diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/iio/adc/stm32-dfsdm-adc.c | 1229 |
1 files changed, 1229 insertions, 0 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c new file mode 100644 index 000000000..1c492a7f4 --- /dev/null +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -0,0 +1,1229 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This file is the ADC part of the STM32 DFSDM driver + * + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved + * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>. + */ + +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/iio/adc/stm32-dfsdm-adc.h> +#include <linux/iio/buffer.h> +#include <linux/iio/hw-consumer.h> +#include <linux/iio/sysfs.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include "stm32-dfsdm.h" + +#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE) + +/* Conversion timeout */ +#define DFSDM_TIMEOUT_US 100000 +#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000)) + +/* Oversampling attribute default */ +#define DFSDM_DEFAULT_OVERSAMPLING 100 + +/* Oversampling max values */ +#define DFSDM_MAX_INT_OVERSAMPLING 256 +#define DFSDM_MAX_FL_OVERSAMPLING 1024 + +/* Max sample resolutions */ +#define DFSDM_MAX_RES BIT(31) +#define DFSDM_DATA_RES BIT(23) + +enum sd_converter_type { + DFSDM_AUDIO, + DFSDM_IIO, +}; + +struct stm32_dfsdm_dev_data { + int type; + int (*init)(struct device *dev, struct iio_dev *indio_dev); + unsigned int num_channels; + const struct regmap_config *regmap_cfg; +}; + +struct stm32_dfsdm_adc { + struct stm32_dfsdm *dfsdm; + const struct stm32_dfsdm_dev_data *dev_data; + unsigned int fl_id; + + /* ADC specific */ + unsigned int oversamp; + struct iio_hw_consumer *hwc; + struct completion completion; + u32 *buffer; + + /* Audio specific */ + unsigned int spi_freq; /* SPI bus clock frequency */ + unsigned int sample_freq; /* Sample frequency after filter decimation */ + int (*cb)(const void *data, size_t size, void *cb_priv); + void *cb_priv; + + /* DMA */ + u8 *rx_buf; + unsigned int bufi; /* Buffer current position */ + unsigned int buf_sz; /* Buffer size */ + struct dma_chan *dma_chan; + dma_addr_t dma_buf; +}; + +struct stm32_dfsdm_str2field { + const char *name; + unsigned int val; +}; + +/* DFSDM channel serial interface type */ +static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = { + { "SPI_R", 0 }, /* SPI with data on rising edge */ + { "SPI_F", 1 }, /* SPI with data on falling edge */ + { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */ + { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */ + {}, +}; + +/* DFSDM channel clock source */ +static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = { + /* External SPI clock (CLKIN x) */ + { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL }, + /* Internal SPI clock (CLKOUT) */ + { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL }, + /* Internal SPI clock divided by 2 (falling edge) */ + { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING }, + /* Internal SPI clock divided by 2 (falling edge) */ + { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING }, + {}, +}; + +static int stm32_dfsdm_str2val(const char *str, + const struct stm32_dfsdm_str2field *list) +{ + const struct stm32_dfsdm_str2field *p = list; + + for (p = list; p && p->name; p++) + if (!strcmp(p->name, str)) + return p->val; + + return -EINVAL; +} + +static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, + unsigned int fast, unsigned int oversamp) +{ + unsigned int i, d, fosr, iosr; + u64 res; + s64 delta; + unsigned int m = 1; /* multiplication factor */ + unsigned int p = fl->ford; /* filter order (ford) */ + + pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp); + /* + * This function tries to compute filter oversampling and integrator + * oversampling, base on oversampling ratio requested by user. + * + * Decimation d depends on the filter order and the oversampling ratios. + * ford: filter order + * fosr: filter over sampling ratio + * iosr: integrator over sampling ratio + */ + if (fl->ford == DFSDM_FASTSINC_ORDER) { + m = 2; + p = 2; + } + + /* + * Look for filter and integrator oversampling ratios which allows + * to reach 24 bits data output resolution. + * Leave as soon as if exact resolution if reached. + * Otherwise the higher