diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 9c4c1e23090a..48e560b7b851 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1222,6 +1222,18 @@ config NPCM_ADC This driver can also be built as a module. If so, the module will be called npcm_adc. +config NXP_SAR_ADC + tristate "NXP S32G SAR-ADC driver" + depends on ARCH_S32 || COMPILE_TEST + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for S32G platforms + analog-to-digital converter. + + This driver can also be built as a module. If so, the module will be + called nxp_sar_adc. + config PAC1921 tristate "Microchip Technology PAC1921 driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index ca3f87510331..05b01c00429f 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -108,6 +108,7 @@ obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o obj-$(CONFIG_NAU7802) += nau7802.o obj-$(CONFIG_NCT7201) += nct7201.o obj-$(CONFIG_NPCM_ADC) += npcm_adc.o +obj-$(CONFIG_NXP_SAR_ADC) += nxp-sar-adc.o obj-$(CONFIG_PAC1921) += pac1921.o obj-$(CONFIG_PAC1934) += pac1934.o obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o diff --git a/drivers/iio/adc/nxp-sar-adc.c b/drivers/iio/adc/nxp-sar-adc.c new file mode 100644 index 000000000000..9efa883c277d --- /dev/null +++ b/drivers/iio/adc/nxp-sar-adc.c @@ -0,0 +1,1016 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * NXP SAR-ADC driver (adapted from Freescale Vybrid vf610 ADC driver + * by Fugang Duan ) + * + * Copyright 2013 Freescale Semiconductor, Inc. + * Copyright 2017, 2020-2025 NXP + * Copyright 2025, Linaro Ltd + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* SAR ADC registers. */ +#define NXP_SAR_ADC_CDR(__base, __channel) (((__base) + 0x100) + ((__channel) * 0x4)) + +#define NXP_SAR_ADC_CDR_CDATA_MASK GENMASK(11, 0) +#define NXP_SAR_ADC_CDR_VALID BIT(19) + +/* Main Configuration Register */ +#define NXP_SAR_ADC_MCR(__base) ((__base) + 0x00) + +#define NXP_SAR_ADC_MCR_PWDN BIT(0) +#define NXP_SAR_ADC_MCR_ACKO BIT(5) +#define NXP_SAR_ADC_MCR_ADCLKSEL BIT(8) +#define NXP_SAR_ADC_MCR_TSAMP_MASK GENMASK(10, 9) +#define NXP_SAR_ADC_MCR_NRSMPL_MASK GENMASK(12, 11) +#define NXP_SAR_ADC_MCR_AVGEN BIT(13) +#define NXP_SAR_ADC_MCR_CALSTART BIT(14) +#define NXP_SAR_ADC_MCR_NSTART BIT(24) +#define NXP_SAR_ADC_MCR_MODE BIT(29) +#define NXP_SAR_ADC_MCR_OWREN BIT(31) + +/* Main Status Register */ +#define NXP_SAR_ADC_MSR(__base) ((__base) + 0x04) + +#define NXP_SAR_ADC_MSR_CALBUSY BIT(29) +#define NXP_SAR_ADC_MSR_CALFAIL BIT(30) + +/* Interrupt Status Register */ +#define NXP_SAR_ADC_ISR(__base) ((__base) + 0x10) + +#define NXP_SAR_ADC_ISR_ECH BIT(0) + +/* Channel Pending Register */ +#define NXP_SAR_ADC_CEOCFR0(__base) ((__base) + 0x14) +#define NXP_SAR_ADC_CEOCFR1(__base) ((__base) + 0x18) + +#define NXP_SAR_ADC_EOC_CH(c) BIT(c) + +/* Interrupt Mask Register */ +#define NXP_SAR_ADC_IMR(__base) ((__base) + 0x20) + +/* Channel Interrupt Mask Register */ +#define NXP_SAR_ADC_CIMR0(__base) ((__base) + 0x24) +#define NXP_SAR_ADC_CIMR1(__base) ((__base) + 0x28) + +/* DMA Setting Register */ +#define NXP_SAR_ADC_DMAE(__base) ((__base) + 0x40) + +#define NXP_SAR_ADC_DMAE_DMAEN BIT(0) +#define NXP_SAR_ADC_DMAE_DCLR BIT(1) + +/* DMA Control register */ +#define NXP_SAR_ADC_DMAR0(__base) ((__base) + 0x44) +#define NXP_SAR_ADC_DMAR1(__base) ((__base) + 0x48) + +/* Conversion Timing Register */ +#define NXP_SAR_ADC_CTR0(__base) ((__base) + 