: routine to call after DMA TX channel operation is complete * @transfer_one_irq: routine to configure interrupts for driver * @irq_handler_event: Interrupt handler for SPI controller events * @irq_handler_thread: thread of interrupt handler for SPI controller * @baud_rate_div_min: minimum baud rate divisor * @baud_rate_div_max: maximum baud rate divisor * @has_fifo: boolean to know if fifo is used for driver * @has_startbit: boolean to know if start bit is used to start transfer */ struct stm32_spi_cfg { const struct stm32_spi_regspec *regs; int (*get_fifo_size)(struct stm32_spi *spi); int (*get_bpw_mask)(struct stm32_spi *spi); void (*disable)(struct stm32_spi *spi); int (*config)(struct stm32_spi *spi); void (*set_bpw)(struct stm32_spi *spi); int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type); void (*set_data_idleness)(struct stm32_spi *spi, u32 length); int (*set_number_of_data)(struct stm32_spi *spi, u32 length); void (*transfer_one_dma_start)(struct stm32_spi *spi); void (*dma_rx_cb)(void *data); void (*dma_tx_cb)(void *data); int (*transfer_one_irq)(struct stm32_spi *spi); irqreturn_t (*irq_handler_event)(int irq, void *dev_id); irqreturn_t (*irq_handler_thread)(int irq, void *dev_id); unsigned int baud_rate_div_min; unsigned int baud_rate_div_max; bool has_fifo; }; /** * struct stm32_spi - private data of the SPI controller * @dev: driver model representation of the controller * @master: controller master interface * @cfg: compatible configuration data * @base: virtual memory area * @clk: hw kernel clock feeding the SPI clock generator * @clk_rate: rate of the hw kernel clock feeding the SPI clock generator * @rst: SPI controller reset line * @lock: prevent I/O concurrent access * @irq: SPI controller interrupt line * @fifo_size: size of the embedded fifo in bytes * @cur_midi: master inter-data idleness in ns * @cur_speed: speed configured in Hz * @cur_bpw: number of bits in a single SPI data frame * @cur_fthlv: fifo threshold level (data frames in a single data packet) * @cur_comm: SPI communication mode * @cur_xferlen: current transfer length in bytes * @cur_usedma: boolean to know if dma is used in current transfer * @tx_buf: data to be written, or NULL * @rx_buf: data to be read, or NULL * @tx_len: number of data to be written in bytes * @rx_len: number of data to be read in bytes * @dma_tx: dma channel for TX transfer * @dma_rx: dma channel for RX transfer * @phys_addr: SPI registers physical base address */ struct stm32_spi { struct device *dev; struct spi_master *master; const struct stm32_spi_cfg *cfg; void __iomem *base; struct clk *clk; u32 clk_rate; struct reset_control *rst; spinlock_t lock; /* prevent I/O concurrent access */ int irq; unsigned int fifo_size; unsigned int cur_midi; unsigned int cur_speed; unsigned int cur_bpw; unsigned int cur_fthlv; unsigned int cur_comm; unsigned int cur_xferlen; bool cur_usedma; const void *tx_buf; void *rx_buf; int tx_len; int rx_len; struct dma_chan *dma_tx; struct dma_chan *dma_rx; dma_addr_t phys_addr; }; static const struct stm32_spi_regspec stm32f4_spi_regspec = { .en = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE }, .dma_rx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_RXDMAEN }, .dma_tx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN }, .cpol = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPOL }, .cpha = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPHA }, .lsb_first = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_LSBFRST }, .br = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_BR, STM32F4_SPI_CR1_BR_SHIFT }, .rx = { STM32F4_SPI_DR }, .tx = { STM32F4_SPI_DR }, }; static const struct stm32_spi_regspec stm32h7_spi_regspec = { /* SPI data transfer is enabled but spi_ker_ck is idle. * CFG1 and CFG2 registers are write protected when SPE is enabled. */ .en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE }, .dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN }, .dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN }, .cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL }, .cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA }, .lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST }, .br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR, STM32H7_SPI_CFG1_MBR_SHIFT }, .rx = { STM32H7_SPI_RXDR }, .tx = { STM32H7_SPI_TXDR }, }; static inline void stm32_spi_set_bits(struct stm32_spi *spi, u32 offset, u32 bits) { writel_relaxed(readl_relaxed(spi->base + offset) | bits, spi->base + offset); } static inline void stm32_spi_clr_bits(struct stm32_spi *spi, u32 offset, u32 bits) { writel_relaxed(readl_relaxed(spi->base + offset) & ~bits, spi->base + offset); } /** * stm32h7_spi_get_fifo_size - Return fifo size * @spi: pointer to the spi controller data structure */ static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi) { unsigned long flags; u32 count = 0; spin_lock_irqsave(&spi->lock, flags); stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP) writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR); stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); spin_unlock_irqrestore(&spi->lock, flags); dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count); return count; } /** * stm32f4_spi_get_bpw_mask - Return bits per word mask * @spi: pointer to the spi controller data structure */ static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi) { dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n"); return SPI_BPW_MASK(8) | SPI_BPW_MASK(16); } /** * stm32h7_spi_get_bpw_mask - Return bits per word mask * @spi: pointer to the spi controller data structure */ static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi) { unsigned long flags; u32 cfg1, max_bpw; spin_lock_irqsave(&spi->lock, flags); /* * The most significant bit at DSIZE bit field is reserved when the * maximum data size of periperal instances is limited to 16-bit */ stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE); cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1); max_bpw = (cfg1 & STM32H7_SPI_CFG1_DSIZE) >> STM32H7_SPI_CFG1_DSIZE_SHIFT; max_bpw += 1; spin_unlock_irqrestore(&spi->lock, flags); dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw); return SPI_BPW_RANGE_MASK(4, max_bpw); } /** * stm32_spi_prepare_mbr - Determine baud rate divisor value * @spi: pointer to the spi controller data structure * @speed_hz: requested speed * @min_div: minimum baud rate divisor * @max_div: maximum baud rate divisor * * Return baud rate divisor value in case of success or -EINVAL */ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz, u32 min_div, u32 max_div) { u32 div, mbrdiv; div = DIV_ROUND_UP(spi->clk_rate, speed_hz); /* * SPI framework set xfer->speed_hz to master->max_speed_hz if * xfer->speed_hz is greater than master->max_speed_hz, and it returns * an error when xfer->speed_hz is lower than master->min_speed_hz, so * no need to check it there. * However, we need to ensure the following calculations. */ if ((div < min_div) || (div > max_div)) return -EINVAL; /* Determine the first power of 2 greater than or equal to div */ if (div & (div - 1)) mbrdiv = fls(div); else mbrdiv = fls(div) - 1; spi->cur_speed = spi->clk_rate / (1 << mbrdiv); return mbrdiv - 1; } /** * stm32h7_spi_prepare_fthlv - Determine FIFO threshold level * @spi: pointer to the spi controller data structure */ static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi) { u32 fthlv, half_fifo; /* data packet should not exceed 1/2 of fifo space */ half_fifo = (spi->fifo_size / 2); if (spi->cur_bpw <= 8) fthlv = half_fifo; else if (spi->cur_bpw <= 16) fthlv = half_fifo / 2; else fthlv = half_fifo / 4; /* align packet size with data registers access */ if (spi->cur_bpw > 8) fthlv -= (fthlv % 2); /* multiple of 2 */ else fthlv -= (fthlv % 4); /* multiple of 4 */ return fthlv; } /** * stm32f4_spi_write_tx - Write bytes to Transmit Data Register * @spi: pointer to the spi controller data structure * * Read from tx_buf depends on remaining bytes to avoid to read beyond * tx_buf end. */ static void stm32f4_spi_write_tx(struct stm32_spi *spi) { if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) & STM32F4_SPI_SR_TXE)) { u32 offs = spi->cur_xferlen - spi->tx_len; if (spi->cur_bpw == 16) { const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs); writew_relaxed(*tx_buf16, spi->base + STM32F4_SPI_DR); spi->tx_len -= sizeof(u16); } else { const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs); writeb_relaxed(*tx_buf8, spi->base + STM32F4_SPI_DR); spi->tx_len -= sizeof(u8); } } dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len); } /** * stm32h7_spi_write_txfifo - Write bytes in Transmit Data Register * @spi: pointer to the spi controller data structure * * Read from tx_buf depends on remaining bytes to avoid to read beyond * tx_buf end. */ static void stm32h7_spi_write_txfifo(struct stm32_spi *spi) { while ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP)) { u32 offs = spi->cur_xferlen - spi->tx_len; if (spi->tx_len >= sizeof(u32)) { const u32 *tx_buf32 = (const u32 *)(spi->tx_buf + offs); writel_relaxed(*tx_buf32, spi->base + STM32H7_SPI_TXDR); spi->tx_len -= sizeof(u32); } else if (spi->tx_len >= sizeof(u16)) { const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs); writew_relaxed(*tx_buf16, spi->base + STM32H7_SPI_TXDR); spi->tx_len -= sizeof(u16); } else { const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs); writeb_relaxed(*tx_buf8, spi->base + STM32H7_SPI_TXDR); spi->tx_len -= sizeof(u8); } } dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len); } /** * stm32f4_spi_read_rx - Read bytes from Receive Data Register * @spi: pointer to the spi controller data structure * * Write in rx_buf depends on remaining bytes to avoid to write beyond * rx_buf end. */ static void stm32f4_spi_read_rx(struct stm32_spi *spi) { if ((spi->rx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) & STM32F4_SPI_SR_RXNE)) { u32 offs = spi->cur_xferlen - spi->rx_len; if (spi->cur_bpw == 16) { u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs); *rx_buf16 = readw_relaxed(spi->base + STM32F4_SPI_DR); spi->rx_len -= sizeof(u16); } else { u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs); *rx_buf8 = readb_relaxed(spi->base + STM32F4_SPI_DR); spi->rx_len -= sizeof(u8); } } dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len); } /** * stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register * @spi: pointer to the spi controller data structure * * Write in rx_buf depends on remaining bytes to avoid to write beyond * rx_buf end. */ static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush) { u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR); u32 rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >> STM32H7_SPI_SR_RXPLVL_SHIFT; while ((spi->rx_len > 0) && ((sr & STM32H7_SPI_SR_RXP) || (flush && ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) { u32 offs = spi->cur_xferlen - spi->rx_len; if ((spi->rx_len >= sizeof(u32)) || (flush && (sr & STM32H7_SPI_SR_RXWNE))) { u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs); *rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR); spi->rx_len -= sizeof(u32); } else if ((spi->rx_len >= sizeof(u16)) || (flush && (rxplvl >= 2 || spi->cur_bpw > 8))) { u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs); *rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR); spi->rx_len -= sizeof(u16); } else { u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs); *rx_buf8 = readb_relaxed(spi->base + STM32H7_SPI_RXDR); spi->rx_len -= sizeof(u8); } sr = readl_relaxed(spi->base + STM32H7_SPI_SR); rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >> STM32H7_SPI_SR_RXPLVL_SHIFT; } dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__, flush ? "(flush)" : "", spi->rx_len); } /** * stm32_spi_enable - Enable SPI controller * @spi: pointer to the spi controller data structure */ static void stm32_spi_enable(struct stm32_spi *spi) { dev_dbg(spi->dev, "enable controller\n"); stm32_spi_set_bits(spi, spi->cfg->regs->en.reg, spi->cfg->regs->en.mask); } /** * stm32f4_spi_disable - Disable SPI controller * @spi: pointer to the spi controller data structure */ static void stm32f4_spi_disable(struct stm32_spi *spi) { unsigned long flags; u32 sr; dev_dbg(spi->dev, "disable controller\n"); spin_lock_irqsave(&spi->lock, flags); if (!