resolution below 32 bits is kept. + */ + fl->res = 0; + for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { + for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { + if (fast) + d = fosr * iosr; + else if (fl->ford == DFSDM_FASTSINC_ORDER) + d = fosr * (iosr + 3) + 2; + else + d = fosr * (iosr - 1 + p) + p; + + if (d > oversamp) + break; + else if (d != oversamp) + continue; + /* + * Check resolution (limited to signed 32 bits) + * res <= 2^31 + * Sincx filters: + * res = m * fosr^p x iosr (with m=1, p=ford) + * FastSinc filter + * res = m * fosr^p x iosr (with m=2, p=2) + */ + res = fosr; + for (i = p - 1; i > 0; i--) { + res = res * (u64)fosr; + if (res > DFSDM_MAX_RES) + break; + } + if (res > DFSDM_MAX_RES) + continue; + res = res * (u64)m * (u64)iosr; + if (res > DFSDM_MAX_RES) + continue; + + delta = res - DFSDM_DATA_RES; + + if (res >= fl->res) { + fl->res = res; + fl->fosr = fosr; + fl->iosr = iosr; + fl->fast = fast; + pr_debug("%s: fosr = %d, iosr = %d\n", + __func__, fl->fosr, fl->iosr); + } + + if (!delta) + return 0; + } + } + + if (!fl->res) + return -EINVAL; + + return 0; +} + +static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm, + unsigned int ch_id) +{ + return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id), + DFSDM_CHCFGR1_CHEN_MASK, + DFSDM_CHCFGR1_CHEN(1)); +} + +static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm, + unsigned int ch_id) +{ + regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id), + DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0)); +} + +static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm, + struct stm32_dfsdm_channel *ch) +{ + unsigned int id = ch->id; + struct regmap *regmap = dfsdm->regmap; + int ret; + + ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_SITP_MASK, + DFSDM_CHCFGR1_SITP(ch->type)); + if (ret < 0) + return ret; + ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_SPICKSEL_MASK, + DFSDM_CHCFGR1_SPICKSEL(ch->src)); + if (ret < 0) + return ret; + return regmap_update_bits(regmap, DFSDM_CHCFGR1(id), + DFSDM_CHCFGR1_CHINSEL_MASK, + DFSDM_CHCFGR1_CHINSEL(ch->alt_si)); +} + +static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm, + unsigned int fl_id) +{ + int ret; + + /* Enable filter */ + ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1)); + if (ret < 0) + return ret; + + /* Start conversion */ + return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_RSWSTART_MASK, + DFSDM_CR1_RSWSTART(1)); +} + +static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, + unsigned int fl_id) +{ + /* Disable conversion */ + regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0)); +} + +static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm, + unsigned int fl_id, unsigned int ch_id) +{ + struct regmap *regmap = dfsdm->regmap; + struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id]; + int ret; + + /* Average integrator oversampling */ + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK, + DFSDM_FCR_IOSR(fl->iosr - 1)); + if (ret) + return ret; + + /* Filter order and Oversampling */ + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK, + DFSDM_FCR_FOSR(fl->fosr - 1)); + if (ret) + return ret; + + ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK, + DFSDM_FCR_FORD(fl->ford)); + if (ret) + return ret; + + /* No scan mode supported for the moment */ + ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK, + DFSDM_CR1_RCH(ch_id)); + if (ret) + return ret; + + return regmap_update_bits(regmap, DFSDM_CR1(fl_id), + DFSDM_CR1_RSYNC_MASK, + DFSDM_CR1_RSYNC(fl->sync_mode)); +} + +static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, + struct iio_dev *indio_dev, + struct iio_chan_spec *ch) +{ + struct stm32_dfsdm_channel *df_ch; + const char *of_str; + int chan_idx = ch->scan_index; + int ret, val; + + ret = of_property_read_u32_index(indio_dev->dev.of_node, + "st,adc-channels", chan_idx, + &ch->channel); + if (ret < 0) { + dev_err(&indio_dev->dev, + " Error parsing 'st,adc-channels' for idx %d\n", + chan_idx); + return ret; + } + if (ch->channel >= dfsdm->num_chs) { + dev_err(&indio_dev->dev, + " Error bad channel number %d (max = %d)\n", + ch->channel, dfsdm->num_chs); + return -EINVAL; + } + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-names", chan_idx, + &ch->datasheet_name); + if (ret < 0) { + dev_err(&indio_dev->dev, + " Error parsing 'st,adc-channel-names' for idx %d\n", + chan_idx); + return ret; + } + + df_ch = &dfsdm->ch_list[ch->channel]; + df_ch->id = ch->channel; + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-types", chan_idx, + &of_str); + if (!ret) { + val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type); + if (val < 0) + return val; + } else { + val = 0; + } + df_ch->type = val; + + ret = of_property_read_string_index(indio_dev->dev.of_node, + "st,adc-channel-clk-src", chan_idx, + &of_str); + if (!ret) { + val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src); + if (val < 0) + return val; + } else { + val = 0; + } + df_ch->src = val; + + ret = of_property_read_u32_index(indio_dev->dev.of_node, + "st,adc-alt-channel", chan_idx, + &df_ch->alt_si); + if (ret < 0) + df_ch->alt_si = 0; + + return 0; +} + +static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev, + uintptr_t priv, + const struct iio_chan_spec *chan, + char *buf) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq); +} + +static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev, + uintptr_t priv, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel]; + unsigned int sample_freq = adc->sample_freq; + unsigned int spi_freq; + int ret; + + dev_err(&indio_dev->dev, "enter %s\n", __func__); + /* If DFSDM is master on SPI, SPI freq can not be updated */ + if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + return -EPERM; + + ret = kstrtoint(buf, 0, &spi_freq); + if (ret) + return ret; + + if (!spi_freq) + return -EINVAL; + + if (sample_freq) { + if (spi_freq % sample_freq) + dev_warn(&indio_dev->dev, + "Sampling rate not accurate (%d)\n", + spi_freq / (spi_freq / sample_freq)); + + ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq)); + if (ret < 0) { + dev_err(&indio_dev->dev, + "No filter parameters that match!\n"); + return ret; + } + } + adc->spi_freq = spi_freq; + + return len; +} + +static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, + const struct iio_chan_spec *chan, + bool dma) +{ + struct regmap *regmap = adc->dfsdm->regmap; + int ret; + unsigned int dma_en = 0, cont_en = 0; + + ret = stm32_dfsdm_start_channel(adc->dfsdm, chan->channel); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id, + chan->channel); + if (ret < 0) + goto stop_channels; + + if (dma) { + /* Enable DMA transfer*/ + dma_en = DFSDM_CR1_RDMAEN(1); + /* Enable conversion triggered by SPI clock*/ + cont_en = DFSDM_CR1_RCONT(1); + } + /* Enable DMA transfer*/ + ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RDMAEN_MASK, dma_en); + if (ret < 0) + goto stop_channels; + + /* Enable conversion triggered by SPI clock*/ + ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RCONT_MASK, cont_en); + if (ret < 0) + goto stop_channels; + + ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id); + if (ret < 0) + goto stop_channels; + + return 0; + +stop_channels: + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RDMAEN_MASK, 0); + + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RCONT_MASK, 0); + stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel); + + return ret; +} + +static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc, + const struct iio_chan_spec *chan) +{ + struct regmap *regmap = adc->dfsdm->regmap; + + stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id); + + /* Clean conversion options */ + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RDMAEN_MASK, 0); + + regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id), + DFSDM_CR1_RCONT_MASK, 0); + + stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel); +} + +static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev, + unsigned int val) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2; + + /* + * 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 pushed to ASoC side. + */ + watermark = min(watermark, val * (unsigned int)(sizeof(u32))); + adc->buf_sz = watermark * 2; + + return 0; +} + +static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_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->buf_sz - state.residue; + unsigned int size; + + /* Return available bytes */ + if (i >= adc->bufi) + size = i - adc->bufi; + else + size = adc->buf_sz + i - adc->bufi; + + return size; + } + + return 