| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Fabrice Gasnier | 9407 | 97.98% | 25 | 86.21% |
| Olivier Moysan | 124 | 1.29% | 1 | 3.45% |
| Peter Ujfalusi | 50 | 0.52% | 1 | 3.45% |
| Linus Torvalds | 18 | 0.19% | 1 | 3.45% |
| Benjamin Gaignard | 2 | 0.02% | 1 | 3.45% |
| Total | 9601 | 29 |
// SPDX-License-Identifier: GPL-2.0 /* * This file is part of STM32 ADC driver * * Copyright (C) 2016, STMicroelectronics - All Rights Reserved * Author: Fabrice Gasnier <fabrice.gasnier@st.com>. */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/iio/iio.h> #include <linux/iio/buffer.h> #include <linux/iio/timer/stm32-lptim-trigger.h> #include <linux/iio/timer/stm32-timer-trigger.h> #include <linux/iio/trigger.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/of.h> #include <linux/of_device.h> #include "stm32-adc-core.h" /* Number of linear calibration shadow registers / LINCALRDYW control bits */ #define STM32H7_LINCALFACT_NUM 6 /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */ #define STM32H7_BOOST_CLKRATE 20000000UL #define STM32_ADC_CH_MAX 20 /* max number of channels */ #define STM32_ADC_CH_SZ 10 /* max channel name size */ #define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */ #define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */ #define STM32_ADC_TIMEOUT_US 100000 #define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000)) #define STM32_ADC_HW_STOP_DELAY_MS 100 #define STM32_DMA_BUFFER_SIZE PAGE_SIZE /* External trigger enable */ enum stm32_adc_exten { STM32_EXTEN_SWTRIG, STM32_EXTEN_HWTRIG_RISING_EDGE, STM32_EXTEN_HWTRIG_FALLING_EDGE, STM32_EXTEN_HWTRIG_BOTH_EDGES, }; /* extsel - trigger mux selection value */ enum stm32_adc_extsel { STM32_EXT0, STM32_EXT1, STM32_EXT2, STM32_EXT3, STM32_EXT4, STM32_EXT5, STM32_EXT6, STM32_EXT7, STM32_EXT8, STM32_EXT9, STM32_EXT10, STM32_EXT11, STM32_EXT12, STM32_EXT13, STM32_EXT14, STM32_EXT15, STM32_EXT16, STM32_EXT17, STM32_EXT18, STM32_EXT19, STM32_EXT20, }; /** * struct stm32_adc_trig_info - ADC trigger info * @name: name of the trigger, corresponding to its source * @extsel: trigger selection */ struct stm32_adc_trig_info { const char *name; enum stm32_adc_extsel extsel; }; /** * struct stm32_adc_calib - optional adc calibration data * @calfact_s: Calibration offset for single ended channels * @calfact_d: Calibration offset in differential * @lincalfact: Linearity calibration factor * @calibrated: Indicates calibration status */ struct stm32_adc_calib { u32 calfact_s; u32 calfact_d; u32 lincalfact[STM32H7_LINCALFACT_NUM]; bool calibrated; }; /** * struct stm32_adc_regs - stm32 ADC misc registers & bitfield desc * @reg: register offset * @mask: bitfield mask * @shift: left shift */ struct stm32_adc_regs { int reg; int mask; int shift; }; /** * struct stm32_adc_regspec - stm32 registers definition * @dr: data register offset * @ier_eoc: interrupt enable register & eocie bitfield * @ier_ovr: interrupt enable register & overrun bitfield * @isr_eoc: interrupt status register & eoc bitfield * @isr_ovr: interrupt status register & overrun bitfield * @sqr: reference to sequence registers array * @exten: trigger control register & bitfield * @extsel: trigger selection register & bitfield * @res: resolution selection register & bitfield * @smpr: smpr1 & smpr2 registers offset array * @smp_bits: smpr1 & smpr2 index and bitfields */ struct stm32_adc_regspec { const u32 dr; const struct stm32_adc_regs ier_eoc; const struct stm32_adc_regs ier_ovr; const struct stm32_adc_regs isr_eoc; const struct stm32_adc_regs isr_ovr; const struct stm32_adc_regs *sqr; const struct stm32_adc_regs exten; const struct stm32_adc_regs extsel; const struct stm32_adc_regs res; const u32 smpr[2]; const struct stm32_adc_regs *smp_bits; }; struct stm32_adc; /** * struct stm32_adc_cfg - stm32 compatible configuration data * @regs: registers descriptions * @adc_info: per instance input channels definitions * @trigs: external trigger sources * @clk_required: clock is required * @has_vregready: vregready status flag presence * @prepare: optional prepare routine (power-up, enable) * @start_conv: routine to start conversions * @stop_conv: routine to stop conversions * @unprepare: optional unprepare routine (disable, power-down) * @smp_cycles: programmable sampling time (ADC clock cycles) */ struct stm32_adc_cfg { const struct stm32_adc_regspec *regs; const struct stm32_adc_info *adc_info; struct stm32_adc_trig_info *trigs; bool clk_required; bool has_vregready; int (*prepare)(struct stm32_adc *); void (*start_conv)(struct stm32_adc *, bool dma); void (*stop_conv)(struct stm32_adc *); void (*unprepare)(struct stm32_adc *); const unsigned int *smp_cycles; }; /** * struct stm32_adc - private data of each ADC IIO instance * @common: reference to ADC block common data * @offset: ADC instance register offset in ADC block * @cfg: compatible configuration data * @completion: end of single conversion completion * @buffer: data buffer * @clk: clock for this adc instance * @irq: interrupt for this adc instance * @lock: spinlock * @bufi: data buffer index * @num_conv: expected number of scan conversions * @res: data resolution (e.g. RES bitfield value) * @trigger_polarity: external trigger polarity (e.g. exten) * @dma_chan: dma channel * @rx_buf: dma rx buffer cpu address * @rx_dma_buf: dma rx buffer bus address * @rx_buf_sz: dma rx buffer size * @difsel: bitmask to set single-ended/differential channel * @pcsel: bitmask to preselect channels on some devices * @smpr_val: sampling time settings (e.g. smpr1 / smpr2) * @cal: optional calibration data on some devices * @chan_name: channel name array */ struct stm32_adc { struct stm32_adc_common *common; u32 offset; const struct stm32_adc_cfg *cfg; struct completion completion; u16 buffer[STM32_ADC_MAX_SQ]; struct clk *clk; int irq; spinlock_t lock; /* interrupt lock */ unsigned int bufi; unsigned int num_conv; u32 res; u32 trigger_polarity; struct dma_chan *dma_chan; u8 *rx_buf; dma_addr_t rx_dma_buf; unsigned int rx_buf_sz; u32 difsel; u32 pcsel; u32 smpr_val[2]; struct stm32_adc_calib cal; char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ]; }; struct stm32_adc_diff_channel { u32 vinp; u32 vinn; }; /** * struct stm32_adc_info - stm32 ADC, per instance config data * @max_channels: Number of channels * @resolutions: available resolutions * @num_res: number of available resolutions */ struct stm32_adc_info { int max_channels; const unsigned int *resolutions; const unsigned int num_res; }; static const unsigned int stm32f4_adc_resolutions[] = { /* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */ 12, 10, 8, 6, }; /* stm32f4 can have up to 16 channels */ static const struct