0x94) +#define NXP_SAR_ADC_CTR1(__base) ((__base) + 0x98) + +#define NXP_SAR_ADC_CTR_INPSAMP_MIN 0x08 +#define NXP_SAR_ADC_CTR_INPSAMP_MAX 0xff + +/* Normal Conversion Mask Register */ +#define NXP_SAR_ADC_NCMR0(__base) ((__base) + 0xa4) +#define NXP_SAR_ADC_NCMR1(__base) ((__base) + 0xa8) + +/* Normal Conversion Mask Register field define */ +#define NXP_SAR_ADC_CH_MASK GENMASK(7, 0) + +/* Other field define */ +#define NXP_SAR_ADC_CONV_TIMEOUT (msecs_to_jiffies(100)) +#define NXP_SAR_ADC_CAL_TIMEOUT_US (100 * USEC_PER_MSEC) +#define NXP_SAR_ADC_WAIT_US (2 * USEC_PER_MSEC) +#define NXP_SAR_ADC_RESOLUTION 12 + +/* Duration of conversion phases */ +#define NXP_SAR_ADC_TPT 2 +#define NXP_SAR_ADC_DP 2 +#define NXP_SAR_ADC_CT ((NXP_SAR_ADC_RESOLUTION + 2) * 4) +#define NXP_SAR_ADC_CONV_TIME (NXP_SAR_ADC_TPT + NXP_SAR_ADC_CT + NXP_SAR_ADC_DP) + +#define NXP_SAR_ADC_NR_CHANNELS 8 + +#define NXP_PAGE_SIZE SZ_4K +#define NXP_SAR_ADC_DMA_SAMPLE_SZ DMA_SLAVE_BUSWIDTH_4_BYTES +#define NXP_SAR_ADC_DMA_BUFF_SZ (NXP_PAGE_SIZE * NXP_SAR_ADC_DMA_SAMPLE_SZ) +#define NXP_SAR_ADC_DMA_SAMPLE_CNT (NXP_SAR_ADC_DMA_BUFF_SZ / NXP_SAR_ADC_DMA_SAMPLE_SZ) + +struct nxp_sar_adc { + void __iomem *regs; + phys_addr_t regs_phys; + u8 current_channel; + u8 channels_used; + u16 value; + u32 vref_mV; + + /* Save and restore context. */ + u32 inpsamp; + u32 pwdn; + + struct clk *clk; + struct dma_chan *dma_chan; + struct completion completion; + struct circ_buf dma_buf; + + dma_addr_t rx_dma_buf; + dma_cookie_t cookie; + + /* Protect circular buffers access. */ + spinlock_t lock; + + /* Array of enabled channels. */ + u16 buffered_chan[NXP_SAR_ADC_NR_CHANNELS]; + + /* Buffer to be filled by the DMA. */ + IIO_DECLARE_BUFFER_WITH_TS(u16, buffer, NXP_SAR_ADC_NR_CHANNELS); +}; + +struct nxp_sar_adc_data { + u32 vref_mV; + const char *model; +}; + +#define ADC_CHAN(_idx, _chan_type) { \ + .type = (_chan_type), \ + .indexed = 1, \ + .channel = (_idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .scan_index = (_idx), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + }, \ +} + +static const struct iio_chan_spec nxp_sar_adc_iio_channels[] = { + ADC_CHAN(0, IIO_VOLTAGE), + ADC_CHAN(1, IIO_VOLTAGE), + ADC_CHAN(2, IIO_VOLTAGE), + ADC_CHAN(3, IIO_VOLTAGE), + ADC_CHAN(4, IIO_VOLTAGE), + ADC_CHAN(5, IIO_VOLTAGE), + ADC_CHAN(6, IIO_VOLTAGE), + ADC_CHAN(7, IIO_VOLTAGE), + /* + * The NXP SAR ADC documentation marks the channels 8 to 31 as + * "Reserved". Reflect the same in the driver in case new ADC + * variants comes with more channels. + */ + IIO_CHAN_SOFT_TIMESTAMP(32), +}; + +static void nxp_sar_adc_irq_cfg(struct nxp_sar_adc *info, bool enable) +{ + if (enable) + writel(NXP_SAR_ADC_ISR_ECH, NXP_SAR_ADC_IMR(info->regs)); + else + writel(0, NXP_SAR_ADC_IMR(info->regs)); +} + +static bool nxp_sar_adc_set_enabled(struct nxp_sar_adc *info, bool enable) +{ + u32 mcr; + bool pwdn; + + mcr = readl(NXP_SAR_ADC_MCR(info->regs)); + + /* + * Get the current state and return it later. This is used for + * suspend/resume to get the power state + */ + pwdn = FIELD_GET(NXP_SAR_ADC_MCR_PWDN, mcr); + + /* When the enabled flag is not set, we set the power down bit */ + FIELD_MODIFY(NXP_SAR_ADC_MCR_PWDN, &mcr, !enable); + + writel(mcr, NXP_SAR_ADC_MCR(info->regs)); + + /* + * Ensure there are at least three cycles between the + * configuration of NCMR and the setting of NSTART. + */ + if (enable) + ndelay(div64_u64(NSEC_PER_SEC, clk_get_rate(info->clk) * 3)); + + return pwdn; +} + +static inline bool nxp_sar_adc_enable(struct nxp_sar_adc *info) +{ + return nxp_sar_adc_set_enabled(info, true); +} + +static inline bool nxp_sar_adc_disable(struct nxp_sar_adc *info) +{ + return nxp_sar_adc_set_enabled(info, false); +} + +static inline void nxp_sar_adc_calibration_start(void __iomem *base) +{ + u32 mcr = readl(NXP_SAR_ADC_MCR(base)); + + FIELD_MODIFY(NXP_SAR_ADC_MCR_CALSTART, &mcr, 0x1); + + writel(mcr, NXP_SAR_ADC_MCR(base)); +} + +static inline int nxp_sar_adc_calibration_wait(void __iomem *base) +{ + u32 msr, ret; + + ret = readl_poll_timeout(NXP_SAR_ADC_MSR(base), msr, + !FIELD_GET(NXP_SAR_ADC_MSR_CALBUSY, msr), + NXP_SAR_ADC_WAIT_US, + NXP_SAR_ADC_CAL_TIMEOUT_US); + if (ret) + return ret; + + if (FIELD_GET(NXP_SAR_ADC_MSR_CALFAIL, msr)) { + /* + * If the calibration fails, the status register bit must be + * cleared. + */ + FIELD_MODIFY(NXP_SAR_ADC_MSR_CALFAIL, &msr, 0x0); + writel(msr, NXP_SAR_ADC_MSR(base)); + + return -EAGAIN; + } + + return 0; +} + +static int nxp_sar_adc_calibration(struct nxp_sar_adc *info) +{ + int ret; + + /* Calibration works only if the ADC is powered up. */ + nxp_sar_adc_enable(info); + + /* The calibration operation starts. */ + nxp_sar_adc_calibration_start(info->regs); + + ret = nxp_sar_adc_calibration_wait(info->regs); + + /* + * Calibration works only if the ADC is powered up. However + * the calibration is called from the probe function where the + * iio is not enabled, so we disable after the calibration. + */ + nxp_sar_adc_disable(info); + + return ret; +} + +static void nxp_sar_adc_conversion_timing_set(struct nxp_sar_adc *info, u32 inpsamp) +{ + inpsamp = clamp(inpsamp, NXP_SAR_ADC_CTR_INPSAMP_MIN, NXP_SAR_ADC_CTR_INPSAMP_MAX); + + writel(inpsamp, NXP_SAR_ADC_CTR0(info->regs)); +} + +static u32 nxp_sar_adc_conversion_timing_get(struct nxp_sar_adc *info) +{ + return readl(NXP_SAR_ADC_CTR0(info->regs)); +} + +static void nxp_sar_adc_read_notify(struct nxp_sar_adc *info) +{ + writel(NXP_SAR_ADC_CH_MASK, NXP_SAR_ADC_CEOCFR0(info->regs)); + writel(NXP_SAR_ADC_CH_MASK, NXP_SAR_ADC_CEOCFR1(info->regs)); +} + +static int nxp_sar_adc_read_data(struct nxp_sar_adc *info, unsigned int chan) +{ + u32 ceocfr, cdr; + + ceocfr = readl(NXP_SAR_ADC_CEOCFR0(info->regs)); + + /* + * FIELD_GET() can not be used here because EOC_CH is not constant. + * TODO: Switch to field_get() when it will be available. + */ + if (!(NXP_SAR_ADC_EOC_CH(chan) & ceocfr)) + return -EIO; + + cdr = readl(NXP_SAR_ADC_CDR(info->regs, chan)); + if (!(FIELD_GET(NXP_SAR_ADC_CDR_VALID, cdr))) + return -EIO; + + return FIELD_GET(NXP_SAR_ADC_CDR_CDATA_MASK, cdr); +} + +static void nxp_sar_adc_isr_buffer(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + unsigned int i; + int ret; + + for (i = 0; i < info->channels_used; i++) { + ret = nxp_sar_adc_read_data(info, info->buffered_chan[i]); + if (ret < 0) { + nxp_sar_adc_read_notify(info); + return; + } + + info->buffer[i] = ret; + } + + nxp_sar_adc_read_notify(info); + + iio_push_to_buffers_with_ts(indio_dev, info->buffer, sizeof(info->buffer), + iio_get_time_ns(indio_dev)); + + iio_trigger_notify_done(indio_dev->trig); +} + +static void nxp_sar_adc_isr_read_raw(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + int ret; + + ret = nxp_sar_adc_read_data(info, info->current_channel); + nxp_sar_adc_read_notify(info); + if (ret < 0) + return; + + info->value = ret; + complete(&info->completion); +} + +static irqreturn_t nxp_sar_adc_isr(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct nxp_sar_adc *info = iio_priv(indio_dev); + int isr; + + isr = readl(NXP_SAR_ADC_ISR(info->regs)); + if (!