(readl_relaxed(spi->base + STM32F4_SPI_CR1) & STM32F4_SPI_CR1_SPE)) { spin_unlock_irqrestore(&spi->lock, flags); return; } /* Disable interrupts */ stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXEIE | STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE); /* Wait until BSY = 0 */ if (readl_relaxed_poll_timeout_atomic(spi->base + STM32F4_SPI_SR, sr, !(sr & STM32F4_SPI_SR_BSY), 10, 100000) < 0) { dev_warn(spi->dev, "disabling condition timeout\n"); } if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_all(spi->dma_tx); if (spi->cur_usedma && spi->dma_rx) dmaengine_terminate_all(spi->dma_rx); stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE); stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN | STM32F4_SPI_CR2_RXDMAEN); /* Sequence to clear OVR flag */ readl_relaxed(spi->base + STM32F4_SPI_DR); readl_relaxed(spi->base + STM32F4_SPI_SR); spin_unlock_irqrestore(&spi->lock, flags); } /** * stm32h7_spi_disable - Disable SPI controller * @spi: pointer to the spi controller data structure * * RX-Fifo is flushed when SPI controller is disabled. To prevent any data * loss, use stm32h7_spi_read_rxfifo(flush) to read the remaining bytes in * RX-Fifo. * Normally, if TSIZE has been configured, we should relax the hardware at the * reception of the EOT interrupt. But in case of error, EOT will not be * raised. So the subsystem unprepare_message call allows us to properly * complete the transfer from an hardware point of view. */ static void stm32h7_spi_disable(struct stm32_spi *spi) { unsigned long flags; u32 cr1, sr; dev_dbg(spi->dev, "disable controller\n"); spin_lock_irqsave(&spi->lock, flags); cr1 = readl_relaxed(spi->base + STM32H7_SPI_CR1); if (!(cr1 & STM32H7_SPI_CR1_SPE)) { spin_unlock_irqrestore(&spi->lock, flags); return; } /* Wait on EOT or suspend the flow */ if (readl_relaxed_poll_timeout_atomic(spi->base + STM32H7_SPI_SR, sr, !(sr & STM32H7_SPI_SR_EOT), 10, 100000) < 0) { if (cr1 & STM32H7_SPI_CR1_CSTART) { writel_relaxed(cr1 | STM32H7_SPI_CR1_CSUSP, spi->base + STM32H7_SPI_CR1); if (readl_relaxed_poll_timeout_atomic( spi->base + STM32H7_SPI_SR, sr, !(sr & STM32H7_SPI_SR_SUSP), 10, 100000) < 0) dev_warn(spi->dev, "Suspend request timeout\n"); } } if (!spi->cur_usedma && spi->rx_buf && (spi->rx_len > 0)) stm32h7_spi_read_rxfifo(spi, true); if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_all(spi->dma_tx); if (spi->cur_usedma && spi->dma_rx) dmaengine_terminate_all(spi->dma_rx); stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); stm32_spi_clr_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN | STM32H7_SPI_CFG1_RXDMAEN); /* Disable interrupts and clear status flags */ writel_relaxed(0, spi->base + STM32H7_SPI_IER); writel_relaxed(STM32H7_SPI_IFCR_ALL, spi->base + STM32H7_SPI_IFCR); spin_unlock_irqrestore(&spi->lock, flags); } /** * stm32_spi_can_dma - Determine if the transfer is eligible for DMA use * * If driver has fifo and the current transfer size is greater than fifo size, * use DMA. Otherwise use DMA for transfer longer than defined DMA min bytes. */ static bool stm32_spi_can_dma(struct spi_master *master, struct spi_device *spi_dev, struct spi_transfer *transfer) { unsigned int dma_size; struct stm32_spi *spi = spi_master_get_devdata(master); if (spi->cfg->has_fifo) dma_size = spi->fifo_size; else dma_size = SPI_DMA_MIN_BYTES; dev_dbg(spi->dev, "%s: %s\n", __func__, (transfer->len > dma_size) ? "true" : "false"); return (transfer->len > dma_size); } /** * stm32f4_spi_irq_event - Interrupt handler for SPI controller events * @irq: interrupt line * @dev_id: SPI controller master interface */ static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id) { struct spi_master *master = dev_id; struct stm32_spi *spi = spi_master_get_devdata(master); u32 sr, mask = 0; unsigned long flags; bool end = false; spin_lock_irqsave(&spi->lock, flags); sr = readl_relaxed(spi->base + STM32F4_SPI_SR); /* * BSY flag is not handled in interrupt but it is normal behavior when * this flag is set. */ sr &= ~STM32F4_SPI_SR_BSY; if (!spi->cur_usedma && (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)) { /* OVR flag shouldn't be handled for TX only mode */ sr &= ~STM32F4_SPI_SR_OVR | STM32F4_SPI_SR_RXNE; mask |= STM32F4_SPI_SR_TXE; } if (!spi->cur_usedma && spi->cur_comm == SPI_FULL_DUPLEX) { /* TXE flag is set and is handled when RXNE flag occurs */ sr &= ~STM32F4_SPI_SR_TXE; mask |= STM32F4_SPI_SR_RXNE | STM32F4_SPI_SR_OVR; } if (!(sr & mask)) { dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr); spin_unlock_irqrestore(&spi->lock, flags); return IRQ_NONE; } if (sr & STM32F4_SPI_SR_OVR) { dev_warn(spi->dev, "Overrun: received value discarded\n"); /* Sequence to clear OVR flag */ readl_relaxed(spi->base + STM32F4_SPI_DR); readl_relaxed(spi->base + STM32F4_SPI_SR); /* * If overrun is detected, it means that something went wrong, * so stop the current transfer. Transfer can wait for next * RXNE but DR is already read and end never happens. */ end = true; goto end_irq; } if (sr & STM32F4_SPI_SR_TXE) { if (spi->tx_buf) stm32f4_spi_write_tx(spi); if (spi->tx_len == 0) end = true; } if (sr & STM32F4_SPI_SR_RXNE) { stm32f4_spi_read_rx(spi); if (spi->rx_len == 0) end = true; else /* Load data for discontinuous mode */ stm32f4_spi_write_tx(spi); } end_irq: if (end) { /* Immediately disable interrupts to do not generate new one */ stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXEIE | STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE); spin_unlock_irqrestore(&spi->lock, flags); return IRQ_WAKE_THREAD; } spin_unlock_irqrestore(&spi->lock, flags); return