| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sowjanya Komatineni | 3299 | 40.85% | 10 | 10.87% |
| Colin Cross | 1635 | 20.25% | 1 | 1.09% |
| Thierry Reding | 833 | 10.32% | 8 | 8.70% |
| Laxman Dewangan | 706 | 8.74% | 14 | 15.22% |
| Dmitry Osipenko | 425 | 5.26% | 11 | 11.96% |
| Shardar Shariff Md | 379 | 4.69% | 6 | 6.52% |
| Jon Hunter | 266 | 3.29% | 8 | 8.70% |
| Bitan Biswas | 163 | 2.02% | 5 | 5.43% |
| Mikko Perttunen | 140 | 1.73% | 1 | 1.09% |
| Stephen Warren | 71 | 0.88% | 4 | 4.35% |
| Todd Android Poynor | 41 | 0.51% | 1 | 1.09% |
| Wolfram Sang | 32 | 0.40% | 7 | 7.61% |
| John Bonesio | 20 | 0.25% | 2 | 2.17% |
| Doug Anderson | 17 | 0.21% | 1 | 1.09% |
| Kenneth Waters | 9 | 0.11% | 1 | 1.09% |
| Andy Shevchenko | 7 | 0.09% | 1 | 1.09% |
| Nicholas Mc Guire | 7 | 0.09% | 1 | 1.09% |
| Rafael J. Wysocki | 6 | 0.07% | 1 | 1.09% |
| Erik Gilling | 5 | 0.06% | 1 | 1.09% |
| Paul Gortmaker | 3 | 0.04% | 1 | 1.09% |
| Jay Cheng | 2 | 0.02% | 1 | 1.09% |
| Mike Rapoport | 2 | 0.02% | 1 | 1.09% |
| Colin Ian King | 2 | 0.02% | 1 | 1.09% |
| Peter Ujfalusi | 2 | 0.02% | 1 | 1.09% |
| Philipp Zabel | 1 | 0.01% | 1 | 1.09% |
| Olof Johansson | 1 | 0.01% | 1 | 1.09% |
| Bhumika Goyal | 1 | 0.01% | 1 | 1.09% |
| Total | 8075 | 92 |
// SPDX-License-Identifier: GPL-2.0 /* * drivers/i2c/busses/i2c-tegra.c * * Copyright (C) 2010 Google, Inc. * Author: Colin Cross <ccross@android.com> */ #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/ktime.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/reset.h> #define BYTES_PER_FIFO_WORD 4 #define I2C_CNFG 0x000 #define I2C_CNFG_DEBOUNCE_CNT GENMASK(14, 12) #define I2C_CNFG_PACKET_MODE_EN BIT(10) #define I2C_CNFG_NEW_MASTER_FSM BIT(11) #define I2C_CNFG_MULTI_MASTER_MODE BIT(17) #define I2C_STATUS 0x01c #define I2C_SL_CNFG 0x020 #define I2C_SL_CNFG_NACK BIT(1) #define I2C_SL_CNFG_NEWSL BIT(2) #define I2C_SL_ADDR1 0x02c #define I2C_SL_ADDR2 0x030 #define I2C_TLOW_SEXT 0x034 #define I2C_TX_FIFO 0x050 #define I2C_RX_FIFO 0x054 #define I2C_PACKET_TRANSFER_STATUS 0x058 #define I2C_FIFO_CONTROL 0x05c #define I2C_FIFO_CONTROL_TX_FLUSH BIT(1) #define I2C_FIFO_CONTROL_RX_FLUSH BIT(0) #define I2C_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 5) #define I2C_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 2) #define I2C_FIFO_STATUS 0x060 #define I2C_FIFO_STATUS_TX GENMASK(7, 4) #define I2C_FIFO_STATUS_RX GENMASK(3, 0) #define I2C_INT_MASK 0x064 #define I2C_INT_STATUS 0x068 #define I2C_INT_BUS_CLR_DONE BIT(11) #define I2C_INT_PACKET_XFER_COMPLETE BIT(7) #define I2C_INT_NO_ACK BIT(3) #define I2C_INT_ARBITRATION_LOST BIT(2) #define I2C_INT_TX_FIFO_DATA_REQ BIT(1) #define I2C_INT_RX_FIFO_DATA_REQ BIT(0) #define I2C_CLK_DIVISOR 0x06c #define I2C_CLK_DIVISOR_STD_FAST_MODE GENMASK(31, 16) #define I2C_CLK_DIVISOR_HSMODE GENMASK(15, 0) #define DVC_CTRL_REG1 0x000 #define DVC_CTRL_REG1_INTR_EN BIT(10) #define DVC_CTRL_REG3 0x008 #define DVC_CTRL_REG3_SW_PROG BIT(26) #define DVC_CTRL_REG3_I2C_DONE_INTR_EN BIT(30) #define DVC_STATUS 0x00c #define DVC_STATUS_I2C_DONE_INTR BIT(30) #define I2C_ERR_NONE 0x00 #define I2C_ERR_NO_ACK BIT(0) #define I2C_ERR_ARBITRATION_LOST BIT(1) #define I2C_ERR_UNKNOWN_INTERRUPT BIT(2) #define I2C_ERR_RX_BUFFER_OVERFLOW BIT(3) #define PACKET_HEADER0_HEADER_SIZE GENMASK(29, 28) #define PACKET_HEADER0_PACKET_ID GENMASK(23, 16) #define PACKET_HEADER0_CONT_ID GENMASK(15, 12) #define PACKET_HEADER0_PROTOCOL GENMASK(7, 4) #define PACKET_HEADER0_PROTOCOL_I2C 1 #define I2C_HEADER_CONT_ON_NAK BIT(21) #define I2C_HEADER_READ BIT(19) #define I2C_HEADER_10BIT_ADDR BIT(18) #define I2C_HEADER_IE_ENABLE BIT(17) #define I2C_HEADER_REPEAT_START BIT(16) #define I2C_HEADER_CONTINUE_XFER BIT(15) #define I2C_HEADER_SLAVE_ADDR_SHIFT 1 #define I2C_BUS_CLEAR_CNFG 0x084 #define I2C_BC_SCLK_THRESHOLD GENMASK(23, 16) #define I2C_BC_STOP_COND BIT(2) #define I2C_BC_TERMINATE BIT(1) #define I2C_BC_ENABLE BIT(0) #define I2C_BUS_CLEAR_STATUS 0x088 #define I2C_BC_STATUS BIT(0) #define I2C_CONFIG_LOAD 0x08c #define I2C_MSTR_CONFIG_LOAD BIT(0) #define I2C_CLKEN_OVERRIDE 0x090 #define I2C_MST_CORE_CLKEN_OVR BIT(0) #define I2C_INTERFACE_TIMING_0 0x094 #define I2C_INTERFACE_TIMING_THIGH GENMASK(13, 8) #define I2C_INTERFACE_TIMING_TLOW GENMASK(5, 0) #define I2C_INTERFACE_TIMING_1 0x098 #define I2C_INTERFACE_TIMING_TBUF GENMASK(29, 24) #define I2C_INTERFACE_TIMING_TSU_STO GENMASK(21, 16) #define I2C_INTERFACE_TIMING_THD_STA GENMASK(13, 8) #define I2C_INTERFACE_TIMING_TSU_STA GENMASK(5, 0) #define I2C_HS_INTERFACE_TIMING_0 0x09c #define I2C_HS_INTERFACE_TIMING_THIGH GENMASK(13, 8) #define I2C_HS_INTERFACE_TIMING_TLOW GENMASK(5, 0) #define I2C_HS_INTERFACE_TIMING_1 0x0a0 #define I2C_HS_INTERFACE_TIMING_TSU_STO GENMASK(21, 16) #define I2C_HS_INTERFACE_TIMING_THD_STA GENMASK(13, 8) #define I2C_HS_INTERFACE_TIMING_TSU_STA GENMASK(5, 0) #define I2C_MST_FIFO_CONTROL 0x0b4 #define I2C_MST_FIFO_CONTROL_RX_FLUSH BIT(0) #define I2C_MST_FIFO_CONTROL_TX_FLUSH BIT(1) #define I2C_MST_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 4) #define I2C_MST_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 16) #define I2C_MST_FIFO_STATUS 0x0b8 #define I2C_MST_FIFO_STATUS_TX GENMASK(23, 16) #define I2C_MST_FIFO_STATUS_RX GENMASK(7, 0) /* configuration load timeout in microseconds */ #define I2C_CONFIG_LOAD_TIMEOUT 1000000 /* Packet header size in bytes */ #define I2C_PACKET_HEADER_SIZE 12 /* * I2C Controller will use PIO mode for transfers up to 32 bytes in order to * avoid DMA overhead, otherwise external APB DMA controller will be used. * Note that the actual MAX PIO length is 20 bytes because 32 bytes include * I2C_PACKET_HEADER_SIZE. */ #define I2C_PIO_MODE_PREFERRED_LEN 32 /* * msg_end_type: The bus control which need to be send at end of transfer. * @MSG_END_STOP: Send stop pulse at end of transfer. * @MSG_END_REPEAT_START: Send repeat start at end of transfer. * @MSG_END_CONTINUE: The following on message is coming and so do not send * stop or repeat start. */ enum msg_end_type { MSG_END_STOP, MSG_END_REPEAT_START, MSG_END_CONTINUE, }; /** * struct tegra_i2c_hw_feature : Different HW support on Tegra * @has_continue_xfer_support: Continue transfer supports. * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer * complete interrupt per packet basis. * @has_single_clk_source: The I2C controller has single clock source. Tegra30 * and earlier SoCs have two clock sources i.e. div-clk and * fast-clk. * @has_config_load_reg: Has the config load register to load the new * configuration. * @clk_divisor_hs_mode: Clock divisor in HS