(FIELD_GET(NXP_SAR_ADC_ISR_ECH, isr))) + return IRQ_NONE; + + if (iio_buffer_enabled(indio_dev)) + nxp_sar_adc_isr_buffer(indio_dev); + else + nxp_sar_adc_isr_read_raw(indio_dev); + + writel(NXP_SAR_ADC_ISR_ECH, NXP_SAR_ADC_ISR(info->regs)); + + return IRQ_HANDLED; +} + +static void nxp_sar_adc_channels_disable(struct nxp_sar_adc *info, u32 mask) +{ + u32 ncmr, cimr; + + ncmr = readl(NXP_SAR_ADC_NCMR0(info->regs)); + cimr = readl(NXP_SAR_ADC_CIMR0(info->regs)); + + /* FIELD_MODIFY() can not be used because the mask is not constant */ + ncmr &= ~mask; + cimr &= ~mask; + + writel(ncmr, NXP_SAR_ADC_NCMR0(info->regs)); + writel(cimr, NXP_SAR_ADC_CIMR0(info->regs)); +} + +static void nxp_sar_adc_channels_enable(struct nxp_sar_adc *info, u32 mask) +{ + u32 ncmr, cimr; + + ncmr = readl(NXP_SAR_ADC_NCMR0(info->regs)); + cimr = readl(NXP_SAR_ADC_CIMR0(info->regs)); + + ncmr |= mask; + cimr |= mask; + + writel(ncmr, NXP_SAR_ADC_NCMR0(info->regs)); + writel(cimr, NXP_SAR_ADC_CIMR0(info->regs)); +} + +static void nxp_sar_adc_dma_channels_enable(struct nxp_sar_adc *info, u32 mask) +{ + u32 dmar; + + dmar = readl(NXP_SAR_ADC_DMAR0(info->regs)); + + dmar |= mask; + + writel(dmar, NXP_SAR_ADC_DMAR0(info->regs)); +} + +static void nxp_sar_adc_dma_channels_disable(struct nxp_sar_adc *info, u32 mask) +{ + u32 dmar; + + dmar = readl(NXP_SAR_ADC_DMAR0(info->regs)); + + dmar &= ~mask; + + writel(dmar, NXP_SAR_ADC_DMAR0(info->regs)); +} + +static void nxp_sar_adc_dma_cfg(struct nxp_sar_adc *info, bool enable) +{ + u32 dmae; + + dmae = readl(NXP_SAR_ADC_DMAE(info->regs)); + + FIELD_MODIFY(NXP_SAR_ADC_DMAE_DMAEN, &dmae, enable); + + writel(dmae, NXP_SAR_ADC_DMAE(info->regs)); +} + +static void nxp_sar_adc_stop_conversion(struct nxp_sar_adc *info) +{ + u32 mcr; + + mcr = readl(NXP_SAR_ADC_MCR(info->regs)); + + FIELD_MODIFY(NXP_SAR_ADC_MCR_NSTART, &mcr, 0x0); + + writel(mcr, NXP_SAR_ADC_MCR(info->regs)); + + /* + * On disable, we have to wait for the transaction to finish. + * ADC does not abort the transaction if a chain conversion is + * in progress. Wait for the worst case scenario - 80 ADC clk + * cycles. The clock rate is 80MHz, this routine is called + * only when the capture finishes. The delay will be very + * short, usec-ish, which is acceptable in the atomic context. + */ + ndelay(div64_u64(NSEC_PER_SEC, clk_get_rate(info->clk)) * 80); +} + +static int nxp_sar_adc_start_conversion(struct nxp_sar_adc *info, bool raw) +{ + u32 mcr; + + mcr = readl(NXP_SAR_ADC_MCR(info->regs)); + + FIELD_MODIFY(NXP_SAR_ADC_MCR_NSTART, &mcr, 0x1); + FIELD_MODIFY(NXP_SAR_ADC_MCR_MODE, &mcr, raw ? 0 : 1); + + writel(mcr, NXP_SAR_ADC_MCR(info->regs)); + + return 0; +} + +static int nxp_sar_adc_read_channel(struct nxp_sar_adc *info, int channel) +{ + int ret; + + info->current_channel = channel; + nxp_sar_adc_channels_enable(info, BIT(channel)); + nxp_sar_adc_irq_cfg(info, true); + nxp_sar_adc_enable(info); + + reinit_completion(&info->completion); + ret = nxp_sar_adc_start_conversion(info, true); + if (ret < 0) + goto out_disable; + + if (!wait_for_completion_interruptible_timeout(&info->completion, + NXP_SAR_ADC_CONV_TIMEOUT)) + ret = -ETIMEDOUT; + + nxp_sar_adc_stop_conversion(info); + +out_disable: + nxp_sar_adc_channels_disable(info, BIT(channel)); + nxp_sar_adc_irq_cfg(info, false); + nxp_sar_adc_disable(info); + + return ret; +} + +static int nxp_sar_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + u32 inpsamp; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = nxp_sar_adc_read_channel(info, chan->channel); + + iio_device_release_direct(indio_dev); + + if (ret) + return ret; + + *val = info->value; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = info->vref_mV; + *val2 = NXP_SAR_ADC_RESOLUTION; + return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_SAMP_FREQ: + inpsamp = nxp_sar_adc_conversion_timing_get(info); + *val = clk_get_rate(info->clk) / (inpsamp + NXP_SAR_ADC_CONV_TIME); + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static int nxp_sar_adc_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + u32 inpsamp; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + /* + * Configures the sample period duration in terms of the SAR + * controller clock. The minimum acceptable value is 8. + * Configuring it to a value lower than 8 sets the sample period + * to 8 cycles. We read the clock value and divide by the + * sampling timing which gives us the number of cycles expected. + * The value is 8-bit wide, consequently the max value is 0xFF. + */ + inpsamp = clk_get_rate(info->clk) / val - NXP_SAR_ADC_CONV_TIME; + nxp_sar_adc_conversion_timing_set(info, inpsamp); + return 0; + + default: + return -EINVAL; + } +} + +static void nxp_sar_adc_dma_cb(void *data) +{ + struct iio_dev *indio_dev = data; + struct nxp_sar_adc *info = iio_priv(indio_dev); + struct dma_tx_state state; + struct circ_buf *dma_buf; + struct device *dev_dma; + u32 *dma_samples; + s64 timestamp; + int idx, ret; + + guard(spinlock_irqsave)(&info->lock); + + dma_buf = &info->dma_buf; + dma_samples = (u32 *)dma_buf->buf; + dev_dma = info->dma_chan->device->dev; + + /* + * DMA in some corner cases might have already be charged for + * the next transfer. Potentially there can be a race where + * the residue changes while the dma engine updates the + * buffer. That could be handled by using the + * callback_result() instead of callback() because the residue + * will be passed as a parameter to the function. However this + * new callback is pretty new and the backend does not update + * the residue. So let's stick to the version other drivers do + * which has proven running well in production since several + * years. + */ + dmaengine_tx_status(info->dma_chan, info->cookie, &state); + + dma_sync_single_for_cpu(dev_dma, info->rx_dma_buf, + NXP_SAR_ADC_DMA_BUFF_SZ, DMA_FROM_DEVICE); + + /* Current head position. */ + dma_buf->head = (NXP_SAR_ADC_DMA_BUFF_SZ - state.residue) / + NXP_SAR_ADC_DMA_SAMPLE_SZ; + + /* If everything was transferred, avoid an off by one error. */ + if (!state.residue) + dma_buf->head--; + + /* Something went wrong and nothing transferred. */ + if (state.residue != NXP_SAR_ADC_DMA_BUFF_SZ) { + /* Make sure that head is multiple of info->channels_used. */ + dma_buf->head -= dma_buf->head % info->channels_used; + + /* + * dma_buf->tail != dma_buf->head condition will become false + * because dma_buf->tail will be incremented with 1. + */ + while (dma_buf->tail != dma_buf->head) { + idx = dma_buf->tail % info->channels_used; + info->buffer[idx] = dma_samples[dma_buf->tail]; + dma_buf->tail = (dma_buf->tail + 1) % NXP_SAR_ADC_DMA_SAMPLE_CNT; + if (idx != info->channels_used - 1) + continue; + + /* + * iio_push_to_buffers_with_ts() should not be + * called with dma_samples as parameter. The samples + * will be smashed if timestamp is enabled. + */ + timestamp = iio_get_time_ns(indio_dev); + ret = iio_push_to_buffers_with_ts(indio_dev, info->buffer, + sizeof(info->buffer), + timestamp); + if (ret < 0 && ret != -EBUSY) + dev_err_ratelimited(&indio_dev->dev, + "failed to push iio buffer: %d", + ret); + } + + dma_buf->tail = dma_buf->head; + } + + dma_sync_single_for_device(dev_dma, info->rx_dma_buf, + NXP_SAR_ADC_DMA_BUFF_SZ, DMA_FROM_DEVICE); +} + +static int nxp_sar_adc_start_cyclic_dma(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + struct dma_slave_config config; + struct dma_async_tx_descriptor *desc; + int ret; + + info->dma_buf.head = 0; + info->dma_buf.tail = 0; + + config.direction = DMA_DEV_TO_MEM; + config.src_addr_width = NXP_SAR_ADC_DMA_SAMPLE_SZ; + config.src_addr = NXP_SAR_ADC_CDR(info->regs_phys, info->buffered_chan[0]); + config.src_port_window_size = info->channels_used; + config.src_maxburst = info->channels_used; + ret = dmaengine_slave_config(info->dma_chan, &config); + if (ret < 0) + return ret; + + desc = dmaengine_prep_dma_cyclic(info->dma_chan, + info->rx_dma_buf, + NXP_SAR_ADC_DMA_BUFF_SZ, + NXP_SAR_ADC_DMA_BUFF_SZ / 2, + DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); + if (!desc) + return -EINVAL; + + desc->callback = nxp_sar_adc_dma_cb; + desc->callback_param = indio_dev; + info->cookie = dmaengine_submit(desc); + ret = dma_submit_error(info->cookie); + if (ret) { + dmaengine_terminate_async(info->dma_chan); + return ret; + } + + dma_async_issue_pending(info->dma_chan); + + return 0; +} + +static void nxp_sar_adc_buffer_software_do_predisable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + + /* + * The ADC DMAEN bit should be cleared before DMA transaction + * is canceled. + */ + nxp_sar_adc_stop_conversion(info); + dmaengine_terminate_sync(info->dma_chan); + nxp_sar_adc_dma_cfg(info, false); + nxp_sar_adc_dma_channels_disable(info, *indio_dev->active_scan_mask); + + dma_release_channel(info->dma_chan); +} + +static int nxp_sar_adc_buffer_software_do_postenable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + int ret; + + nxp_sar_adc_dma_channels_enable(info, *indio_dev->active_scan_mask); + + nxp_sar_adc_dma_cfg(info, true); + + ret = nxp_sar_adc_start_cyclic_dma(indio_dev); + if (ret) + goto out_dma_channels_disable; + + ret = nxp_sar_adc_start_conversion(info, false); + if (ret) + goto out_stop_cyclic_dma; + + return 0; + +out_stop_cyclic_dma: + dmaengine_terminate_sync(info->dma_chan); + +out_dma_channels_disable: + nxp_sar_adc_dma_cfg(info, false); + nxp_sar_adc_dma_channels_disable(info, *indio_dev->active_scan_mask); + + return ret; +} + +static void nxp_sar_adc_buffer_trigger_do_predisable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + + nxp_sar_adc_irq_cfg(info, false); +} + +static int nxp_sar_adc_buffer_trigger_do_postenable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + + nxp_sar_adc_irq_cfg(info, true); + + return 0; +} + +static int nxp_sar_adc_buffer_postenable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + int current_mode = iio_device_get_current_mode(indio_dev); + unsigned long channel; + int