stm32_adc_info stm32f4_adc_info = { .max_channels = 16, .resolutions = stm32f4_adc_resolutions, .num_res = ARRAY_SIZE(stm32f4_adc_resolutions), }; static const unsigned int stm32h7_adc_resolutions[] = { /* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */ 16, 14, 12, 10, 8, }; /* stm32h7 can have up to 20 channels */ static const struct stm32_adc_info stm32h7_adc_info = { .max_channels = STM32_ADC_CH_MAX, .resolutions = stm32h7_adc_resolutions, .num_res = ARRAY_SIZE(stm32h7_adc_resolutions), }; /* * stm32f4_sq - describe regular sequence registers * - L: sequence len (register & bit field) * - SQ1..SQ16: sequence entries (register & bit field) */ static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = { /* L: len bit field description to be kept as first element */ { STM32F4_ADC_SQR1, GENMASK(23, 20), 20 }, /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */ { STM32F4_ADC_SQR3, GENMASK(4, 0), 0 }, { STM32F4_ADC_SQR3, GENMASK(9, 5), 5 }, { STM32F4_ADC_SQR3, GENMASK(14, 10), 10 }, { STM32F4_ADC_SQR3, GENMASK(19, 15), 15 }, { STM32F4_ADC_SQR3, GENMASK(24, 20), 20 }, { STM32F4_ADC_SQR3, GENMASK(29, 25), 25 }, { STM32F4_ADC_SQR2, GENMASK(4, 0), 0 }, { STM32F4_ADC_SQR2, GENMASK(9, 5), 5 }, { STM32F4_ADC_SQR2, GENMASK(14, 10), 10 }, { STM32F4_ADC_SQR2, GENMASK(19, 15), 15 }, { STM32F4_ADC_SQR2, GENMASK(24, 20), 20 }, { STM32F4_ADC_SQR2, GENMASK(29, 25), 25 }, { STM32F4_ADC_SQR1, GENMASK(4, 0), 0 }, { STM32F4_ADC_SQR1, GENMASK(9, 5), 5 }, { STM32F4_ADC_SQR1, GENMASK(14, 10), 10 }, { STM32F4_ADC_SQR1, GENMASK(19, 15), 15 }, }; /* STM32F4 external trigger sources for all instances */ static struct stm32_adc_trig_info stm32f4_adc_trigs[] = { { TIM1_CH1, STM32_EXT0 }, { TIM1_CH2, STM32_EXT1 }, { TIM1_CH3, STM32_EXT2 }, { TIM2_CH2, STM32_EXT3 }, { TIM2_CH3, STM32_EXT4 }, { TIM2_CH4, STM32_EXT5 }, { TIM2_TRGO, STM32_EXT6 }, { TIM3_CH1, STM32_EXT7 }, { TIM3_TRGO, STM32_EXT8 }, { TIM4_CH4, STM32_EXT9 }, { TIM5_CH1, STM32_EXT10 }, { TIM5_CH2, STM32_EXT11 }, { TIM5_CH3, STM32_EXT12 }, { TIM8_CH1, STM32_EXT13 }, { TIM8_TRGO, STM32_EXT14 }, {}, /* sentinel */ }; /* * stm32f4_smp_bits[] - describe sampling time register index & bit fields * Sorted so it can be indexed by channel number. */ static const struct stm32_adc_regs stm32f4_smp_bits[] = { /* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */ { 1, GENMASK(2, 0), 0 }, { 1, GENMASK(5, 3), 3 }, { 1, GENMASK(8, 6), 6 }, { 1, GENMASK(11, 9), 9 }, { 1, GENMASK(14, 12), 12 }, { 1, GENMASK(17, 15), 15 }, { 1, GENMASK(20, 18), 18 }, { 1, GENMASK(23, 21), 21 }, { 1, GENMASK(26, 24), 24 }, { 1, GENMASK(29, 27), 27 }, /* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */ { 0, GENMASK(2, 0), 0 }, { 0, GENMASK(5, 3), 3 }, { 0, GENMASK(8, 6), 6 }, { 0, GENMASK(11, 9), 9 }, { 0, GENMASK(14, 12), 12 }, { 0, GENMASK(17, 15), 15 }, { 0, GENMASK(20, 18), 18 }, { 0, GENMASK(23, 21), 21 }, { 0, GENMASK(26, 24), 24 }, }; /* STM32F4 programmable sampling time (ADC clock cycles) */ static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { 3, 15, 28, 56, 84, 112, 144, 480, }; static const struct stm32_adc_regspec stm32f4_adc_regspec = { .dr = STM32F4_ADC_DR, .ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE }, .ier_ovr = { STM32F4_ADC_CR1, STM32F4_OVRIE }, .isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC }, .isr_ovr = { STM32F4_ADC_SR, STM32F4_OVR }, .sqr = stm32f4_sq, .exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT }, .extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK, STM32F4_EXTSEL_SHIFT }, .res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT }, .smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 }, .smp_bits = stm32f4_smp_bits, }; static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = { /* L: len bit field description to be kept as first element */ { STM32H7_ADC_SQR1, GENMASK(3, 0), 0 }, /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */ { STM32H7_ADC_SQR1, GENMASK(10, 6), 6 }, { STM32H7_ADC_SQR1, GENMASK(16, 12), 12 }, { STM32H7_ADC_SQR1, GENMASK(22, 18), 18 }, { STM32H7_ADC_SQR1, GENMASK(28, 24), 24 }, { STM32H7_ADC_SQR2, GENMASK(4, 0), 0 }, { STM32H7_ADC_SQR2, GENMASK(10, 6), 6 }, { STM32H7_ADC_SQR2, GENMASK(16, 12), 12 }, { STM32H7_ADC_SQR2, GENMASK(22, 18), 18 }, { STM32H7_ADC_SQR2, GENMASK(28, 24), 24 }, { STM32H7_ADC_SQR3, GENMASK(4, 0), 0 }, { STM32H7_ADC_SQR3, GENMASK(10, 6), 6 }, { STM32H7_ADC_SQR3, GENMASK(16, 12), 12 }, { STM32H7_ADC_SQR3, GENMASK(22, 18), 18 }, { STM32H7_ADC_SQR3, GENMASK(28, 24), 24 }, { STM32H7_ADC_SQR4, GENMASK(4, 0), 0 }, { STM32H7_ADC_SQR4, GENMASK(10, 6), 6 }, }; /* STM32H7 external trigger sources for all instances */ static struct stm32_adc_trig_info stm32h7_adc_trigs[] = { { TIM1_CH1, STM32_EXT0 }, { TIM1_CH2, STM32_EXT1 }, { TIM1_CH3, STM32_EXT2 }, { TIM2_CH2, STM32_EXT3 }, { TIM3_TRGO, STM32_EXT4 }, { TIM4_CH4, STM32_EXT5 }, { TIM8_TRGO, STM32_EXT7 }, { TIM8_TRGO2, STM32_EXT8 }, { TIM1_TRGO, STM32_EXT9 }, { TIM1_TRGO2, STM32_EXT10 }, { TIM2_TRGO, STM32_EXT11 }, { TIM4_TRGO, STM32_EXT12 }, { TIM6_TRGO, STM32_EXT13 }, { TIM15_TRGO, STM32_EXT14 }, { TIM3_CH4, STM32_EXT15 }, { LPTIM1_OUT, STM32_EXT18 }, { LPTIM2_OUT, STM32_EXT19 }, { LPTIM3_OUT, STM32_EXT20 }, {}, }; /* * stm32h7_smp_bits - describe sampling time register index & bit fields * Sorted so it can be indexed by channel number. */ static const struct stm32_adc_regs stm32h7_smp_bits[] = { /* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */ { 0, GENMASK(2, 0), 0 }, { 0, GENMASK(5, 3), 3 }, { 0, GENMASK(8, 6), 6 }, { 0, GENMASK(11, 9), 9 }, { 0, GENMASK(14, 12), 12 }, { 0, GENMASK(17, 15), 15 }, { 0, GENMASK(20, 18), 18 }, { 0, GENMASK(23, 21), 21 }, { 0, GENMASK(26, 24), 24 }, { 0, GENMASK(29, 27), 27 }, /* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */ { 1, GENMASK(2, 0), 0 }, { 1, GENMASK(5, 3), 3 }, { 1, GENMASK(8, 6), 6 }, { 1, GENMASK(11, 9), 9 }, { 1, GENMASK(14, 12), 12 }, { 1, GENMASK(17, 15), 15 }, { 1, GENMASK(20, 18), 18 }, { 1, GENMASK(23, 21), 21 }, { 1, GENMASK(26, 24), 24 }, { 1, GENMASK(29, 27), 27 }, }; /* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */ static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { 1, 2, 8, 16, 32, 64, 387, 810, }; static const struct stm32_adc_regspec stm32h7_adc_regspec = { .dr = STM32H7_ADC_DR, .ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE }, .ier_ovr = { STM32H7_ADC_IER, STM32H7_OVRIE }, .isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC }, .isr_ovr = { STM32H7_ADC_ISR, STM32H7_OVR }, .sqr = stm32h7_sq, .exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT }, .extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK, STM32H7_EXTSEL_SHIFT }, .res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT }, .smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 }, .smp_bits = stm32h7_smp_bits, }; /** * STM32 ADC registers access routines * @adc: stm32 adc instance * @reg: reg offset in adc instance * * Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp. * for adc1, adc2 and adc3. */ static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg) { return readl_relaxed(adc->common->base + adc->offset + reg); } #define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr) #define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \ readx_poll_timeout(stm32_adc_readl_addr, reg, val, \ cond, sleep_us, timeout_us) static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg) { return readw_relaxed(adc->common->base + adc->offset + reg); } static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val) { writel_relaxed(val, adc->common->base + adc->offset + reg); } static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits) { unsigned long flags; spin_lock_irqsave(&adc->lock, flags); stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits); spin_unlock_irqrestore(&adc->lock, flags); } static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits) { unsigned long flags; spin_lock_irqsave(&adc->lock, flags); stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits); spin_unlock_irqrestore(&adc->lock, flags); } /** * stm32_adc_conv_irq_enable() - Enable end of conversion interrupt * @adc: stm32 adc instance */ static void stm32_adc_conv_irq_enable(struct stm32_adc *adc) { stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg, adc->cfg->regs->ier_eoc.mask); }; /** * stm32_adc_conv_irq_disable() - Disable end of conversion interrupt * @adc: stm32 adc instance */ static void stm32_adc_conv_irq_disable(struct stm32_adc *adc) { stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg, adc->cfg->regs->ier_eoc.mask); } static void stm32_adc_ovr_irq_enable(struct stm32_adc *adc) { stm32_adc_set_bits(adc, adc->cfg->regs->ier_ovr.reg, adc->cfg->regs->ier_ovr.mask); } static void stm32_adc_ovr_irq_disable(struct stm32_adc *adc) { stm32_adc_clr_bits(adc, adc->cfg->regs->ier_ovr.reg, adc->cfg->regs->ier_ovr.mask); } static void stm32_adc_set_res(struct stm32_adc *adc) { const struct stm32_adc_regs *res = &adc->cfg->regs->res; u32 val; val = stm32_adc_readl(adc, res->reg); val = (val & ~res->mask) | (adc->res << res->shift); stm32_adc_writel(adc, res->reg, val); } static int stm32_adc_hw_stop(struct device *dev) { struct stm32_adc *adc = dev_get_drvdata(dev); if (adc->cfg->unprepare) adc->cfg->unprepare(adc); if (adc->clk) clk_disable_unprepare(adc->clk); return 0; } static int stm32_adc_hw_start(struct device *dev) { struct stm32_adc *adc = dev_get_drvdata(dev); int ret; if (adc->clk) { ret = clk_prepare_enable(adc->clk); if (ret) return ret; } stm32_adc_set_res(adc); if (adc->cfg->prepare) { ret = adc->cfg->prepare(adc); if (ret) goto err_clk_dis; } return 0; err_clk_dis: if (adc->clk) clk_disable_unprepare(adc->clk); return ret; } /** * stm32f4_adc_start_conv() - Start conversions for regular channels. * @adc: stm32 adc instance * @dma: use dma to transfer conversion result * * Start conversions for regular channels. * Also take care of normal or DMA mode. Circular DMA may be used for regular * conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct * DR read instead (e.g. read_raw, or triggered buffer mode without DMA). */ static void stm32f4_adc_start_conv(struct stm32_adc *adc, bool dma) { stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN); if (dma) stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_DMA | STM32F4_DDS); stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON); /* Wait for Power-up time (tSTAB from datasheet) */ usleep_range(2, 3); /* Software start ? (e.g. trigger detection disabled ?) */ if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK)) stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART); } static void stm32f4_adc_stop_conv(struct stm32_adc *adc) { stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK); stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT); stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN); stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_ADON | STM32F4_DMA | STM32F4_DDS); } static void stm32h7_adc_start_conv(struct stm32_adc *adc, bool dma) { enum stm32h7_adc_dmngt dmngt; unsigned long flags; u32 val; if (dma) dmngt = STM32H7_DMNGT_DMA_CIRC; else dmngt = STM32H7_DMNGT_DR_ONLY; spin_lock_irqsave(&adc->lock, flags); val = stm32_adc_readl(adc, STM32H7_ADC_CFGR); val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT); stm32_adc_writel(adc, STM32H7_ADC_CFGR, val); spin_unlock_irqrestore(&adc->lock, flags); stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART); } static void stm32h7_adc_stop_conv(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; u32 val; stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & (STM32H7_ADSTART)), 100, STM32_ADC_TIMEOUT_US); if (ret) dev_warn(&indio_dev->dev, "stop failed\n"); stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK); } static int stm32h7_adc_exit_pwr_down(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; u32 val; /* Exit deep power down, then enable ADC voltage regulator */ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN); if (adc->common->rate > STM32H7_BOOST_CLKRATE) stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST); /* Wait for startup time */ if (!adc->cfg->has_vregready) { usleep_range(10, 20); return 0; } ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val, val & STM32MP1_VREGREADY, 100, STM32_ADC_TIMEOUT_US); if (ret) { stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); dev_err(&indio_dev->dev, "Failed to exit power down\n"); } return ret; } static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc) { stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST); /* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); } static int stm32h7_adc_enable(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; u32 val; stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN); /* Poll for ADRDY to be set (after adc startup time) */ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val, val & STM32H7_ADRDY, 100, STM32_ADC_TIMEOUT_US); if (ret) { stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS); dev_err(&indio_dev->dev, "Failed to enable ADC\n"); } else { /* Clear ADRDY by writing one */ stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY); } return ret; } static void stm32h7_adc_disable(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; u32 val; /* Disable ADC and wait until it's effectively disabled */ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & STM32H7_ADEN), 