mode. * @clk_divisor_std_mode: Clock divisor in standard mode. It is * applicable if there is no fast clock source i.e. single clock * source. * @clk_divisor_fast_mode: Clock divisor in fast mode. It is * applicable if there is no fast clock source i.e. single clock * source. * @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is * applicable if there is no fast clock source (i.e. single * clock source). * @has_multi_master_mode: The I2C controller supports running in single-master * or multi-master mode. * @has_slcg_override_reg: The I2C controller supports a register that * overrides the second level clock gating. * @has_mst_fifo: The I2C controller contains the new MST FIFO interface that * provides additional features and allows for longer messages to * be transferred in one go. * @quirks: i2c adapter quirks for limiting write/read transfer size and not * allowing 0 length transfers. * @supports_bus_clear: Bus Clear support to recover from bus hang during * SDA stuck low from device for some unknown reasons. * @has_apb_dma: Support of APBDMA on corresponding Tegra chip. * @tlow_std_mode: Low period of the clock in standard mode. * @thigh_std_mode: High period of the clock in standard mode. * @tlow_fast_fastplus_mode: Low period of the clock in fast/fast-plus modes. * @thigh_fast_fastplus_mode: High period of the clock in fast/fast-plus modes. * @setup_hold_time_std_mode: Setup and hold time for start and stop conditions * in standard mode. * @setup_hold_time_fast_fast_plus_mode: Setup and hold time for start and stop * conditions in fast/fast-plus modes. * @setup_hold_time_hs_mode: Setup and hold time for start and stop conditions * in HS mode. * @has_interface_timing_reg: Has interface timing register to program the tuned * timing settings. */ struct tegra_i2c_hw_feature { bool has_continue_xfer_support; bool has_per_pkt_xfer_complete_irq; bool has_single_clk_source; bool has_config_load_reg; int clk_divisor_hs_mode; int clk_divisor_std_mode; int clk_divisor_fast_mode; u16 clk_divisor_fast_plus_mode; bool has_multi_master_mode; bool has_slcg_override_reg; bool has_mst_fifo; const struct i2c_adapter_quirks *quirks; bool supports_bus_clear; bool has_apb_dma; u8 tlow_std_mode; u8 thigh_std_mode; u8 tlow_fast_fastplus_mode; u8 thigh_fast_fastplus_mode; u32 setup_hold_time_std_mode; u32 setup_hold_time_fast_fast_plus_mode; u32 setup_hold_time_hs_mode; bool has_interface_timing_reg; }; /** * struct tegra_i2c_dev - per device I2C context * @dev: device reference for power management * @hw: Tegra I2C HW feature * @adapter: core I2C layer adapter information * @div_clk: clock reference for div clock of I2C controller * @fast_clk: clock reference for fast clock of I2C controller * @rst: reset control for the I2C controller * @base: ioremapped registers cookie * @base_phys: physical base address of the I2C controller * @cont_id: I2C controller ID, used for packet header * @irq: IRQ number of transfer complete interrupt * @is_dvc: identifies the DVC I2C controller, has a different register layout * @is_vi: identifies the VI I2C controller, has a different register layout * @msg_complete: transfer completion notifier * @msg_err: error code for completed message * @msg_buf: pointer to current message data * @msg_buf_remaining: size of unsent data in the message buffer * @msg_read: identifies read transfers * @bus_clk_rate: current I2C bus clock rate * @clk_divisor_non_hs_mode: clock divider for non-high-speed modes * @is_multimaster_mode: track if I2C controller is in multi-master mode * @tx_dma_chan: DMA transmit channel * @rx_dma_chan: DMA receive channel * @dma_phys: handle to DMA resources * @dma_buf: pointer to allocated DMA buffer * @dma_buf_size: DMA buffer size * @is_curr_dma_xfer: indicates active DMA transfer * @dma_complete: DMA completion notifier * @is_curr_atomic_xfer: indicates active atomic transfer */ struct tegra_i2c_dev { struct device *dev; const struct tegra_i2c_hw_feature *hw; struct i2c_adapter adapter; struct clk *div_clk; struct clk *fast_clk; struct clk *slow_clk; struct reset_control *rst; void __iomem *base; phys_addr_t base_phys; int cont_id; int irq; int is_dvc; bool is_vi; struct completion msg_complete; int msg_err; u8 *msg_buf; size_t msg_buf_remaining; int msg_read; u32 bus_clk_rate; u16 clk_divisor_non_hs_mode; bool is_multimaster_mode; struct dma_chan *tx_dma_chan; struct dma_chan *rx_dma_chan; dma_addr_t dma_phys; u32 *dma_buf; unsigned int dma_buf_size; bool is_curr_dma_xfer; struct completion dma_complete; bool is_curr_atomic_xfer; }; static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg) { writel_relaxed(val, i2c_dev->base + reg); } static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg) { return readl_relaxed(i2c_dev->base + reg); } /* * i2c_writel and i2c_readl will offset the register if necessary to talk * to the I2C block inside the DVC block */ static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev, unsigned long reg) { if (i2c_dev->is_dvc) reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40; else if (i2c_dev->is_vi) reg = 0xc00 + (reg << 2); return reg; } static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg) { writel_relaxed(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg)); /* Read back register to make sure that register writes completed */ if (reg != I2C_TX_FIFO) readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg)); } static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg) { return readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg)); } static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data, unsigned long reg, int len) { writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len); } static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data, unsigned long reg, int len) { readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len); } static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask) { u32 int_mask; int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask; i2c_writel(i2c_dev, int_mask, I2C_INT_MASK); } static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask) { u32 int_mask; int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask; i2c_writel(i2c_dev, int_mask, I2C_INT_MASK); } static void tegra_i2c_dma_complete(void *args) { struct tegra_i2c_dev *i2c_dev = args; complete(&i2c_dev->dma_complete); } static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len) { struct dma_async_tx_descriptor *dma_desc; enum dma_transfer_direction dir; struct dma_chan *chan; dev_dbg(i2c_dev->dev, "starting DMA for length: %zu\n", len); reinit_completion(&i2c_dev->dma_complete); dir = i2c_dev->msg_read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV; chan = i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan; dma_desc = dmaengine_prep_slave_single(chan, i2c_dev->dma_phys, len, dir, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!dma_desc) { dev_err(i2c_dev->dev, "failed to get DMA descriptor\n"); return -EINVAL; } dma_desc->callback = tegra_i2c_dma_complete; dma_desc->callback_param = i2c_dev; dmaengine_submit(dma_desc); dma_async_issue_pending(chan); return 0; } static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev) { if (i2c_dev->dma_buf) { dma_free_coherent(i2c_dev->dev, i2c_dev->dma_buf_size, i2c_dev->dma_buf, i2c_dev->dma_phys); i2c_dev->dma_buf = NULL; } if (i2c_dev->tx_dma_chan) { dma_release_channel(i2c_dev->tx_dma_chan); i2c_dev->tx_dma_chan = NULL; } if (i2c_dev->rx_dma_chan) { dma_release_channel(i2c_dev->rx_dma_chan); i2c_dev->rx_dma_chan = NULL; } } static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev) { struct dma_chan *chan; u32 *dma_buf; dma_addr_t dma_phys; int err; if (!i2c_dev->hw->has_apb_dma) return 0; if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) { dev_dbg(i2c_dev->dev, "Support for APB DMA not enabled!\n"); return 0; } chan = dma_request_chan(i2c_dev->dev, "rx"); if (IS_ERR(chan)) { err = PTR_ERR(chan); goto err_out; } i2c_dev->rx_dma_chan = chan; chan = dma_request_chan(i2c_dev->dev, "tx"); if (IS_ERR(chan)) { err = PTR_ERR(chan); goto err_out; } i2c_dev->tx_dma_chan = chan; dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size, &dma_phys, GFP_KERNEL | __GFP_NOWARN); if (!dma_buf) { dev_err(i2c_dev->dev, "failed to allocate the DMA buffer\n"); err = -ENOMEM; goto err_out; } i2c_dev->dma_buf = dma_buf; i2c_dev->dma_phys = dma_phys; return 0; err_out: tegra_i2c_release_dma(i2c_dev); if (err != -EPROBE_DEFER) { dev_err(i2c_dev->dev, "cannot use DMA: %d\n", err); dev_err(i2c_dev->dev, "falling back to PIO\n"); return 0; } return err; } static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev) { unsigned long timeout = jiffies + HZ; unsigned int offset; u32 mask, val; if (i2c_dev->hw->has_mst_fifo) { mask = I2C_MST_FIFO_CONTROL_TX_FLUSH | I2C_MST_FIFO_CONTROL_RX_FLUSH; offset = I2C_MST_FIFO_CONTROL; } else { mask = I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH; offset = I2C_FIFO_CONTROL; } val = i2c_readl(i2c_dev, offset); val |= mask; i2c_writel(i2c_dev, val, offset); while (i2c_readl(i2c_dev, offset) & mask) { if (time_after(jiffies, timeout)) { dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n"); return -ETIMEDOUT; } usleep_range(1000, 2000); } return 0; } static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) { u32 val; int rx_fifo_avail; u8 *buf = i2c_dev->msg_buf; size_t buf_remaining = i2c_dev->msg_buf_remaining; int words_to_transfer; /* * Catch overflow due to message fully sent * before the check for RX FIFO availability. */ if (WARN_ON_ONCE(!(i2c_dev->msg_buf_remaining))) return -EINVAL; if (i2c_dev->hw->has_mst_fifo) { val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS); rx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_RX, val); } else { val = i2c_readl(i2c_dev, I2C_FIFO_STATUS); rx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_RX, val); } /* Rounds down to not include partial word at the end of buf */ words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD; if (words_to_transfer > rx_fifo_avail) words_to_transfer = rx_fifo_avail; i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer); buf += words_to_transfer * BYTES_PER_FIFO_WORD; buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD; rx_fifo_avail -= words_to_transfer; /* * If there is a partial word at the end of buf, handle it manually to * prevent overwriting past the end of buf */ if (rx_fifo_avail > 0 && buf_remaining > 0) { /* * buf_remaining > 3 check not needed as rx_fifo_avail == 0 * when (words_to_transfer was > rx_fifo_avail) earlier * in this function. */ val = i2c_readl(i2c_dev, I2C_RX_FIFO); val = cpu_to_le32(val); memcpy(buf, &val, buf_remaining); buf_remaining = 0; rx_fifo_avail--; } /* RX FIFO must be drained, otherwise it's an Overflow case. */ if (WARN_ON_ONCE(rx_fifo_avail)) return -EINVAL; i2c_dev->msg_buf_remaining = buf_remaining; i2c_dev->msg_buf = buf; return 0; } static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) { u32 val; int tx_fifo_avail; u8 *buf = i2c_dev->msg_buf; size_t buf_remaining = i2c_dev->msg_buf_remaining; int words_to_transfer; if (i2c_dev->hw->has_mst_fifo) { val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS); tx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_TX, val); } else { val = i2c_readl(i2c_dev, I2C_FIFO_STATUS); tx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_TX, val); } /* Rounds down to not include partial word at the end of buf */ words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD; /* It's very common to have < 4 bytes, so optimize that case. */ if (words_to_transfer) { if (words_to_transfer > tx_fifo_avail) words_to_transfer = tx_fifo_avail; /* * Update state before writing to FIFO. If this casues us * to finish writing all bytes (AKA buf_remaining goes to 0) we * have a potential for an interrupt (PACKET_XFER_COMPLETE is * not maskable). We need to make sure that the isr sees * buf_remaining as 0 and doesn't call us back re-entrantly. */ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD; tx_fifo_avail -= words_to_transfer; i2c_dev->msg_buf_remaining = buf_remaining; i2c_dev->msg_buf = buf + words_to_transfer * BYTES_PER_FIFO_WORD; barrier(); i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer); buf += words_to_transfer * BYTES_PER_FIFO_WORD; } /* * If there is a partial word at the end of buf, handle it manually to * prevent reading past the end of buf, which could cross a page * boundary and fault. */ if (tx_fifo_avail > 0 && buf_remaining > 0) { /* * buf_remaining > 3 check not needed as tx_fifo_avail == 0 * when (words_to_transfer was > tx_fifo_avail) earlier * in this function for non-zero words_to_transfer. */ memcpy(&val, buf, buf_remaining); val = le32_to_cpu(val); /* Again update before writing to FIFO to make sure isr sees. */ i2c_dev->msg_buf_remaining = 0; i2c_dev->msg_buf = NULL; barrier(); i2c_writel(i2c_dev, val, I2C_TX_FIFO); } return 0; } /* * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller) * block. This block is identical to the rest of the I2C blocks, except that * it only supports master mode, it has registers moved around, and it needs * some extra init to get it into I2C mode. The register moves are