IRQ_HANDLED; } /** * stm32f4_spi_irq_thread - Thread of interrupt handler for SPI controller * @irq: interrupt line * @dev_id: SPI controller master interface */ static irqreturn_t stm32f4_spi_irq_thread(int irq, void *dev_id) { struct spi_master *master = dev_id; struct stm32_spi *spi = spi_master_get_devdata(master); spi_finalize_current_transfer(master); stm32f4_spi_disable(spi); return IRQ_HANDLED; } /** * stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller * @irq: interrupt line * @dev_id: SPI controller master interface */ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) { struct spi_master *master = dev_id; struct stm32_spi *spi = spi_master_get_devdata(master); u32 sr, ier, mask; unsigned long flags; bool end = false; spin_lock_irqsave(&spi->lock, flags); sr = readl_relaxed(spi->base + STM32H7_SPI_SR); ier = readl_relaxed(spi->base + STM32H7_SPI_IER); mask = ier; /* EOTIE is triggered on EOT, SUSP and TXC events. */ mask |= STM32H7_SPI_SR_SUSP; /* * When TXTF is set, DXPIE and TXPIE are cleared. So in case of * Full-Duplex, need to poll RXP event to know if there are remaining * data, before disabling SPI. */ if (spi->rx_buf && !spi->cur_usedma) mask |= STM32H7_SPI_SR_RXP; if (!(sr & mask)) { dev_dbg(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n", sr, ier); spin_unlock_irqrestore(&spi->lock, flags); return IRQ_NONE; } if (sr & STM32H7_SPI_SR_SUSP) { dev_warn(spi->dev, "Communication suspended\n"); if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32h7_spi_read_rxfifo(spi, false); /* * If communication is suspended while using DMA, it means * that something went wrong, so stop the current transfer */ if (spi->cur_usedma) end = true; } if (sr & STM32H7_SPI_SR_MODF) { dev_warn(spi->dev, "Mode fault: transfer aborted\n"); end = true; } if (sr & STM32H7_SPI_SR_OVR) { dev_warn(spi->dev, "Overrun: received value discarded\n"); if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32h7_spi_read_rxfifo(spi, false); /* * If overrun is detected while using DMA, it means that * something went wrong, so stop the current transfer */ if (spi->cur_usedma) end = true; } if (sr & STM32H7_SPI_SR_EOT) { if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32h7_spi_read_rxfifo(spi, true); end = true; } if (sr & STM32H7_SPI_SR_TXP) if (!spi->cur_usedma && (spi->tx_buf && (spi->tx_len > 0))) stm32h7_spi_write_txfifo(spi); if (sr & STM32H7_SPI_SR_RXP) if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) stm32h7_spi_read_rxfifo(spi, false); writel_relaxed(mask, spi->base + STM32H7_SPI_IFCR); spin_unlock_irqrestore(&spi->lock, flags); if (end) { spi_finalize_current_transfer(master); stm32h7_spi_disable(spi); } return IRQ_HANDLED; } /** * stm32_spi_setup - setup device chip select */ static int stm32_spi_setup(struct spi_device *spi_dev) { int ret = 0; if (!gpio_is_valid(spi_dev->cs_gpio)) { dev_err(&spi_dev->dev, "%d is not a valid gpio\n", spi_dev->cs_gpio); return -EINVAL; } dev_dbg(&spi_dev->dev, "%s: set gpio%d output %s\n", __func__, spi_dev->cs_gpio, (spi_dev->mode & SPI_CS_HIGH) ? "low" : "high"); ret = gpio_direction_output(spi_dev->cs_gpio, !(spi_dev->mode & SPI_CS_HIGH)); return ret; } /** * stm32_spi_prepare_msg - set up the controller to transfer a single message */ static int stm32_spi_prepare_msg(struct spi_master *master, struct spi_message *msg) { struct stm32_spi *spi = spi_master_get_devdata(master); struct spi_device *spi_dev = msg->spi; struct device_node *np = spi_dev->dev.of_node; unsigned long flags; u32 clrb = 0, setb = 0; /* SPI slave device may need time between data frames */ spi->cur_midi = 0; if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi)) dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi); if (spi_dev->mode & SPI_CPOL) setb |= spi->cfg->regs->cpol.mask; else clrb |= spi->cfg->regs->cpol.mask; if (spi_dev->mode & SPI_CPHA) setb |= spi->cfg->regs->cpha.mask; else clrb |= spi->cfg->regs->cpha.mask; if (spi_dev->mode & SPI_LSB_FIRST) setb |= spi->cfg->regs->lsb_first.mask; else clrb |= spi->cfg->regs->lsb_first.mask; dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n", spi_dev->mode & SPI_CPOL, spi_dev->mode & SPI_CPHA, spi_dev->mode & SPI_LSB_FIRST, spi_dev->mode & SPI_CS_HIGH); spin_lock_irqsave(&spi->lock, flags); /* CPOL, CPHA and LSB FIRST bits have common register */ if (clrb || setb) writel_relaxed( (readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) & ~clrb) | setb, spi->base + spi->cfg->regs->cpol.reg); spin_unlock_irqrestore(&spi->lock, flags); return 0; } /** * stm32f4_spi_dma_tx_cb - dma callback * * DMA callback is called when the transfer is complete for DMA TX channel. */ static void stm32f4_spi_dma_tx_cb(void *data) { struct stm32_spi *spi = data; if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { spi_finalize_current_transfer(spi->master); stm32f4_spi_disable(spi); } } /** * stm32f4_spi_dma_rx_cb - dma callback * * DMA callback is called when the transfer is complete for DMA RX channel. */ static void stm32f4_spi_dma_rx_cb(void *data) { struct stm32_spi *spi = data; spi_finalize_current_transfer(spi->master); stm32f4_spi_disable(spi); } /** * stm32h7_spi_dma_cb - dma callback * * DMA callback is called when the transfer is complete or when an error * occurs. If the transfer is complete, EOT flag is raised. */ static void stm32h7_spi_dma_cb(void *data) { struct stm32_spi *spi = data; unsigned long flags; u32 sr; spin_lock_irqsave(&spi->lock, flags); sr = readl_relaxed(spi->base + STM32H7_SPI_SR); spin_unlock_irqrestore(&spi->lock, flags); if (!