ret; + + info->dma_chan = dma_request_chan(indio_dev->dev.parent, "rx"); + if (IS_ERR(info->dma_chan)) + return PTR_ERR(info->dma_chan); + + info->channels_used = 0; + + /* + * The SAR-ADC has two groups of channels. + * + * - Group #0: + * * bit 0-7 : channel 0 -> channel 7 + * * bit 8-31 : reserved + * + * - Group #32: + * * bit 0-7 : Internal + * * bit 8-31 : reserved + * + * The 8 channels from group #0 are used in this driver for + * ADC as described when declaring the IIO device and the + * mapping is the same. That means the active_scan_mask can be + * used directly to write the channel interrupt mask. + */ + nxp_sar_adc_channels_enable(info, *indio_dev->active_scan_mask); + + for_each_set_bit(channel, indio_dev->active_scan_mask, NXP_SAR_ADC_NR_CHANNELS) + info->buffered_chan[info->channels_used++] = channel; + + nxp_sar_adc_enable(info); + + if (current_mode == INDIO_BUFFER_SOFTWARE) + ret = nxp_sar_adc_buffer_software_do_postenable(indio_dev); + else + ret = nxp_sar_adc_buffer_trigger_do_postenable(indio_dev); + if (ret) + goto out_postenable; + + return 0; + +out_postenable: + nxp_sar_adc_disable(info); + nxp_sar_adc_channels_disable(info, *indio_dev->active_scan_mask); + + return ret; +} + +static int nxp_sar_adc_buffer_predisable(struct iio_dev *indio_dev) +{ + struct nxp_sar_adc *info = iio_priv(indio_dev); + int currentmode = iio_device_get_current_mode(indio_dev); + + if (currentmode == INDIO_BUFFER_SOFTWARE) + nxp_sar_adc_buffer_software_do_predisable(indio_dev); + else + nxp_sar_adc_buffer_trigger_do_predisable(indio_dev); + + nxp_sar_adc_disable(info); + + nxp_sar_adc_channels_disable(info, *indio_dev->active_scan_mask); + + return 0; +} + +static irqreturn_t nxp_sar_adc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct nxp_sar_adc *info = iio_priv(indio_dev); + int ret; + + ret = nxp_sar_adc_start_conversion(info, true); + if (ret < 0) + dev_dbg(&indio_dev->dev, "Failed to start conversion\n"); + + return IRQ_HANDLED; +} + +static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { + .postenable = nxp_sar_adc_buffer_postenable, + .predisable = nxp_sar_adc_buffer_predisable, +}; + +static const struct iio_info nxp_sar_adc_iio_info = { + .read_raw = nxp_sar_adc_read_raw, + .write_raw = nxp_sar_adc_write_raw, +}; + +static int nxp_sar_adc_dma_probe(struct device *dev, struct nxp_sar_adc *info) +{ + u8 *rx_buf; + + rx_buf = dmam_alloc_coherent(dev, NXP_SAR_ADC_DMA_BUFF_SZ, + &info->rx_dma_buf, GFP_KERNEL); + if (!rx_buf) + return -ENOMEM; + + info->dma_buf.buf = rx_buf; + + return 0; +} + +/* + * The documentation describes the reset values for the registers. + * However some registers do not have these values after a reset. It + * is not a desirable situation. In some other SoC family + * documentation NXP recommends not assuming the default values are + * set and to initialize the registers conforming to the documentation + * reset information to prevent this situation. Assume the same rule + * applies here as there is a discrepancy between what is read from + * the registers at reset time and the documentation. + */ +static void nxp_sar_adc_set_default_values(struct nxp_sar_adc *info) +{ + writel(0x00003901, NXP_SAR_ADC_MCR(info->regs)); + writel(0x00000001, NXP_SAR_ADC_MSR(info->regs)); + writel(0x00000014, NXP_SAR_ADC_CTR0(info->regs)); + writel(0x00000014, NXP_SAR_ADC_CTR1(info->regs)); + writel(0x00000000, NXP_SAR_ADC_CIMR0(info->regs)); + writel(0x00000000, NXP_SAR_ADC_CIMR1(info->regs)); + writel(0x00000000, NXP_SAR_ADC_NCMR0(info->regs)); + writel(0x00000000, NXP_SAR_ADC_NCMR1(info->regs)); +} + +static