handled * by i2c_readl and i2c_writel */ static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev) { u32 val; val = dvc_readl(i2c_dev, DVC_CTRL_REG3); val |= DVC_CTRL_REG3_SW_PROG; val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN; dvc_writel(i2c_dev, val, DVC_CTRL_REG3); val = dvc_readl(i2c_dev, DVC_CTRL_REG1); val |= DVC_CTRL_REG1_INTR_EN; dvc_writel(i2c_dev, val, DVC_CTRL_REG1); } static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev) { struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); int ret; ret = pinctrl_pm_select_default_state(i2c_dev->dev); if (ret) return ret; if (!i2c_dev->hw->has_single_clk_source) { ret = clk_enable(i2c_dev->fast_clk); if (ret < 0) { dev_err(i2c_dev->dev, "Enabling fast clk failed, err %d\n", ret); return ret; } } if (i2c_dev->slow_clk) { ret = clk_enable(i2c_dev->slow_clk); if (ret < 0) { dev_err(dev, "failed to enable slow clock: %d\n", ret); return ret; } } ret = clk_enable(i2c_dev->div_clk); if (ret < 0) { dev_err(i2c_dev->dev, "Enabling div clk failed, err %d\n", ret); clk_disable(i2c_dev->fast_clk); return ret; } return 0; } static int __maybe_unused tegra_i2c_runtime_suspend(struct device *dev) { struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); clk_disable(i2c_dev->div_clk); if (i2c_dev->slow_clk) clk_disable(i2c_dev->slow_clk); if (!i2c_dev->hw->has_single_clk_source) clk_disable(i2c_dev->fast_clk); return pinctrl_pm_select_idle_state(i2c_dev->dev); } static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev) { unsigned long reg_offset; void __iomem *addr; u32 val; int err; if (i2c_dev->hw->has_config_load_reg) { reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD); addr = i2c_dev->base + reg_offset; i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD); if (i2c_dev->is_curr_atomic_xfer) err = readl_relaxed_poll_timeout_atomic( addr, val, val == 0, 1000, I2C_CONFIG_LOAD_TIMEOUT); else err = readl_relaxed_poll_timeout( addr, val, val == 0, 1000, I2C_CONFIG_LOAD_TIMEOUT); if (err) { dev_warn(i2c_dev->dev, "timeout waiting for config load\n"); return err; } } return 0; } static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev) { u32 value; value = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, 2) | FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, 4); i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_0); value = FIELD_PREP(I2C_INTERFACE_TIMING_TBUF, 4) | FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STO, 7) | FIELD_PREP(I2C_INTERFACE_TIMING_THD_STA, 4) | FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STA, 4); i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_1); value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_THIGH, 3) | FIELD_PREP(I2C_HS_INTERFACE_TIMING_TLOW, 8); i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_0); value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STO, 11) | FIELD_PREP(I2C_HS_INTERFACE_TIMING_THD_STA, 11) | FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STA, 11); i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_1); value = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND; i2c_writel(i2c_dev, value, I2C_BUS_CLEAR_CNFG); i2c_writel(i2c_dev, 0x0, I2C_TLOW_SEXT); } static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit) { u32 val; int err; u32 clk_divisor, clk_multiplier; u32 tsu_thd; u8 tlow, thigh; reset_control_assert(i2c_dev->rst); udelay(2); reset_control_deassert(i2c_dev->rst); if (i2c_dev->is_dvc) tegra_dvc_init(i2c_dev); val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN | FIELD_PREP(I2C_CNFG_DEBOUNCE_CNT, 2); if (i2c_dev->hw->has_multi_master_mode) val |= I2C_CNFG_MULTI_MASTER_MODE; i2c_writel(i2c_dev, val, I2C_CNFG); i2c_writel(i2c_dev, 0, I2C_INT_MASK); if (i2c_dev->is_vi) tegra_i2c_vi_init(i2c_dev); /* Make sure clock divisor programmed correctly */ clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE, i2c_dev->hw->clk_divisor_hs_mode) | FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, i2c_dev->clk_divisor_non_hs_mode); i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR); if (i2c_dev->bus_clk_rate > I2C_MAX_STANDARD_MODE_FREQ && i2c_dev->bus_clk_rate <= I2C_MAX_FAST_MODE_PLUS_FREQ) { tlow = i2c_dev->hw->tlow_fast_fastplus_mode; thigh = i2c_dev->hw->thigh_fast_fastplus_mode; tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode; } else { tlow = i2c_dev->hw->tlow_std_mode; thigh = i2c_dev->hw->thigh_std_mode; tsu_thd = i2c_dev->hw->setup_hold_time_std_mode; } if (i2c_dev->hw->has_interface_timing_reg) { val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) | FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow); i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0); } /* * configure setup and hold times only when tsu_thd is non-zero. * otherwise, preserve the chip default values */ if (i2c_dev->hw->has_interface_timing_reg && tsu_thd) i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1); if (!clk_reinit) { clk_multiplier = (tlow + thigh + 2); clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1); err = clk_set_rate(i2c_dev->div_clk, i2c_dev->bus_clk_rate * clk_multiplier); if (err) { dev_err(i2c_dev->dev, "failed changing clock rate: %d\n", err); return err; } } if (!i2c_dev->is_dvc && !i2c_dev->is_vi) { u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG); sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL; i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG); i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1); i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2); } err = tegra_i2c_flush_fifos(i2c_dev); if (err) return err; if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg) i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE); err = tegra_i2c_wait_for_config_load(i2c_dev); if (err) return err; return 0; } static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev) { u32 cnfg; /* * NACK interrupt is generated before the I2C controller generates * the STOP condition on the bus. So wait for 2 clock periods * before disabling the controller so that the STOP condition has * been delivered properly. */ udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate)); cnfg = i2c_readl(i2c_dev, I2C_CNFG); if (cnfg & I2C_CNFG_PACKET_MODE_EN) i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG); return tegra_i2c_wait_for_config_load(i2c_dev); } static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) { u32 status; const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST; struct tegra_i2c_dev *i2c_dev = dev_id; status = i2c_readl(i2c_dev, I2C_INT_STATUS); if (status == 0) { dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n", i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS), i2c_readl(i2c_dev, I2C_STATUS), i2c_readl(i2c_dev, I2C_CNFG)); i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT; goto err; } if (unlikely(status & status_err)) { tegra_i2c_disable_packet_mode(i2c_dev); if (status & I2C_INT_NO_ACK) i2c_dev->msg_err |= I2C_ERR_NO_ACK; if (status & I2C_INT_ARBITRATION_LOST) i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST; goto err; } /* * I2C transfer is terminated during the bus clear so skip * processing the other interrupts. */ if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE)) goto err; if (!i2c_dev->is_curr_dma_xfer) { if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) { if (tegra_i2c_empty_rx_fifo(i2c_dev)) { /* * Overflow error condition: message fully sent, * with no XFER_COMPLETE interrupt but hardware * asks to transfer more. */ i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW; goto err; } } if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) { if (i2c_dev->msg_buf_remaining) tegra_i2c_fill_tx_fifo(i2c_dev); else tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ); } } i2c_writel(i2c_dev, status, I2C_INT_STATUS); if (i2c_dev->is_dvc) dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS); /* * During message read XFER_COMPLETE interrupt is triggered prior to * DMA completion and during message write XFER_COMPLETE interrupt is * triggered after DMA completion. * PACKETS_XFER_COMPLETE indicates completion of all bytes of transfer. * so forcing msg_buf_remaining to 0 in DMA mode. */ if (status & I2C_INT_PACKET_XFER_COMPLETE) { if (i2c_dev->is_curr_dma_xfer) i2c_dev->msg_buf_remaining = 0; /* * Underflow error condition: XFER_COMPLETE before message * fully sent. */ if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) { i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT; goto err; } complete(&i2c_dev->msg_complete); } goto done; err: /* An error occurred, mask all interrupts */ tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST | I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ | I2C_INT_RX_FIFO_DATA_REQ); if (i2c_dev->hw->supports_bus_clear) tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE); i2c_writel(i2c_dev, status, I2C_INT_STATUS); if (i2c_dev->is_dvc) dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS); if (i2c_dev->is_curr_dma_xfer) { if (i2c_dev->msg_read) dmaengine_terminate_async(i2c_dev->rx_dma_chan); else dmaengine_terminate_async(i2c_dev->tx_dma_chan); complete(&i2c_dev->dma_complete); } complete(&i2c_dev->msg_complete); done: return IRQ_HANDLED; } static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev, size_t len) { u32 val, reg; u8 dma_burst; struct dma_slave_config slv_config = {0}; struct dma_chan *chan; int ret; unsigned long reg_offset; if (i2c_dev->hw->has_mst_fifo) reg = I2C_MST_FIFO_CONTROL; else reg = I2C_FIFO_CONTROL; if (i2c_dev->is_curr_dma_xfer) { if (len & 0xF) dma_burst = 1; else if (len & 0x10) dma_burst = 4; else dma_burst = 8; if (i2c_dev->msg_read) { chan = i2c_dev->rx_dma_chan; reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_RX_FIFO); slv_config.src_addr = i2c_dev->base_phys + reg_offset; slv_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; slv_config.src_maxburst = dma_burst; if (i2c_dev->hw->has_mst_fifo) val = I2C_MST_FIFO_CONTROL_RX_TRIG(dma_burst); else val = I2C_FIFO_CONTROL_RX_TRIG(dma_burst); } else { chan = i2c_dev->tx_dma_chan; reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_TX_FIFO); slv_config.dst_addr = i2c_dev->base_phys + reg_offset; slv_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; slv_config.dst_maxburst = dma_burst; if (i2c_dev->hw->has_mst_fifo) val = I2C_MST_FIFO_CONTROL_TX_TRIG(dma_burst); else val = I2C_FIFO_CONTROL_TX_TRIG(dma_burst); } slv_config.device_fc = true; ret = dmaengine_slave_config(chan, &slv_config); if (ret < 0) { dev_err(i2c_dev->dev, "DMA slave config failed: %d\n", ret); dev_err(i2c_dev->dev, "falling back to PIO\n"); tegra_i2c_release_dma(i2c_dev); i2c_dev->is_curr_dma_xfer = false; } else { goto out; } } if (i2c_dev->hw->has_mst_fifo) val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) | I2C_MST_FIFO_CONTROL_RX_TRIG(1); else val = I2C_FIFO_CONTROL_TX_TRIG(8) | I2C_FIFO_CONTROL_RX_TRIG(1); out: i2c_writel(i2c_dev, val, reg); } static unsigned long tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev, struct completion *complete, unsigned int timeout_ms) { ktime_t ktime = ktime_get(); ktime_t ktimeout = ktime_add_ms(ktime, timeout_ms); do { u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS); if (status) tegra_i2c_isr(i2c_dev->irq, i2c_dev); if (completion_done(complete)) { s64 delta = ktime_ms_delta(ktimeout, ktime); return msecs_to_jiffies(delta) ?: 1; } ktime = ktime_get(); } while (ktime_before(ktime, ktimeout)); return 0; } static unsigned long tegra_i2c_wait_completion_timeout(struct tegra_i2c_dev *i2c_dev, struct completion *complete, unsigned int timeout_ms) { unsigned long ret; if (i2c_dev->is_curr_atomic_xfer) { ret = tegra_i2c_poll_completion_timeout(i2c_dev, complete, timeout_ms); } else { enable_irq(i2c_dev->irq); ret = wait_for_completion_timeout(complete, msecs_to_jiffies(timeout_ms)); disable_irq(i2c_dev->irq); /* * Under some rare circumstances (like running KASAN + * NFS root) CPU, which handles interrupt, may stuck in * uninterruptible state for a significant time. In this * case we will get timeout if I2C transfer is running on * a sibling CPU, despite of IRQ being raised. * * In order to handle this rare condition, the IRQ status * needs to be checked after timeout. */ if (ret == 0) ret = tegra_i2c_poll_completion_timeout(i2c_dev, complete, 0); } return ret; } static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap) { struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); int err; unsigned long time_left; u32 reg; reinit_completion(&i2c_dev->msg_complete); reg = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND | I2C_BC_TERMINATE; i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG); if (i2c_dev->hw->has_config_load_reg) { err = tegra_i2c_wait_for_config_load(i2c_dev); if (err) return err; } reg |= I2C_BC_ENABLE; i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG); tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE); time_left = tegra_i2c_wait_completion_timeout( i2c_dev, &i2c_dev->msg_complete, 50); if (time_left == 0) { dev_err(i2c_dev->dev, "timed out for bus clear\n"); return -ETIMEDOUT; } reg = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS); if (!