100, STM32_ADC_TIMEOUT_US); if (ret) dev_warn(&indio_dev->dev, "Failed to disable\n"); } /** * stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result * @adc: stm32 adc instance * Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are writable */ static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int i, ret; u32 lincalrdyw_mask, val; /* Read linearity calibration */ lincalrdyw_mask = STM32H7_LINCALRDYW6; for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) { /* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); /* Poll: wait calib data to be ready in CALFACT2 register */ ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & lincalrdyw_mask), 100, STM32_ADC_TIMEOUT_US); if (ret) { dev_err(&indio_dev->dev, "Failed to read calfact\n"); return ret; } val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2); adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK); adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT; lincalrdyw_mask >>= 1; } /* Read offset calibration */ val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT); adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK); adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT; adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK); adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT; adc->cal.calibrated = true; return 0; } /** * stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result * @adc: stm32 adc instance * Note: ADC must be enabled, with no on-going conversions. */ static int stm32h7_adc_restore_selfcalib(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int i, ret; u32 lincalrdyw_mask, val; val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) | (adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT); stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val); lincalrdyw_mask = STM32H7_LINCALRDYW6; for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) { /* * Write saved calibration data to shadow registers: * Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger * data write. Then poll to wait for complete transfer. */ val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT; stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val); stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, val & lincalrdyw_mask, 100, STM32_ADC_TIMEOUT_US); if (ret) { dev_err(&indio_dev->dev, "Failed to write calfact\n"); return ret; } /* * Read back calibration data, has two effects: * - It ensures bits LINCALRDYW[6..1] are kept cleared * for next time calibration needs to be restored. * - BTW, bit clear triggers a read, then check data has been * correctly written. */ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & lincalrdyw_mask), 100, STM32_ADC_TIMEOUT_US); if (ret) { dev_err(&indio_dev->dev, "Failed to read calfact\n"); return ret; } val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2); if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) { dev_err(&indio_dev->dev, "calfact not consistent\n"); return -EIO; } lincalrdyw_mask >>= 1; } return 0; } /** * Fixed timeout value for ADC calibration. * worst cases: * - low clock frequency * - maximum prescalers * Calibration requires: * - 131,072 ADC clock cycle for the linear calibration * - 20 ADC clock cycle for the offset calibration * * Set to 100ms for now */ #define STM32H7_ADC_CALIB_TIMEOUT_US 100000 /** * stm32h7_adc_selfcalib() - Procedure to calibrate ADC * @adc: stm32 adc instance * Note: Must be called once ADC is out of power down. */ static int stm32h7_adc_selfcalib(struct stm32_adc *adc) { struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; u32 val; if (adc->cal.calibrated) return true; /* * Select calibration mode: * - Offset calibration for single ended inputs * - No linearity calibration (do it later, before reading it) */ stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF); stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN); /* Start calibration, then wait for completion */ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & STM32H7_ADCAL), 100, STM32H7_ADC_CALIB_TIMEOUT_US); if (ret) { dev_err(&indio_dev->dev, "calibration failed\n"); goto out; } /* * Select calibration mode, then start calibration: * - Offset calibration for differential input * - Linearity calibration (needs to be done only once for single/diff) * will run simultaneously with offset calibration. */ stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF | STM32H7_ADCALLIN); stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL); ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, !(val & STM32H7_ADCAL), 100, STM32H7_ADC_CALIB_TIMEOUT_US); if (ret) { dev_err(&indio_dev->dev, "calibration failed\n"); goto out; } out: stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF | STM32H7_ADCALLIN); return ret; } /** * stm32h7_adc_prepare() - Leave power down mode to enable ADC. * @adc: stm32 adc instance * Leave power down mode. * Configure channels as single ended or differential before enabling ADC. * Enable ADC. * Restore calibration data. * Pre-select channels that may be used in PCSEL (required by input MUX / IO): * - Only one input is selected for single ended (e.g. 'vinp') * - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn') */ static int stm32h7_adc_prepare(struct stm32_adc *adc) { int calib, ret; ret = stm32h7_adc_exit_pwr_down(adc); if (ret) return ret; ret = stm32h7_adc_selfcalib(adc); if (ret < 0) goto pwr_dwn; calib = ret; stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel); ret = stm32h7_adc_enable(adc); if (ret) goto pwr_dwn; /* Either restore or read calibration result for future reference */ if (calib) ret = stm32h7_adc_restore_selfcalib(adc); else ret = stm32h7_adc_read_selfcalib(adc); if (ret) goto disable; stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel); return 0; disable: stm32h7_adc_disable(adc); pwr_dwn: stm32h7_adc_enter_pwr_down(adc); return ret; } static void stm32h7_adc_unprepare(struct stm32_adc *adc) { stm32h7_adc_disable(adc); stm32h7_adc_enter_pwr_down(adc); } /** * stm32_adc_conf_scan_seq() - Build regular channels scan sequence * @indio_dev: IIO device * @scan_mask: channels to be converted * * Conversion sequence : * Apply sampling time settings for all channels. * Configure ADC scan sequence based on selected channels in scan_mask. * Add channels to SQR registers, from scan_mask LSB to MSB, then * program sequence len. */ static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev, const unsigned long *scan_mask) { struct stm32_adc *adc = iio_priv(indio_dev); const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr; const struct iio_chan_spec *chan; u32 val, bit; int i = 0; /* Apply