(sr & STM32H7_SPI_SR_EOT)) dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr); /* Now wait for EOT, or SUSP or OVR in case of error */ } /** * stm32_spi_dma_config - configure dma slave channel depending on current * transfer bits_per_word. */ static void stm32_spi_dma_config(struct stm32_spi *spi, struct dma_slave_config *dma_conf, enum dma_transfer_direction dir) { enum dma_slave_buswidth buswidth; u32 maxburst; if (spi->cur_bpw <= 8) buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; else if (spi->cur_bpw <= 16) buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; else buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; if (spi->cfg->has_fifo) { /* Valid for DMA Half or Full Fifo threshold */ if (spi->cur_fthlv == 2) maxburst = 1; else maxburst = spi->cur_fthlv; } else { maxburst = 1; } memset(dma_conf, 0, sizeof(struct dma_slave_config)); dma_conf->direction = dir; if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */ dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg; dma_conf->src_addr_width = buswidth; dma_conf->src_maxburst = maxburst; dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n", buswidth, maxburst); } else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */ dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg; dma_conf->dst_addr_width = buswidth; dma_conf->dst_maxburst = maxburst; dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n", buswidth, maxburst); } } /** * stm32f4_spi_transfer_one_irq - transfer a single spi_transfer using * interrupts * * It must returns 0 if the transfer is finished or 1 if the transfer is still * in progress. */ static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi) { unsigned long flags; u32 cr2 = 0; /* Enable the interrupts relative to the current communication mode */ if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { cr2 |= STM32F4_SPI_CR2_TXEIE; } else if (spi->cur_comm == SPI_FULL_DUPLEX) { /* In transmit-only mode, the OVR flag is set in the SR register * since the received data are never read. Therefore set OVR * interrupt only when rx buffer is available. */ cr2 |= STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE; } else { return -EINVAL; } spin_lock_irqsave(&spi->lock, flags); stm32_spi_set_bits(spi, STM32F4_SPI_CR2, cr2); stm32_spi_enable(spi); /* starting data transfer when buffer is loaded */ if (spi->tx_buf) stm32f4_spi_write_tx(spi); spin_unlock_irqrestore(&spi->lock, flags); return 1; } /** * stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using * interrupts * * It must returns 0 if the transfer is finished or 1 if the transfer is still * in progress. */ static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi) { unsigned long flags; u32 ier = 0; /* Enable the interrupts relative to the current communication mode */ if (spi->tx_buf && spi->rx_buf) /* Full Duplex */ ier |= STM32H7_SPI_IER_DXPIE; else if (spi->tx_buf) /* Half-Duplex TX dir or Simplex TX */ ier |= STM32H7_SPI_IER_TXPIE; else if (spi->rx_buf) /* Half-Duplex RX dir or Simplex RX */ ier |= STM32H7_SPI_IER_RXPIE; /* Enable the interrupts relative to the end of transfer */ ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE | STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE; spin_lock_irqsave(&spi->lock, flags); stm32_spi_enable(spi); /* Be sure to have data in fifo before starting data transfer */ if (spi->tx_buf) stm32h7_spi_write_txfifo(spi); stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART); writel_relaxed(ier, spi->base + STM32H7_SPI_IER); spin_unlock_irqrestore(&spi->lock, flags); return 1; } /** * stm32f4_spi_transfer_one_dma_start - Set SPI driver registers to start * transfer using DMA */ static void stm32f4_spi_transfer_one_dma_start(struct stm32_spi *spi) { /* In DMA mode end of transfer is handled by DMA TX or RX callback. */ if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX || spi->cur_comm == SPI_FULL_DUPLEX) { /* * In transmit-only mode, the OVR flag is set in the SR register * since the received data are never read. Therefore set OVR * interrupt only when rx buffer is available. */ stm32_spi_set_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_ERRIE); } stm32_spi_enable(spi); } /** * stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start * transfer using DMA */ static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi) { /* Enable the interrupts relative to the end of transfer */ stm32_spi_set_bits(spi, STM32H7_SPI_IER, STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE | STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE); stm32_spi_enable(spi); stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART); } /** * stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA * * It must returns 0 if the transfer is finished or 1 if the transfer is still * in progress. */ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi, struct spi_transfer *xfer) { struct dma_slave_config tx_dma_conf, rx_dma_conf; struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc; unsigned long flags; spin_lock_irqsave(&spi->lock, flags); rx_dma_desc = NULL; if (spi->rx_buf && spi->dma_rx) { stm32_spi_dma_config(spi, &rx_dma_conf, DMA_DEV_TO_MEM); dmaengine_slave_config(spi->dma_rx, &rx_dma_conf); /* Enable Rx DMA request */ stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg, spi->cfg->regs->dma_rx_en.mask); rx_dma_desc = dmaengine_prep_slave_sg( spi->dma_rx, xfer->rx_sg.sgl, xfer->rx_sg.nents, rx_dma_conf.direction, DMA_PREP_INTERRUPT); } tx_dma_desc = NULL; if (spi->tx_buf && spi->dma_tx) { stm32_spi_dma_config(spi, &tx_dma_conf, DMA_MEM_TO_DEV); dmaengine_slave_config(spi->dma_tx, &tx_dma_conf); tx_dma_desc = dmaengine_prep_slave_sg( spi->dma_tx, xfer->tx_sg.sgl, xfer->tx_sg.nents, tx_dma_conf.direction, DMA_PREP_INTERRUPT); } if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) || (spi->rx_buf && spi->dma_rx && !rx_dma_desc)) goto dma_desc_error; if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc)) goto dma_desc_error; if (rx_dma_desc) { rx_dma_desc->callback = spi->cfg->dma_rx_cb; rx_dma_desc->callback_param = spi; if (dma_submit_error(dmaengine_submit(rx_dma_desc))) { dev_err(spi->dev, "Rx DMA submit failed\n"); goto dma_desc_error; } /* Enable Rx DMA channel */ dma_async_issue_pending(spi->dma_rx); } if (tx_dma_desc) { if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { tx_dma_desc->callback = spi->cfg->dma_tx_cb; tx_dma_desc->callback_param = spi; } if (dma_submit_error(dmaengine_submit(tx_dma_desc))) { dev_err(spi->dev, "Tx DMA submit failed\n"); goto dma_submit_error; } /* Enable Tx DMA channel */ dma_async_issue_pending(spi->dma_tx); /* Enable Tx DMA request */ stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg, spi->cfg->regs->dma_tx_en.mask); } spi->cfg->transfer_one_dma_start(spi); spin_unlock_irqrestore(&spi->lock, flags); return 1; dma_submit_error: if (spi->dma_rx) dmaengine_terminate_all(spi->dma_rx); dma_desc_error: stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg, spi->cfg->regs->dma_rx_en.mask); spin_unlock_irqrestore(&spi->lock, flags); dev_info(spi->dev, "DMA issue: fall back to irq transfer\n"); spi->cur_usedma = false; return spi->cfg->transfer_one_irq(spi); } /** * stm32f4_spi_set_bpw - Configure bits per word * @spi: pointer to the spi controller data structure */ static void stm32f4_spi_set_bpw(struct stm32_spi *spi) { if (spi->cur_bpw == 16) stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF); else stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF); } /** * stm32h7_spi_set_bpw - configure bits per word * @spi: pointer to the spi controller data structure */ static void stm32h7_spi_set_bpw(struct stm32_spi *spi) { u32 bpw, fthlv; u32 cfg1_clrb = 0, cfg1_setb = 0; bpw = spi->cur_bpw - 1; cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE; cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) & STM32H7_SPI_CFG1_DSIZE; spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi); fthlv = spi->cur_fthlv - 1; cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV; cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) & STM32H7_SPI_CFG1_FTHLV; writel_relaxed( (readl_relaxed(spi->base + STM32H7_SPI_CFG1) & ~cfg1_clrb) | cfg1_setb, spi->base + STM32H7_SPI_CFG1); } /** * stm32_spi_set_mbr - Configure baud rate divisor in master mode * @spi: pointer to the spi controller data structure * @mbrdiv: baud rate divisor value */ static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv) { u32 clrb = 0, setb = 0; clrb |= spi->cfg->regs->br.mask; setb |= ((u32)mbrdiv << spi->cfg->regs->br.shift) & spi->cfg->regs->br.mask; writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) & ~clrb) | setb, spi->base + spi->cfg->regs->br.reg); } /** * stm32_spi_communication_type - return transfer communication type * @spi_dev: pointer to the spi device * transfer: pointer to spi transfer */ static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev, struct spi_transfer *transfer) { unsigned int type = SPI_FULL_DUPLEX; if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */ /* * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL * is forbidden and unvalidated by SPI subsystem so depending * on the valid buffer, we can determine the direction of the * transfer. */ if (!transfer->tx_buf) type = SPI_3WIRE_RX; else type = SPI_3WIRE_TX; } else { if (!transfer->tx_buf) type = SPI_SIMPLEX_RX; else if (!transfer->rx_buf) type = SPI_SIMPLEX_TX; } return type; } /** * stm32f4_spi_set_mode - configure communication mode * @spi: pointer to the spi controller data structure * @comm_type: type of communication to configure */ static int stm32f4_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) { if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) { stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_BIDIMODE | STM32F4_SPI_CR1_BIDIOE); } else if (comm_type == SPI_FULL_DUPLEX) { stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_BIDIMODE | STM32F4_SPI_CR1_BIDIOE); } else { return -EINVAL; } return 0; } /** * stm32h7_spi_set_mode - configure communication mode * @spi: pointer to the spi controller data structure * @comm_type: type of communication to configure */ static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) { u32 mode; u32 cfg2_clrb = 0, cfg2_setb = 0; if (comm_type == SPI_3WIRE_RX) { mode = STM32H7_SPI_HALF_DUPLEX; stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); } else if (comm_type == SPI_3WIRE_TX) { mode = STM32H7_SPI_HALF_DUPLEX; stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); } else if (comm_type == SPI_SIMPLEX_RX) { mode = STM32H7_SPI_SIMPLEX_RX; } else if (comm_type == SPI_SIMPLEX_TX) { mode = STM32H7_SPI_SIMPLEX_TX; } else { mode = STM32H7_SPI_FULL_DUPLEX; } cfg2_clrb |= STM32H7_SPI_CFG2_COMM; cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) & STM32H7_SPI_CFG2_COMM; writel_relaxed( (readl_relaxed(spi->base + STM32H7_SPI_CFG2) & ~cfg2_clrb) | cfg2_setb, spi->base + STM32H7_SPI_CFG2); return 0; } /** * stm32h7_spi_data_idleness - configure minimum time delay inserted between two * consecutive data frames in master mode * @spi: pointer to the spi controller data structure * @len: transfer len */ static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len) { u32 cfg2_clrb = 0, cfg2_setb = 0; cfg2_clrb |= STM32H7_SPI_CFG2_MIDI; if ((len > 1) && (spi->cur_midi > 0)) { u32 sck_period_ns = DIV_ROUND_UP(SPI_1HZ_NS, spi->cur_speed); u32 midi = min((u32)DIV_ROUND_UP(spi->cur_midi, sck_period_ns), (u32)STM32H7_SPI_CFG2_MIDI >> STM32H7_SPI_CFG2_MIDI_SHIFT); dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n", sck_period_ns, midi, midi * sck_period_ns); cfg2_setb |= (midi << STM32H7_SPI_CFG2_MIDI_SHIFT) & STM32H7_SPI_CFG2_MIDI; } writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) & ~cfg2_clrb) | cfg2_setb, spi->base + STM32H7_SPI_CFG2); } /** * stm32h7_spi_number_of_data - configure number of data at current transfer * @spi: pointer to the spi controller data structure * @len: transfer length */ static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words) { u32 cr2_clrb = 0, cr2_setb = 0; if (nb_words <= (STM32H7_SPI_CR2_TSIZE >> STM32H7_SPI_CR2_TSIZE_SHIFT)) { cr2_clrb |= STM32H7_SPI_CR2_TSIZE; cr2_setb = nb_words << STM32H7_SPI_CR2_TSIZE_SHIFT; writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CR2) & ~cr2_clrb) | cr2_setb, spi->base + STM32H7_SPI_CR2); } else { return -EMSGSIZE; } return 0; } /** * stm32_spi_transfer_one_setup - common setup to transfer a single * spi_transfer either using DMA or * interrupts. */ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, struct spi_device *spi_dev, struct spi_transfer *transfer) { unsigned long flags; unsigned int comm_type; int nb_words, ret = 0; spin_lock_irqsave(&spi->lock, flags); if (spi->cur_bpw != transfer->bits_per_word) { spi->cur_bpw = transfer->bits_per_word; spi->cfg->set_bpw(spi); } if (spi->cur_speed != transfer->speed_hz) { int mbr; /* Update spi->cur_speed with real clock speed */ mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz, spi->cfg->baud_rate_div_min, spi->cfg->baud_rate_div_max); if (mbr < 0) { ret = mbr; goto out; } transfer->speed_hz = spi->cur_speed; stm32_spi_set_mbr(spi, mbr); } comm_type = stm32_spi_communication_type(spi_dev, transfer); if (spi->cur_comm != comm_type) { ret = spi->cfg->set_mode(spi, comm_type); if (ret < 0) goto out; spi->cur_comm = comm_type; } if (spi->cfg->set_data_idleness) spi->cfg->set_data_idleness(spi, transfer->len); if (spi->cur_bpw <= 8) nb_words = transfer->len; else if (spi->cur_bpw <= 16) nb_words = DIV_ROUND_UP(transfer->len * 8, 16); else nb_words = DIV_ROUND_UP(transfer->len * 8, 32); if (spi->cfg->set_number_of_data) { ret = spi->cfg->set_number_of_data(spi, nb_words); if (ret < 0) goto out; } spi->cur_xferlen = transfer->len; dev_dbg(spi->dev, "transfer communication mode set to %d\n", spi->cur_comm); dev_dbg(spi->dev, "data frame of %d-bit, data packet of %d data frames\n", spi->cur_bpw, spi->cur_fthlv); dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed); dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n", spi->cur_xferlen, nb_words); dev_dbg(spi->dev, "dma %s\n", (spi->cur_usedma) ? "enabled" : "disabled"); out: spin_unlock_irqrestore(&spi->lock, flags); return ret; } /** * stm32_spi_transfer_one - transfer a single spi_transfer * * It must return 0 if the transfer is finished or 1 if the transfer is still * in progress. */ static int stm32_spi_transfer_one(struct spi_master *master, struct spi_device *spi_dev, struct spi_transfer *transfer) { struct stm32_spi *spi = spi_master_get_devdata(master); int ret; spi->tx_buf = transfer->tx_buf; spi->rx_buf = transfer->rx_buf; spi->tx_len = spi->tx_buf ? transfer->len : 0; spi->rx_len = spi->rx_buf ? transfer->len : 0; spi->cur_usedma = (master->can_dma && master->can_dma(master, spi_dev, transfer)); ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer); if (ret) { dev_err(spi->dev, "SPI transfer setup failed\n"); return ret; } if (spi->cur_usedma) return stm32_spi_transfer_one_dma(spi, transfer); else return spi->cfg->transfer_one_irq(spi); } /** * stm32_spi_unprepare_msg - relax the hardware */ static int stm32_spi_unprepare_msg(struct spi_master *master, struct spi_message *msg) { struct stm32_spi *spi = spi_master_get_devdata(master); spi->cfg->disable(spi); return 0; } /** * stm32f4_spi_config - Configure SPI controller as SPI master */ static int stm32f4_spi_config(struct stm32_spi *spi) { unsigned long flags; spin_lock_irqsave(&spi->lock, flags); /* Ensure I2SMOD bit is kept cleared */ stm32_spi_clr_bits(spi, STM32F4_SPI_I2SCFGR, STM32F4_SPI_I2SCFGR_I2SMOD); /* * - SS input value high * - transmitter half duplex direction * - Set the master mode (default Motorola mode) * - Consider 1 master/n slaves configuration and * SS input value is determined by the SSI bit */ stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SSI | STM32F4_SPI_CR1_BIDIOE | STM32F4_SPI_CR1_MSTR | STM32F4_SPI_CR1_SSM); spin_unlock_irqrestore(&spi->lock, flags); return 0; } /** * stm32h7_spi_config - Configure SPI controller as SPI master */ static int stm32h7_spi_config(struct stm32_spi *spi) { unsigned long flags; spin_lock_irqsave(&spi->lock, flags); /* Ensure I2SMOD bit is kept cleared */ stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR, STM32H7_SPI_I2SCFGR_I2SMOD); /* * - SS input value high * - transmitter half duplex direction * - automatic communication suspend when RX-Fifo is full */ stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SSI | STM32H7_SPI_CR1_HDDIR | STM32H7_SPI_CR1_MASRX); /* * - Set the master mode (default Motorola mode) * - Consider 1 master/n slaves configuration and * SS input value is determined by the SSI bit * - keep control of all associated GPIOs */ stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_MASTER | STM32H7_SPI_CFG2_SSM | STM32H7_SPI_CFG2_AFCNTR); spin_unlock_irqrestore(&spi->lock, flags); return 0; } static const struct stm32_spi_cfg stm32f4_spi_cfg = { .regs = &stm32f4_spi_regspec, .get_bpw_mask = stm32f4_spi_get_bpw_mask, .disable = stm32f4_spi_disable, .config = stm32f4_spi_config, .set_bpw = stm32f4_spi_set_bpw, .set_mode = stm32f4_spi_set_mode, .transfer_one_dma_start = stm32f4_spi_transfer_one_dma_start, .dma_tx_cb = stm32f4_spi_dma_tx_cb, .dma_rx_cb = stm32f4_spi_dma_rx_cb, .transfer_one_irq = stm32f4_spi_transfer_one_irq, .irq_handler_event = stm32f4_spi_irq_event, .irq_handler_thread = stm32f4_spi_irq_thread, .baud_rate_div_min = STM32F4_SPI_BR_DIV_MIN, .baud_rate_div_max = STM32F4_SPI_BR_DIV_MAX, .has_fifo = false, }; static const struct stm32_spi_cfg stm32h7_spi_cfg = { .regs = &stm32h7_spi_regspec, .get_fifo_size = stm32h7_spi_get_fifo_size, .get_bpw_mask = stm32h7_spi_get_bpw_mask, .disable = stm32h7_spi_disable, .config = stm32h7_spi_config, .set_bpw = stm32h7_spi_set_bpw, .set_mode = stm32h7_spi_set_mode, .set_data_idleness = stm32h7_spi_data_idleness, .set_number_of_data = stm32h7_spi_number_of_data, .transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start, .dma_rx_cb = stm32h7_spi_dma_cb, .dma_tx_cb = stm32h7_spi_dma_cb, .transfer_one_irq = stm32h7_spi_transfer_one_irq, .irq_handler_thread = stm32h7_spi_irq_thread, .baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN, .baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX, .has_fifo = true, }; static const struct of_device_id stm32_spi_of_match[] = { { .