(reg & I2C_BC_STATUS)) { dev_err(i2c_dev->dev, "un-recovered arbitration lost\n"); return -EIO; } return -EAGAIN; } static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, struct i2c_msg *msg, enum msg_end_type end_state) { u32 packet_header; u32 int_mask; unsigned long time_left; size_t xfer_size; u32 *buffer = NULL; int err = 0; bool dma; u16 xfer_time = 100; tegra_i2c_flush_fifos(i2c_dev); i2c_dev->msg_buf = msg->buf; i2c_dev->msg_buf_remaining = msg->len; i2c_dev->msg_err = I2C_ERR_NONE; i2c_dev->msg_read = (msg->flags & I2C_M_RD); reinit_completion(&i2c_dev->msg_complete); if (i2c_dev->msg_read) xfer_size = msg->len; else xfer_size = msg->len + I2C_PACKET_HEADER_SIZE; xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD); i2c_dev->is_curr_dma_xfer = (xfer_size > I2C_PIO_MODE_PREFERRED_LEN) && i2c_dev->dma_buf && !i2c_dev->is_curr_atomic_xfer; tegra_i2c_config_fifo_trig(i2c_dev, xfer_size); dma = i2c_dev->is_curr_dma_xfer; /* * Transfer time in mSec = Total bits / transfer rate * Total bits = 9 bits per byte (including ACK bit) + Start & stop bits */ xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC, i2c_dev->bus_clk_rate); int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST; tegra_i2c_unmask_irq(i2c_dev, int_mask); if (dma) { if (i2c_dev->msg_read) { dma_sync_single_for_device(i2c_dev->dev, i2c_dev->dma_phys, xfer_size, DMA_FROM_DEVICE); err = tegra_i2c_dma_submit(i2c_dev, xfer_size); if (err < 0) { dev_err(i2c_dev->dev, "starting RX DMA failed, err %d\n", err); return err; } } else { dma_sync_single_for_cpu(i2c_dev->dev, i2c_dev->dma_phys, xfer_size, DMA_TO_DEVICE); buffer = i2c_dev->dma_buf; } } packet_header = FIELD_PREP(PACKET_HEADER0_HEADER_SIZE, 0) | FIELD_PREP(PACKET_HEADER0_PROTOCOL, PACKET_HEADER0_PROTOCOL_I2C) | FIELD_PREP(PACKET_HEADER0_CONT_ID, i2c_dev->cont_id) | FIELD_PREP(PACKET_HEADER0_PACKET_ID, 1); if (dma && !i2c_dev->msg_read) *buffer++ = packet_header; else i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); packet_header = msg->len - 1; if (dma && !i2c_dev->msg_read) *buffer++ = packet_header; else i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); packet_header = I2C_HEADER_IE_ENABLE; if (end_state == MSG_END_CONTINUE) packet_header |= I2C_HEADER_CONTINUE_XFER; else if (end_state == MSG_END_REPEAT_START) packet_header |= I2C_HEADER_REPEAT_START; if (msg->flags & I2C_M_TEN) { packet_header |= msg->addr; packet_header |= I2C_HEADER_10BIT_ADDR; } else { packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT; } if (msg->flags & I2C_M_IGNORE_NAK) packet_header |= I2C_HEADER_CONT_ON_NAK; if (msg->flags & I2C_M_RD) packet_header |= I2C_HEADER_READ; if (dma && !i2c_dev->msg_read) *buffer++ = packet_header; else i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO); if (!i2c_dev->msg_read) { if (dma) { memcpy(buffer, msg->buf, msg->len); dma_sync_single_for_device(i2c_dev->dev, i2c_dev->dma_phys, xfer_size, DMA_TO_DEVICE); err = tegra_i2c_dma_submit(i2c_dev, xfer_size); if (err < 0) { dev_err(i2c_dev->dev, "starting TX DMA failed, err %d\n", err); return err; } } else { tegra_i2c_fill_tx_fifo(i2c_dev); } } if (i2c_dev->hw->has_per_pkt_xfer_complete_irq) int_mask |= I2C_INT_PACKET_XFER_COMPLETE; if (!dma) { if (msg->flags & I2C_M_RD) int_mask |= I2C_INT_RX_FIFO_DATA_REQ; else if (i2c_dev->msg_buf_remaining) int_mask |= I2C_INT_TX_FIFO_DATA_REQ; } tegra_i2c_unmask_irq(i2c_dev, int_mask); dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n", i2c_readl(i2c_dev, I2C_INT_MASK)); if (dma) { time_left = tegra_i2c_wait_completion_timeout( i2c_dev, &i2c_dev->dma_complete, xfer_time); /* * Synchronize DMA first, since dmaengine_terminate_sync() * performs synchronization after the transfer's termination * and we want to get a completion if transfer succeeded. */ dmaengine_synchronize(i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan); dmaengine_terminate_sync(i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan); if (!time_left && !completion_done(&i2c_dev->dma_complete)) { dev_err(i2c_dev->dev, "DMA transfer timeout\n"); tegra_i2c_init(i2c_dev, true); return -ETIMEDOUT; } if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) { dma_sync_single_for_cpu(i2c_dev->dev, i2c_dev->dma_phys, xfer_size, DMA_FROM_DEVICE); memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf, msg->len); } } time_left = tegra_i2c_wait_completion_timeout( i2c_dev, &i2c_dev->msg_complete, xfer_time); tegra_i2c_mask_irq(i2c_dev, int_mask); if (time_left == 0) { dev_err(i2c_dev->dev, "i2c transfer timed out\n"); tegra_i2c_init(i2c_dev, true); return -ETIMEDOUT; } dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n", time_left, completion_done(&i2c_dev->msg_complete), i2c_dev->msg_err); i2c_dev->is_curr_dma_xfer = false; if (likely(i2c_dev->msg_err == I2C_ERR_NONE)) return 0; tegra_i2c_init(i2c_dev, true); /* start recovery upon arbitration loss in single master mode */ if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) { if (!i2c_dev->is_multimaster_mode) return i2c_recover_bus(&i2c_dev->adapter); return -EAGAIN; } if (i2c_dev->msg_err == I2C_ERR_NO_ACK) { if (msg->flags & I2C_M_IGNORE_NAK) return 0; return -EREMOTEIO; } return -EIO; } static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); int i; int ret; ret = pm_runtime_get_sync(i2c_dev->dev); if (ret < 0) { dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret); return ret; } for (i = 0; i < num; i++) { enum msg_end_type end_type = MSG_END_STOP; if (i < (num - 1)) { if (msgs[i + 1].flags & I2C_M_NOSTART) end_type = MSG_END_CONTINUE; else end_type = MSG_END_REPEAT_START; } ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type); if (ret) break; } pm_runtime_put(i2c_dev->dev); return ret ?: i; } static int tegra_i2c_xfer_atomic(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); int ret; i2c_dev->is_curr_atomic_xfer = true; ret = tegra_i2c_xfer(adap, msgs, num); i2c_dev->is_curr_atomic_xfer = false; return ret; } static u32 tegra_i2c_func(struct i2c_adapter *adap) { struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; if (i2c_dev->hw->has_continue_xfer_support) ret |= I2C_FUNC_NOSTART; return ret; } static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev) { struct device_node *np = i2c_dev->dev->of_node; int ret; bool multi_mode; ret = of_property_read_u32(np, "clock-frequency", &i2c_dev->bus_clk_rate); if (ret) i2c_dev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ; /* default clock rate */ multi_mode = of_property_read_bool(np, "multi-master"); i2c_dev->is_multimaster_mode = multi_mode; } static const struct i2c_algorithm tegra_i2c_algo = { .master_xfer = tegra_i2c_xfer, .master_xfer_atomic = tegra_i2c_xfer_atomic, .functionality = tegra_i2c_func, }; /* payload size is only 12 bit */ static const struct i2c_adapter_quirks tegra_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, .max_read_len = SZ_4K, .max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE, }; static const struct i2c_adapter_quirks tegra194_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, .max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE, }; static struct i2c_bus_recovery_info tegra_i2c_recovery_info = { .recover_bus = tegra_i2c_issue_bus_clear, }; static const struct tegra_i2c_hw_feature tegra20_i2c_hw = { .has_continue_xfer_support = false, .has_per_pkt_xfer_complete_irq = false, .has_single_clk_source = false, .clk_divisor_hs_mode = 3, .clk_divisor_std_mode = 0, .clk_divisor_fast_mode = 0, .clk_divisor_fast_plus_mode = 0, .has_config_load_reg = false, .has_multi_master_mode = false, .