sampling time settings */ stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]); stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]); for_each_set_bit(bit, scan_mask, indio_dev->masklength) { chan = indio_dev->channels + bit; /* * Assign one channel per SQ entry in regular * sequence, starting with SQ1. */ i++; if (i > STM32_ADC_MAX_SQ) return -EINVAL; dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n", __func__, chan->channel, i); val = stm32_adc_readl(adc, sqr[i].reg); val &= ~sqr[i].mask; val |= chan->channel << sqr[i].shift; stm32_adc_writel(adc, sqr[i].reg, val); } if (!i) return -EINVAL; /* Sequence len */ val = stm32_adc_readl(adc, sqr[0].reg); val &= ~sqr[0].mask; val |= ((i - 1) << sqr[0].shift); stm32_adc_writel(adc, sqr[0].reg, val); return 0; } /** * stm32_adc_get_trig_extsel() - Get external trigger selection * @indio_dev: IIO device structure * @trig: trigger * * Returns trigger extsel value, if trig matches, -EINVAL otherwise. */ static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev, struct iio_trigger *trig) { struct stm32_adc *adc = iio_priv(indio_dev); int i; /* lookup triggers registered by stm32 timer trigger driver */ for (i = 0; adc->cfg->trigs[i].name; i++) { /** * Checking both stm32 timer trigger type and trig name * should be safe against arbitrary trigger names. */ if ((is_stm32_timer_trigger(trig) || is_stm32_lptim_trigger(trig)) && !strcmp(adc->cfg->trigs[i].name, trig->name)) { return adc->cfg->trigs[i].extsel; } } return -EINVAL; } /** * stm32_adc_set_trig() - Set a regular trigger * @indio_dev: IIO device * @trig: IIO trigger * * Set trigger source/polarity (e.g. SW, or HW with polarity) : * - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw) * - if HW trigger enabled, set source & polarity */ static int stm32_adc_set_trig(struct iio_dev *indio_dev, struct iio_trigger *trig) { struct stm32_adc *adc = iio_priv(indio_dev); u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG; unsigned long flags; int ret; if (trig) { ret = stm32_adc_get_trig_extsel(indio_dev, trig); if (ret < 0) return ret; /* set trigger source and polarity (default to rising edge) */ extsel = ret; exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE; } spin_lock_irqsave(&adc->lock, flags); val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg); val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask); val |= exten << adc->cfg->regs->exten.shift; val |= extsel << adc->cfg->regs->extsel.shift; stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val); spin_unlock_irqrestore(&adc->lock, flags); return 0; } static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, unsigned int type) { struct stm32_adc *adc = iio_priv(indio_dev); adc->trigger_polarity = type; return 0; } static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev, const struct iio_chan_spec *chan) { struct stm32_adc *adc = iio_priv(indio_dev); return adc->trigger_polarity; } static const char * const stm32_trig_pol_items[] = { "rising-edge", "falling-edge", "both-edges", }; static const struct iio_enum stm32_adc_trig_pol = { .items = stm32_trig_pol_items, .num_items = ARRAY_SIZE(stm32_trig_pol_items), .get = stm32_adc_get_trig_pol, .set = stm32_adc_set_trig_pol, }; /** * stm32_adc_single_conv() - Performs a single conversion * @indio_dev: IIO device * @chan: IIO channel * @res: conversion result * * The function performs a single conversion on a given channel: * - Apply sampling time settings * - Program sequencer with one channel (e.g. in SQ1 with len = 1) * - Use SW trigger * - Start conversion, then wait for interrupt completion. */ static int stm32_adc_single_conv(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *res) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; const struct stm32_adc_regspec *regs = adc->cfg->regs; long timeout; u32 val; int ret; reinit_completion(&adc->completion); adc->bufi = 0; ret = pm_runtime_get_sync(dev); if (ret < 0) { pm_runtime_put_noidle(dev); return ret; } /* Apply sampling time settings */ stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]); stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]); /* Program chan number in regular sequence (SQ1) */ val = stm32_adc_readl(adc, regs->sqr[1].reg); val &= ~regs->sqr[1].mask; val |= chan->channel << regs->sqr[1].shift; stm32_adc_writel(adc, regs->sqr[1].reg, val); /* Set regular sequence len (0 for 1 conversion) */ stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask); /* Trigger detection disabled (conversion can be launched in SW) */ stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask); stm32_adc_conv_irq_enable(adc); adc->cfg->start_conv(adc, false); timeout = wait_for_completion_interruptible_timeout( &adc->completion, STM32_ADC_TIMEOUT); if (timeout == 0) { ret = -ETIMEDOUT; } else if (timeout < 0) { ret = timeout; } else { *res = adc->buffer[0]; ret = IIO_VAL_INT; } adc->cfg->stop_conv(adc); stm32_adc_conv_irq_disable(adc); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return ret; } static int stm32_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct stm32_adc *adc = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; if (chan->type == IIO_VOLTAGE) ret = stm32_adc_single_conv(indio_dev, chan, val); else ret = -EINVAL; iio_device_release_direct_mode(indio_dev); return ret; case IIO_CHAN_INFO_SCALE: if (chan->differential) { *val = adc->common->vref_mv * 2; *val2 = chan->scan_type.realbits; } else { *val = adc->common->vref_mv; *val2 = chan->scan_type.realbits; } return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: if (chan->differential) /* ADC_full_scale / 2 */ *val = -((1 << chan->scan_type.realbits) / 2); else *val = 0; return IIO_VAL_INT; default: return -EINVAL; } } static irqreturn_t stm32_adc_threaded_isr(int irq, void *data) { struct stm32_adc *adc = data; struct iio_dev *indio_dev = iio_priv_to_dev(adc); const struct stm32_adc_regspec *regs = adc->cfg->regs; u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); if (status & regs->isr_ovr.mask) dev_err(&indio_dev->dev, "Overrun, stopping: restart needed\n"); return IRQ_HANDLED; } static irqreturn_t stm32_adc_isr(int irq, void *data) { struct stm32_adc *adc = data; struct iio_dev *indio_dev = iio_priv_to_dev(adc); const struct stm32_adc_regspec *regs = adc->cfg->regs; u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); if (status & regs->isr_ovr.mask) { /* * Overrun occurred on regular conversions: data for wrong * channel may be read. Unconditionally disable interrupts * to stop processing data and print error message. * Restarting the capture can be done by disabling, then * re-enabling it (e.g. write 0, then 1 to buffer/enable). */ stm32_adc_ovr_irq_disable(adc); stm32_adc_conv_irq_disable(adc); return IRQ_WAKE_THREAD; } if (status & regs->isr_eoc.mask) { /* Reading DR also clears EOC status flag */ adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr); if (iio_buffer_enabled(indio_dev)) { adc->bufi++; if (adc->bufi >= adc->num_conv) { stm32_adc_conv_irq_disable(adc); iio_trigger_poll(indio_dev->trig); } } else { complete(&adc->completion); } return IRQ_HANDLED; } return IRQ_NONE; } /** * stm32_adc_validate_trigger() - validate trigger for stm32 adc * @indio_dev: IIO device * @trig: new trigger * * Returns: 0 if trig matches one of the triggers registered by stm32 adc * driver, -EINVAL otherwise. */ static int stm32_adc_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) { return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0; } static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) { struct stm32_adc *adc = iio_priv(indio_dev); unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2; unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE; /* * dma cyclic transfers are used, buffer is split into two periods. * There should be : * - always one buffer (period) dma is working on * - one buffer (period) driver can push with iio_trigger_poll(). */ watermark = min(watermark, val * (unsigned)(sizeof(u16))); adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv); return 0; } static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; int ret; ret = pm_runtime_get_sync(dev); if (ret < 0) { pm_runtime_put_noidle(dev); return ret; } adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength); ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return ret; } static int stm32_adc_of_xlate(struct iio_dev *indio_dev, const struct of_phandle_args *iiospec) { int i; for (i = 0; i < indio_dev->num_channels; i++) if (indio_dev->channels[i].channel == iiospec->args[0]) return i; return -EINVAL; } /** * stm32_adc_debugfs_reg_access - read or write register value * @indio_dev: IIO device structure * @reg: register offset * @writeval: value to write * @readval: value to read * * To read a value from an ADC register: * echo [ADC reg offset] > direct_reg_access * cat direct_reg_access * * To write a value in a ADC register: * echo [ADC_reg_offset] [value] > direct_reg_access */ static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev, unsigned reg, unsigned writeval, unsigned *readval) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; int ret; ret = pm_runtime_get_sync(dev); if (ret < 0) { pm_runtime_put_noidle(dev); return ret; } if (!readval) stm32_adc_writel(adc, reg, writeval); else *readval = stm32_adc_readl(adc, reg); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return 0; } static const struct iio_info stm32_adc_iio_info = { .read_raw = stm32_adc_read_raw, .validate_trigger = stm32_adc_validate_trigger, .hwfifo_set_watermark = stm32_adc_set_watermark, .update_scan_mode = stm32_adc_update_scan_mode, .debugfs_reg_access = stm32_adc_debugfs_reg_access, .of_xlate = stm32_adc_of_xlate, }; static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc) { struct dma_tx_state state; enum dma_status status; status = dmaengine_tx_status(adc->dma_chan, adc->dma_chan->cookie, &state); if (status == DMA_IN_PROGRESS) { /* Residue is size in bytes from end of buffer */ unsigned int i = adc->rx_buf_sz - state.residue; unsigned int size; /* Return available bytes */ if (i >= adc->bufi) size = i - adc->bufi; else size = adc->rx_buf_sz + i - adc->bufi; return size; } return 0; } static void stm32_adc_dma_buffer_done(void *data) { struct iio_dev *indio_dev = data; struct stm32_adc *adc = iio_priv(indio_dev); int residue = stm32_adc_dma_residue(adc); /* * In DMA mode the trigger services of IIO are not used * (e.g. no call to iio_trigger_poll). * Calling irq handler associated to the hardware trigger is not * relevant as the conversions have already been done. Data * transfers are performed directly in DMA callback instead. * This implementation avoids to call trigger irq handler that * may sleep, in an atomic context (DMA irq handler context). */ dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi); while (residue >= indio_dev->scan_bytes) { u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi]; iio_push_to_buffers(indio_dev, buffer); residue -= indio_dev->scan_bytes; adc->bufi += indio_dev->scan_bytes; if (adc->bufi >= adc->rx_buf_sz) adc->bufi = 0; } } static int stm32_adc_dma_start(struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct dma_async_tx_descriptor *desc; dma_cookie_t cookie; int ret; if (!adc->dma_chan) return 0; dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__, adc->rx_buf_sz, adc->rx_buf_sz / 2); /* Prepare a DMA cyclic transaction */ desc = dmaengine_prep_dma_cyclic(adc->dma_chan, adc->rx_dma_buf, adc->rx_buf_sz, adc->rx_buf_sz / 2, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) return -EBUSY; desc->callback = stm32_adc_dma_buffer_done; desc->callback_param = indio_dev; cookie = dmaengine_submit(desc); ret = dma_submit_error(cookie); if (ret) { dmaengine_terminate_sync(adc->dma_chan); return ret; } /* Issue pending DMA requests */ dma_async_issue_pending(adc->dma_chan); return 0; } static int __stm32_adc_buffer_postenable(struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; int ret; ret = pm_runtime_get_sync(dev); if (ret < 0) { pm_runtime_put_noidle(dev); return ret; } ret = stm32_adc_set_trig(indio_dev, indio_dev->trig); if (ret) { dev_err(&indio_dev->dev, "Can't set trigger\n"); goto err_pm_put; } ret = stm32_adc_dma_start(indio_dev); if (ret) { dev_err(&indio_dev->dev, "Can't start dma\n"); goto err_clr_trig; } /* Reset adc buffer index */ adc->bufi = 0; stm32_adc_ovr_irq_enable(adc); if (!adc->dma_chan) stm32_adc_conv_irq_enable(adc); adc->cfg->start_conv(adc, !!adc->dma_chan); return 0; err_clr_trig: stm32_adc_set_trig(indio_dev, NULL); err_pm_put: pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return ret; } static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) { int ret; ret = iio_triggered_buffer_postenable(indio_dev); if (ret < 0) return ret; ret = __stm32_adc_buffer_postenable(indio_dev); if (ret < 0) iio_triggered_buffer_predisable(indio_dev); return ret; } static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; adc->cfg->stop_conv(adc); if (!adc->dma_chan) stm32_adc_conv_irq_disable(adc); stm32_adc_ovr_irq_disable(adc); if (adc->dma_chan) dmaengine_terminate_sync(adc->dma_chan); if (stm32_adc_set_trig(indio_dev, NULL)) dev_err(&indio_dev->dev, "Can't clear trigger\n"); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); } static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev) { int ret; __stm32_adc_buffer_predisable(indio_dev); ret = iio_triggered_buffer_predisable(indio_dev); if (ret < 0) dev_err(&indio_dev->dev, "predisable failed\n"); return ret; } static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = { .postenable = &stm32_adc_buffer_postenable, .predisable = &stm32_adc_buffer_predisable, }; static irqreturn_t stm32_adc_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct stm32_adc *adc = iio_priv(indio_dev); dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi); if (!adc->dma_chan) { /* reset buffer index */ adc->bufi = 0; iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer, pf->timestamp); } else { int residue = stm32_adc_dma_residue(adc); while (residue >= indio_dev->scan_bytes) { u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi]; iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp); residue -= indio_dev->scan_bytes; adc->bufi += indio_dev->scan_bytes; if (adc->bufi >= adc->rx_buf_sz) adc->bufi = 0; } } iio_trigger_notify_done(indio_dev->trig); /* re-enable eoc irq */ if (!adc->dma_chan) stm32_adc_conv_irq_enable(adc); return IRQ_HANDLED; } static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = { IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol), { .name = "trigger_polarity_available", .shared = IIO_SHARED_BY_ALL, .read = iio_enum_available_read, .private = (uintptr_t)&stm32_adc_trig_pol, }, {}, }; static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev) { struct device_node *node = indio_dev->dev.of_node; struct stm32_adc *adc = iio_priv(indio_dev); unsigned int i; u32 res; if (of_property_read_u32(node, "assigned-resolution-bits", &res)) res = adc->cfg->adc_info->resolutions[0]; for (i = 0; i < adc->cfg->adc_info->num_res; i++) if (res == adc->cfg->adc_info->resolutions[i]) break; if (i >= adc->cfg->adc_info->num_res) { dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res); return -EINVAL; } dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res); adc->res = i; return 0; } static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns) { const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel]; u32 period_ns, shift = smpr->shift, mask = smpr->mask; unsigned int smp, r = smpr->reg; /* Determine sampling time (ADC clock cycles) */ period_ns = NSEC_PER_SEC / adc->common->rate; for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++) if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns) break; if (smp > STM32_ADC_MAX_SMP) smp = STM32_ADC_MAX_SMP; /* pre-build sampling time registers (e.g. smpr1, smpr2) */ adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift); } static void stm32_adc_chan_init_one(struct iio_dev *indio_dev, struct iio_chan_spec *chan, u32 vinp, u32 vinn, int scan_index, bool differential) { struct stm32_adc *adc = iio_priv(indio_dev); char *name = adc->chan_name[vinp]; chan->type = IIO_VOLTAGE; chan->channel = vinp; if (differential) { chan->differential = 1; chan->channel2 = vinn; snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn); } else { snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp); } chan->datasheet_name = name; chan->scan_index = scan_index; chan->indexed = 1; chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET); chan->scan_type.sign = 'u'; chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res]; chan->scan_type.storagebits = 16; chan->ext_info = stm32_adc_ext_info; /* pre-build selected channels mask */ adc->pcsel |= BIT(chan->channel); if (differential) { /* pre-build diff channels mask */ adc->difsel |= BIT(chan->channel); /* Also add negative input to pre-selected channels */ adc->pcsel |= BIT(chan->channel2); } } static int stm32_adc_chan_of_init(struct iio_dev *indio_dev) { struct device_node *node = indio_dev->dev.of_node; struct stm32_adc *adc = iio_priv(indio_dev); const struct stm32_adc_info *adc_info = adc->cfg->adc_info; struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX]; struct property *prop; const __be32 *cur; struct iio_chan_spec *channels; int scan_index = 0, num_channels = 0, num_diff = 0, ret, i; u32 val, smp = 0; ret = of_property_count_u32_elems(node, "st,adc-channels"); if (ret > adc_info->max_channels) { dev_err(&indio_dev->dev, "Bad st,adc-channels?\n"); return -EINVAL; } else if (ret > 0) { num_channels += ret; } ret = of_property_count_elems_of_size(node, "st,adc-diff-channels", sizeof(*diff)); if (ret > adc_info->max_channels) { dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n"); return -EINVAL; } else if (ret > 0) { int size = ret * sizeof(*diff) / sizeof(u32); num_diff = ret; num_channels += ret; ret = of_property_read_u32_array(node, "st,adc-diff-channels", (u32 *)diff, size); if (ret) return ret; } if (!num_channels) { dev_err(&indio_dev->dev, "No channels configured\n"); return -ENODATA; } /* Optional sample time is provided either for each, or all channels */ ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs"); if (ret > 1 && ret != num_channels) { dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n"); return -EINVAL; } channels = devm_kcalloc(&indio_dev->dev, num_channels, sizeof(struct iio_chan_spec), GFP_KERNEL); if (!channels) return -ENOMEM; of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) { if (val >= adc_info->max_channels) { dev_err(&indio_dev->dev, "Invalid channel %d\n", val); return -EINVAL; } /* Channel can't be configured both as single-ended & diff */ for (i = 0; i < num_diff; i++) { if (val == diff[i].vinp) { dev_err(&indio_dev->dev, "channel %d miss-configured\n", val); return -EINVAL; } } stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val, 0, scan_index, false); scan_index++; } for (i = 0; i < num_diff; i++) { if (diff[i].vinp >= adc_info->max_channels || diff[i].vinn >= adc_info->max_channels) { dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n", diff[i].vinp, diff[i].vinn); return -EINVAL; } stm32_adc_chan_init_one(indio_dev, &channels[scan_index], diff[i].vinp, diff[i].vinn, scan_index, true); scan_index++; } for (i = 0; i < scan_index; i++) { /* * Using of_property_read_u32_index(), smp value will only be * modified if valid u32 value can be decoded. This allows to * get either no value, 1 shared value for all indexes, or one * value per channel. */ of_property_read_u32_index(node, "st,min-sample-time-nsecs", i, &smp); /* Prepare sampling time settings */ stm32_adc_smpr_init(adc, channels[i].channel, smp); } indio_dev->num_channels = scan_index; indio_dev->channels = channels; return 0; } static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct dma_slave_config config; int ret; adc->dma_chan = dma_request_chan(dev, "rx"); if (IS_ERR(adc->dma_chan)) { ret = PTR_ERR(adc->dma_chan); if (ret != -ENODEV) { if (ret != -EPROBE_DEFER) dev_err(dev, "DMA