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg }, { .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg }, {}, }; MODULE_DEVICE_TABLE(of, stm32_spi_of_match); static int stm32_spi_probe(struct platform_device *pdev) { struct spi_master *master; struct stm32_spi *spi; struct resource *res; int i, ret; master = spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi)); if (!master) { dev_err(&pdev->dev, "spi master allocation failed\n"); return -ENOMEM; } platform_set_drvdata(pdev, master); spi = spi_master_get_devdata(master); spi->dev = &pdev->dev; spi->master = master; spin_lock_init(&spi->lock); spi->cfg = (const struct stm32_spi_cfg *) of_match_device(pdev->dev.driver->of_match_table, &pdev->dev)->data; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); spi->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(spi->base)) { ret = PTR_ERR(spi->base); goto err_master_put; } spi->phys_addr = (dma_addr_t)res->start; spi->irq = platform_get_irq(pdev, 0); if (spi->irq <= 0) { ret = spi->irq; if (ret != -EPROBE_DEFER) dev_err(&pdev->dev, "failed to get irq: %d\n", ret); goto err_master_put; } ret = devm_request_threaded_irq(&pdev->dev, spi->irq, spi->cfg->irq_handler_event, spi->cfg->irq_handler_thread, IRQF_ONESHOT, pdev->name, master); if (ret) { dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq, ret); goto err_master_put; } spi->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(spi->clk)) { ret = PTR_ERR(spi->clk); dev_err(&pdev->dev, "clk get failed: %d\n", ret); goto err_master_put; } ret = clk_prepare_enable(spi->clk); if (ret) { dev_err(&pdev->dev, "clk enable failed: %d\n", ret); goto err_master_put; } spi->clk_rate = clk_get_rate(spi->clk); if (!spi->clk_rate) { dev_err(&pdev->dev, "clk rate = 0\n"); ret = -EINVAL; goto err_clk_disable; } spi->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (!IS_ERR(spi->rst)) { reset_control_assert(spi->rst); udelay(2); reset_control_deassert(spi->rst); } if (spi->cfg->has_fifo) spi->fifo_size = spi->cfg->get_fifo_size(spi); ret = spi->cfg->config(spi); if (ret) { dev_err(&pdev->dev, "controller configuration failed: %d\n", ret); goto err_clk_disable; } master->dev.of_node = pdev->dev.of_node; master->auto_runtime_pm = true; master->bus_num = pdev->id; master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST | SPI_3WIRE; master->bits_per_word_mask = spi->cfg->get_bpw_mask(spi); master->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min; master->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max; master->setup = stm32_spi_setup; master->prepare_message = stm32_spi_prepare_msg; master->transfer_one = stm32_spi_transfer_one; master->unprepare_message = stm32_spi_unprepare_msg; spi->dma_tx = dma_request_slave_channel(spi->dev, "tx"); if (!spi->dma_tx) dev_warn(&pdev->dev, "failed to request tx dma channel\n"); else master->dma_tx = spi->dma_tx; spi->dma_rx = dma_request_slave_channel(spi->dev, "rx"); if (!spi->dma_rx) dev_warn(&pdev->dev, "failed to request rx dma channel\n"); else master->dma_rx = spi->dma_rx; if (spi->dma_tx || spi->dma_rx) master->can_dma = stm32_spi_can_dma; pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); ret = devm_spi_register_master(&pdev->dev, master); if (ret) { dev_err(&pdev->dev, "spi master registration failed: %d\n", ret); goto err_dma_release; } if (!master->cs_gpios) { dev_err(&pdev->dev, "no CS gpios available\n"); ret = -EINVAL; goto err_dma_release; } for (i = 0; i < master->num_chipselect; i++) { if (!gpio_is_valid(master->cs_gpios[i])) { dev_err(&pdev->dev, "%i is not a valid gpio\n", master->cs_gpios[i]); ret = -EINVAL; goto err_dma_release; } ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i], DRIVER_NAME); if (ret) { dev_err(&pdev->dev, "can't get CS gpio %i\n", master->cs_gpios[i]); goto err_dma_release; } } dev_info(&pdev->dev, "driver initialized\n"); return 0; err_dma_release: if (spi->dma_tx) dma_release_channel(spi->dma_tx); if (spi->dma_rx) dma_release_channel(spi->dma_rx); pm_runtime_disable(&pdev->dev); err_clk_disable: clk_disable_unprepare(spi->clk); err_master_put: spi_master_put(master); return ret; } static int stm32_spi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct stm32_spi *spi = spi_master_get_devdata(master); spi->cfg->disable(spi); if (master->dma_tx) dma_release_channel(master->dma_tx); if (master->dma_rx) dma_release_channel(master->dma_rx); clk_disable_unprepare(spi->clk); pm_runtime_disable(&pdev->dev); return 0; } #ifdef CONFIG_PM static int stm32_spi_runtime_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct stm32_spi *spi = spi_master_get_devdata(master); clk_disable_unprepare(spi->clk); return 0; } static int stm32_spi_runtime_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct stm32_spi *spi = spi_master_get_devdata(master); return clk_prepare_enable(spi->clk); } #endif #ifdef CONFIG_PM_SLEEP static int stm32_spi_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); int ret; ret = spi_master_suspend(master); if (ret) return ret; return pm_runtime_force_suspend(dev); } static int stm32_spi_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct stm32_spi *spi = spi_master_get_devdata(master); int ret; ret = pm_runtime_force_resume(dev); if (ret) return ret; ret = spi_master_resume(master); if (ret) clk_disable_unprepare(spi->clk); return ret; } #endif static const struct dev_pm_ops stm32_spi_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume) SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend, stm32_spi_runtime_resume, NULL) }; static struct platform_driver stm32_spi_driver = { .probe = stm32_spi_probe, .remove = stm32_spi_remove, .driver = { .name = DRIVER_NAME, .pm = &stm32_spi_pm_ops, .of_match_table = stm32_spi_of_match, }, }; module_platform_driver(stm32_spi_driver); MODULE_ALIAS("platform:" DRIVER_NAME); MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver"); MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>"); MODULE_LICENSE("GPL v2");
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