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = false, .has_apb_dma = true, .tlow_std_mode = 0x4, .thigh_std_mode = 0x2, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0x0, .setup_hold_time_fast_fast_plus_mode = 0x0, .setup_hold_time_hs_mode = 0x0, .has_interface_timing_reg = false, }; static const struct tegra_i2c_hw_feature tegra30_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = false, .has_single_clk_source = false, .clk_divisor_hs_mode = 3, .clk_divisor_std_mode = 0, .clk_divisor_fast_mode = 0, .clk_divisor_fast_plus_mode = 0, .has_config_load_reg = false, .has_multi_master_mode = false, .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = false, .has_apb_dma = true, .tlow_std_mode = 0x4, .thigh_std_mode = 0x2, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0x0, .setup_hold_time_fast_fast_plus_mode = 0x0, .setup_hold_time_hs_mode = 0x0, .has_interface_timing_reg = false, }; static const struct tegra_i2c_hw_feature tegra114_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = true, .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_mode = 0x19, .clk_divisor_fast_mode = 0x19, .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = false, .has_multi_master_mode = false, .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = true, .has_apb_dma = true, .tlow_std_mode = 0x4, .thigh_std_mode = 0x2, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0x0, .setup_hold_time_fast_fast_plus_mode = 0x0, .setup_hold_time_hs_mode = 0x0, .has_interface_timing_reg = false, }; static const struct tegra_i2c_hw_feature tegra124_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = true, .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_mode = 0x19, .clk_divisor_fast_mode = 0x19, .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = true, .has_multi_master_mode = false, .has_slcg_override_reg = true, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = true, .has_apb_dma = true, .tlow_std_mode = 0x4, .thigh_std_mode = 0x2, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0x0, .setup_hold_time_fast_fast_plus_mode = 0x0, .setup_hold_time_hs_mode = 0x0, .has_interface_timing_reg = true, }; static const struct tegra_i2c_hw_feature tegra210_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = true, .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_mode = 0x19, .clk_divisor_fast_mode = 0x19, .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = true, .has_multi_master_mode = false, .has_slcg_override_reg = true, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = true, .has_apb_dma = true, .tlow_std_mode = 0x4, .thigh_std_mode = 0x2, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0, .setup_hold_time_fast_fast_plus_mode = 0, .setup_hold_time_hs_mode = 0, .has_interface_timing_reg = true, }; static const struct tegra_i2c_hw_feature tegra186_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = true, .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_mode = 0x16, .clk_divisor_fast_mode = 0x19, .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = true, .has_multi_master_mode = false, .has_slcg_override_reg = true, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, .supports_bus_clear = true, .has_apb_dma = false, .tlow_std_mode = 0x4, .thigh_std_mode = 0x3, .tlow_fast_fastplus_mode = 0x4, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0, .setup_hold_time_fast_fast_plus_mode = 0, .setup_hold_time_hs_mode = 0, .has_interface_timing_reg = true, }; static const struct tegra_i2c_hw_feature tegra194_i2c_hw = { .has_continue_xfer_support = true, .has_per_pkt_xfer_complete_irq = true, .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_mode = 0x4f, .clk_divisor_fast_mode = 0x3c, .clk_divisor_fast_plus_mode = 0x16, .has_config_load_reg = true, .has_multi_master_mode = true, .has_slcg_override_reg = true, .has_mst_fifo = true, .quirks = &tegra194_i2c_quirks, .supports_bus_clear = true, .has_apb_dma = false, .tlow_std_mode = 0x8, .thigh_std_mode = 0x7, .tlow_fast_fastplus_mode = 0x2, .thigh_fast_fastplus_mode = 0x2, .setup_hold_time_std_mode = 0x08080808, .setup_hold_time_fast_fast_plus_mode = 0x02020202, .setup_hold_time_hs_mode = 0x090909, .has_interface_timing_reg = true, }; /* Match table for of_platform binding */ static const struct of_device_id tegra_i2c_of_match[] = { { .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, }, { .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, }, { .compatible = "nvidia,tegra210-i2c-vi", .data = &tegra210_i2c_hw, }, { .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, }, { .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, }, { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, }, { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, }, { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, }, { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, }, {}, }; MODULE_DEVICE_TABLE(of, tegra_i2c_of_match); static int tegra_i2c_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct tegra_i2c_dev *i2c_dev; struct resource *res; struct clk *div_clk; struct clk *fast_clk; void __iomem *base; phys_addr_t base_phys; int irq; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base_phys = res->start; base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) return PTR_ERR(base); res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!res) { dev_err(&pdev->dev, "no irq resource\n"); return -EINVAL; } irq = res->start; div_clk = devm_clk_get(&pdev->dev, "div-clk"); if (IS_ERR(div_clk)) { if (PTR_ERR(div_clk) != -EPROBE_DEFER) dev_err(&pdev->dev, "missing controller clock\n"); return PTR_ERR(div_clk); } i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) return -ENOMEM; i2c_dev->base = base; i2c_dev->base_phys = base_phys; i2c_dev->div_clk = div_clk; i2c_dev->adapter.algo = &tegra_i2c_algo; i2c_dev->adapter.retries = 1; i2c_dev->adapter.timeout = 6 * HZ; i2c_dev->irq = irq; i2c_dev->cont_id = pdev->id; i2c_dev->dev = &pdev->dev; i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c"); if (IS_ERR(i2c_dev->rst)) { dev_err(&pdev->dev, "missing controller reset\n"); return PTR_ERR(i2c_dev->rst); } tegra_i2c_parse_dt(i2c_dev); i2c_dev->hw = of_device_get_match_data(&pdev->dev); i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node, "nvidia,tegra20-i2c-dvc"); i2c_dev->is_vi = of_device_is_compatible(dev->of_node, "nvidia,tegra210-i2c-vi"); i2c_dev->adapter.quirks = i2c_dev->hw->quirks; i2c_dev->dma_buf_size = i2c_dev->adapter.quirks->max_write_len + I2C_PACKET_HEADER_SIZE; init_completion(&i2c_dev->msg_complete); init_completion(&i2c_dev->dma_complete); if (!i2c_dev->hw->has_single_clk_source) { fast_clk = devm_clk_get(&pdev->dev, "fast-clk"); if (IS_ERR(fast_clk)) { dev_err(&pdev->dev, "missing fast clock\n"); return PTR_ERR(fast_clk); } i2c_dev->fast_clk = fast_clk; } if (i2c_dev->is_vi) { i2c_dev->slow_clk = devm_clk_get(dev, "slow"); if (IS_ERR(i2c_dev->slow_clk)) { if (PTR_ERR(i2c_dev->slow_clk) != -EPROBE_DEFER) dev_err(dev, "failed to get slow clock: %ld\n", PTR_ERR(i2c_dev->slow_clk)); return PTR_ERR(i2c_dev->slow_clk); } } platform_set_drvdata(pdev, i2c_dev); if (!i2c_dev->hw->has_single_clk_source) { ret = clk_prepare(i2c_dev->fast_clk); if (ret < 0) { dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret); return ret; } } if (i2c_dev->slow_clk) { ret = clk_prepare(i2c_dev->slow_clk); if (ret < 0) { dev_err(dev, "failed to prepare slow clock: %d\n", ret); goto unprepare_fast_clk; } } if (i2c_dev->bus_clk_rate > I2C_MAX_FAST_MODE_FREQ && i2c_dev->bus_clk_rate <= I2C_MAX_FAST_MODE_PLUS_FREQ) i2c_dev->clk_divisor_non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode; else if (i2c_dev->bus_clk_rate > I2C_MAX_STANDARD_MODE_FREQ && i2c_dev->bus_clk_rate <= I2C_MAX_FAST_MODE_FREQ) i2c_dev->clk_divisor_non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode; else i2c_dev->clk_divisor_non_hs_mode = i2c_dev->hw->clk_divisor_std_mode; ret = clk_prepare(i2c_dev->div_clk); if (ret < 0) { dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret); goto unprepare_slow_clk; } pm_runtime_irq_safe(&pdev->dev); pm_runtime_enable(&pdev->dev); if (!pm_runtime_enabled(&pdev->dev)) { ret = tegra_i2c_runtime_resume(&pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "runtime resume failed\n"); goto unprepare_div_clk; } } else { ret = pm_runtime_get_sync(i2c_dev->dev); if (ret < 0) { dev_err(&pdev->dev, "runtime resume failed\n"); goto disable_rpm; } } if (i2c_dev->is_multimaster_mode) { ret = clk_enable(i2c_dev->div_clk); if (ret < 0) { dev_err(i2c_dev->dev, "div_clk enable failed %d\n", ret); goto put_rpm; } } if (i2c_dev->hw->supports_bus_clear) i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info; ret = tegra_i2c_init_dma(i2c_dev); if (ret < 0) goto disable_div_clk; ret = tegra_i2c_init(i2c_dev, false); if (ret) { dev_err(&pdev->dev, "Failed to initialize i2c controller\n"); goto release_dma; } irq_set_status_flags(i2c_dev->irq, IRQ_NOAUTOEN); ret = devm_request_irq(&pdev->dev, i2c_dev->irq, tegra_i2c_isr, IRQF_NO_SUSPEND, dev_name(&pdev->dev), i2c_dev); if (ret) { dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq); goto release_dma; } i2c_set_adapdata(&i2c_dev->adapter, i2c_dev); i2c_dev->adapter.owner = THIS_MODULE; i2c_dev->adapter.class = I2C_CLASS_DEPRECATED; strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev), sizeof(i2c_dev->adapter.name)); i2c_dev->adapter.dev.parent = &pdev->dev; i2c_dev->adapter.nr = pdev->id; i2c_dev->adapter.dev.of_node = pdev->dev.of_node; ret = i2c_add_numbered_adapter(&i2c_dev->adapter); if (ret) goto release_dma; pm_runtime_put(&pdev->dev); return 0; release_dma: tegra_i2c_release_dma(i2c_dev); disable_div_clk: if (i2c_dev->is_multimaster_mode) clk_disable(i2c_dev->div_clk); put_rpm: if (pm_runtime_enabled(&pdev->dev)) pm_runtime_put_sync(&pdev->dev); else tegra_i2c_runtime_suspend(&pdev->dev); disable_rpm: if (pm_runtime_enabled(&pdev->dev)) pm_runtime_disable(&pdev->dev); unprepare_div_clk: clk_unprepare(i2c_dev->div_clk); unprepare_slow_clk: if (i2c_dev->is_vi) clk_unprepare(i2c_dev->slow_clk); unprepare_fast_clk: if (!i2c_dev->hw->has_single_clk_source) clk_unprepare(i2c_dev->fast_clk); return ret; } static int tegra_i2c_remove(struct platform_device *pdev) { struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev); i2c_del_adapter(&i2c_dev->adapter); if (i2c_dev->is_multimaster_mode) clk_disable(i2c_dev->div_clk); pm_runtime_disable(&pdev->dev); if (!pm_runtime_status_suspended(&pdev->dev)) tegra_i2c_runtime_suspend(&pdev->dev); clk_unprepare(i2c_dev->div_clk); if (i2c_dev->slow_clk) clk_unprepare(i2c_dev->slow_clk); if (!i2c_dev->hw->has_single_clk_source) clk_unprepare(i2c_dev->fast_clk); tegra_i2c_release_dma(i2c_dev); return 0; } static int __maybe_unused tegra_i2c_suspend(struct device *dev) { struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); int err = 0; i2c_mark_adapter_suspended(&i2c_dev->adapter); if (!pm_runtime_status_suspended(dev)) err = tegra_i2c_runtime_suspend(dev); return err; } static int __maybe_unused tegra_i2c_resume(struct device *dev) { struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); int err; /* * We need to ensure that clocks are enabled so that registers can be * restored in tegra_i2c_init(). */ err = tegra_i2c_runtime_resume(dev); if (err) return err; err = tegra_i2c_init(i2c_dev, false); if (err) return err; /* * In case we are runtime suspended, disable clocks again so that we * don't unbalance the clock reference counts during the next runtime * resume transition. */ if (pm_runtime_status_suspended(dev)) { err = tegra_i2c_runtime_suspend(dev); if (err) return err; } i2c_mark_adapter_resumed(&i2c_dev->adapter); return 0; } static const struct dev_pm_ops tegra_i2c_pm = { SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume) SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume, NULL) }; static struct platform_driver tegra_i2c_driver = { .probe = tegra_i2c_probe, .remove = tegra_i2c_remove, .driver = { .name = "tegra-i2c", .of_match_table = tegra_i2c_of_match, .pm = &tegra_i2c_pm, }, }; module_platform_driver(tegra_i2c_driver); MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver"); MODULE_AUTHOR("Colin Cross"); MODULE_LICENSE("GPL v2");
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