channel request failed with %d\n", ret); return ret; } /* DMA is optional: fall back to IRQ mode */ adc->dma_chan = NULL; return 0; } adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, &adc->rx_dma_buf, GFP_KERNEL); if (!adc->rx_buf) { ret = -ENOMEM; goto err_release; } /* Configure DMA channel to read data register */ memset(&config, 0, sizeof(config)); config.src_addr = (dma_addr_t)adc->common->phys_base; config.src_addr += adc->offset + adc->cfg->regs->dr; config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; ret = dmaengine_slave_config(adc->dma_chan, &config); if (ret) goto err_free; return 0; err_free: dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); err_release: dma_release_channel(adc->dma_chan); return ret; } static int stm32_adc_probe(struct platform_device *pdev) { struct iio_dev *indio_dev; struct device *dev = &pdev->dev; irqreturn_t (*handler)(int irq, void *p) = NULL; struct stm32_adc *adc; int ret; if (!pdev->dev.of_node) return -ENODEV; indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); if (!indio_dev) return -ENOMEM; adc = iio_priv(indio_dev); adc->common = dev_get_drvdata(pdev->dev.parent); spin_lock_init(&adc->lock); init_completion(&adc->completion); adc->cfg = (const struct stm32_adc_cfg *) of_match_device(dev->driver->of_match_table, dev)->data; indio_dev->name = dev_name(&pdev->dev); indio_dev->dev.parent = &pdev->dev; indio_dev->dev.of_node = pdev->dev.of_node; indio_dev->info = &stm32_adc_iio_info; indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED; platform_set_drvdata(pdev, adc); ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset); if (ret != 0) { dev_err(&pdev->dev, "missing reg property\n"); return -EINVAL; } adc->irq = platform_get_irq(pdev, 0); if (adc->irq < 0) return adc->irq; ret = devm_request_threaded_irq(&pdev->dev, adc->irq, stm32_adc_isr, stm32_adc_threaded_isr, 0, pdev->name, adc); if (ret) { dev_err(&pdev->dev, "failed to request IRQ\n"); return ret; } adc->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(adc->clk)) { ret = PTR_ERR(adc->clk); if (ret == -ENOENT && !adc->cfg->clk_required) { adc->clk = NULL; } else { dev_err(&pdev->dev, "Can't get clock\n"); return ret; } } ret = stm32_adc_of_get_resolution(indio_dev); if (ret < 0) return ret; ret = stm32_adc_chan_of_init(indio_dev); if (ret < 0) return ret; ret = stm32_adc_dma_request(dev, indio_dev); if (ret < 0) return ret; if (!adc->dma_chan) handler = &stm32_adc_trigger_handler; ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, handler, &stm32_adc_buffer_setup_ops); if (ret) { dev_err(&pdev->dev, "buffer setup failed\n"); goto err_dma_disable; } /* Get stm32-adc-core PM online */ pm_runtime_get_noresume(dev); pm_runtime_set_active(dev); pm_runtime_set_autosuspend_delay(dev, STM32_ADC_HW_STOP_DELAY_MS); pm_runtime_use_autosuspend(dev); pm_runtime_enable(dev); ret = stm32_adc_hw_start(dev); if (ret) goto err_buffer_cleanup; ret = iio_device_register(indio_dev); if (ret) { dev_err(&pdev->dev, "iio dev register failed\n"); goto err_hw_stop; } pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return 0; err_hw_stop: stm32_adc_hw_stop(dev); err_buffer_cleanup: pm_runtime_disable(dev); pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev); iio_triggered_buffer_cleanup(indio_dev); err_dma_disable: if (adc->dma_chan) { dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); dma_release_channel(adc->dma_chan); } return ret; } static int stm32_adc_remove(struct platform_device *pdev) { struct stm32_adc *adc = platform_get_drvdata(pdev); struct iio_dev *indio_dev = iio_priv_to_dev(adc); pm_runtime_get_sync(&pdev->dev); iio_device_unregister(indio_dev); stm32_adc_hw_stop(&pdev->dev); pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); iio_triggered_buffer_cleanup(indio_dev); if (adc->dma_chan) { dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); dma_release_channel(adc->dma_chan); } return 0; } #if defined(CONFIG_PM_SLEEP) static int stm32_adc_suspend(struct device *dev) { struct stm32_adc *adc = dev_get_drvdata(dev); struct iio_dev *indio_dev = iio_priv_to_dev(adc); if (iio_buffer_enabled(indio_dev)) __stm32_adc_buffer_predisable(indio_dev); return pm_runtime_force_suspend(dev); } static int stm32_adc_resume(struct device *dev) { struct stm32_adc *adc = dev_get_drvdata(dev); struct iio_dev *indio_dev = iio_priv_to_dev(adc); int ret; ret = pm_runtime_force_resume(dev); if (ret < 0) return ret; if (!iio_buffer_enabled(indio_dev)) return 0; ret = stm32_adc_update_scan_mode(indio_dev, indio_dev->active_scan_mask); if (ret < 0) return ret; return __stm32_adc_buffer_postenable(indio_dev); } #endif #if defined(CONFIG_PM) static int stm32_adc_runtime_suspend(struct device *dev) { return stm32_adc_hw_stop(dev); } static int stm32_adc_runtime_resume(struct device *dev) { return stm32_adc_hw_start(dev); } #endif static const struct dev_pm_ops stm32_adc_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(stm32_adc_suspend, stm32_adc_resume) SET_RUNTIME_PM_OPS(stm32_adc_runtime_suspend, stm32_adc_runtime_resume, NULL) }; static const struct stm32_adc_cfg stm32f4_adc_cfg = { .regs = &stm32f4_adc_regspec, .adc_info = &stm32f4_adc_info, .trigs = stm32f4_adc_trigs, .clk_required = true, .start_conv = stm32f4_adc_start_conv, .stop_conv = stm32f4_adc_stop_conv, .smp_cycles = stm32f4_adc_smp_cycles, }; static const struct stm32_adc_cfg stm32h7_adc_cfg = { .regs = &stm32h7_adc_regspec, .adc_info = &stm32h7_adc_info, .trigs = stm32h7_adc_trigs, .start_conv = stm32h7_adc_start_conv, .stop_conv = stm32h7_adc_stop_conv, .prepare = stm32h7_adc_prepare, .unprepare = stm32h7_adc_unprepare, .smp_cycles = stm32h7_adc_smp_cycles, }; static const struct stm32_adc_cfg stm32mp1_adc_cfg = { .regs = &stm32h7_adc_regspec, .adc_info = &stm32h7_adc_info, .trigs = stm32h7_adc_trigs, .has_vregready = true, .start_conv = stm32h7_adc_start_conv, .stop_conv = stm32h7_adc_stop_conv, .prepare = stm32h7_adc_prepare, .unprepare = stm32h7_adc_unprepare, .smp_cycles = stm32h7_adc_smp_cycles, }; static const struct of_device_id stm32_adc_of_match[] = { { .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg }, { .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg }, { .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg }, {}, }; MODULE_DEVICE_TABLE(of, stm32_adc_of_match); static struct platform_driver stm32_adc_driver = { .probe = stm32_adc_probe, .remove = stm32_adc_remove, .driver = { .name = "stm32-adc", .of_match_table = stm32_adc_of_match, .pm = &stm32_adc_pm_ops, }, }; module_platform_driver(stm32_adc_driver); MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:stm32-adc");
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