int nxp_sar_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct nxp_sar_adc_data *data = device_get_match_data(dev); + struct nxp_sar_adc *info; + struct iio_dev *indio_dev; + struct resource *mem; + int irq, ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*info)); + if (!indio_dev) + return -ENOMEM; + + info = iio_priv(indio_dev); + info->vref_mV = data->vref_mV; + spin_lock_init(&info->lock); + info->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); + if (IS_ERR(info->regs)) + return dev_err_probe(dev, PTR_ERR(info->regs), + "Failed to get and remap resource"); + + info->regs_phys = mem->start; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, nxp_sar_adc_isr, 0, dev_name(dev), + indio_dev); + if (ret < 0) + return ret; + + info->clk = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(info->clk)) + return dev_err_probe(dev, PTR_ERR(info->clk), + "Failed to get the clock\n"); + + platform_set_drvdata(pdev, indio_dev); + + init_completion(&info->completion); + + indio_dev->name = data->model; + indio_dev->info = &nxp_sar_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + indio_dev->channels = nxp_sar_adc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(nxp_sar_adc_iio_channels); + + nxp_sar_adc_set_default_values(info); + + ret = nxp_sar_adc_calibration(info); + if (ret) + dev_err_probe(dev, ret, "Calibration failed\n"); + + ret = nxp_sar_adc_dma_probe(dev, info); + if (ret) + return dev_err_probe(dev, ret, "Failed to initialize the DMA\n"); + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + &iio_pollfunc_store_time, + &nxp_sar_adc_trigger_handler, + &iio_triggered_buffer_setup_ops); + if (ret < 0) + return dev_err_probe(dev, ret, "Couldn't initialise the buffer\n"); + + ret = devm_iio_device_register(dev, indio_dev); + if (ret) + return dev_err_probe(dev, ret, "Couldn't register the device\n"); + + return 0; +} + +static int nxp_sar_adc_suspend(struct device *dev) +{ + struct nxp_sar_adc *info = iio_priv(dev_get_drvdata(dev)); + + info->pwdn = nxp_sar_adc_disable(info); + info->inpsamp = nxp_sar_adc_conversion_timing_get(info); + + clk_disable_unprepare(info->clk); + + return 0; +} + +static int nxp_sar_adc_resume(struct device *dev) +{ + struct nxp_sar_adc *info = iio_priv(dev_get_drvdata(dev)); + int ret; + + ret = clk_prepare_enable(info->clk); + if (ret) + return ret; + + nxp_sar_adc_conversion_timing_set(info, info->inpsamp); + + if (!info->pwdn) + nxp_sar_adc_enable(info); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(nxp_sar_adc_pm_ops, nxp_sar_adc_suspend, + nxp_sar_adc_resume); + +static const struct nxp_sar_adc_data s32g2_sar_adc_data = { + .vref_mV = 1800, + .model = "s32g2-sar-adc", +}; + +static const struct of_device_id nxp_sar_adc_match[] = { + { .compatible = "nxp,s32g2-sar-adc", .data = &s32g2_sar_adc_data }, + { } +}; +MODULE_DEVICE_TABLE(of, nxp_sar_adc_match); + +static struct platform_driver nxp_sar_adc_driver = { + .probe = nxp_sar_adc_probe, + .driver = { + .name = "nxp-sar-adc", + .of_match_table = nxp_sar_adc_match, + .pm = pm_sleep_ptr(&nxp_sar_adc_pm_ops), + }, +}; +module_platform_driver(nxp_sar_adc_driver); + +MODULE_AUTHOR("NXP"); +MODULE_DESCRIPTION("NXP SAR-ADC driver"); +MODULE_LICENSE("GPL");