0; +} + +static void stm32_dfsdm_audio_dma_buffer_done(void *data) +{ + struct iio_dev *indio_dev = data; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int available = stm32_dfsdm_adc_dma_residue(adc); + size_t old_pos; + + /* + * FIXME: In Kernel interface does not support cyclic DMA buffer,and + * offers only an interface to push data samples per samples. + * For this reason IIO buffer interface is not used and interface is + * bypassed using a private callback registered by ASoC. + * This should be a temporary solution waiting a cyclic DMA engine + * support in IIO. + */ + + dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__, + adc->bufi, available); + old_pos = adc->bufi; + + while (available >= indio_dev->scan_bytes) { + u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi]; + + /* Mask 8 LSB that contains the channel ID */ + *buffer = (*buffer & 0xFFFFFF00) << 8; + available -= indio_dev->scan_bytes; + adc->bufi += indio_dev->scan_bytes; + if (adc->bufi >= adc->buf_sz) { + if (adc->cb) + adc->cb(&adc->rx_buf[old_pos], + adc->buf_sz - old_pos, adc->cb_priv); + adc->bufi = 0; + old_pos = 0; + } + } + if (adc->cb) + adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos, + adc->cb_priv); +} + +static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct dma_async_tx_descriptor *desc; + dma_cookie_t cookie; + int ret; + + if (!adc->dma_chan) + return -EINVAL; + + dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__, + adc->buf_sz, adc->buf_sz / 2); + + /* Prepare a DMA cyclic transaction */ + desc = dmaengine_prep_dma_cyclic(adc->dma_chan, + adc->dma_buf, + adc->buf_sz, adc->buf_sz / 2, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!desc) + return -EBUSY; + + desc->callback = stm32_dfsdm_audio_dma_buffer_done; + desc->callback_param = indio_dev; + + cookie = dmaengine_submit(desc); + ret = dma_submit_error(cookie); + if (ret) { + dmaengine_terminate_all(adc->dma_chan); + return ret; + } + + /* Issue pending DMA requests */ + dma_async_issue_pending(adc->dma_chan); + + return 0; +} + +static int stm32_dfsdm_postenable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + const struct iio_chan_spec *chan = &indio_dev->channels[0]; + int ret; + + /* Reset adc buffer index */ + adc->bufi = 0; + + ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); + if (ret < 0) + return ret; + + ret = stm32_dfsdm_start_conv(adc, chan, true); + if (ret) { + dev_err(&indio_dev->dev, "Can't start conversion\n"); + goto stop_dfsdm; + } + + if (adc->dma_chan) { + ret = stm32_dfsdm_adc_dma_start(indio_dev); + if (ret) { + dev_err(&indio_dev->dev, "Can't start DMA\n"); + goto err_stop_conv; + } + } + + return 0; + +err_stop_conv: + stm32_dfsdm_stop_conv(adc, chan); +stop_dfsdm: + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return ret; +} + +static int stm32_dfsdm_predisable(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + const struct iio_chan_spec *chan = &indio_dev->channels[0]; + + if (adc->dma_chan) + dmaengine_terminate_all(adc->dma_chan); + + stm32_dfsdm_stop_conv(adc, chan); + + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return 0; +} + +static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = { + .postenable = &stm32_dfsdm_postenable, + .predisable = &stm32_dfsdm_predisable, +}; + +/** + * stm32_dfsdm_get_buff_cb() - register a callback that will be called when + * DMA transfer period is achieved. + * + * @iio_dev: Handle to IIO device. + * @cb: Pointer to callback function: + * - data: pointer to data buffer + * - size: size in byte of the data buffer + * - private: pointer to consumer private structure. + * @private: Pointer to consumer private structure. + */ +int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev, + int (*cb)(const void *data, size_t size, + void *private), + void *private) +{ + struct stm32_dfsdm_adc *adc; + + if (!iio_dev) + return -EINVAL; + adc = iio_priv(iio_dev); + + adc->cb = cb; + adc->cb_priv = private; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb); + +/** + * stm32_dfsdm_release_buff_cb - unregister buffer callback + * + * @iio_dev: Handle to IIO device. + */ +int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev) +{ + struct stm32_dfsdm_adc *adc; + + if (!iio_dev) + return -EINVAL; + adc = iio_priv(iio_dev); + + adc->cb = NULL; + adc->cb_priv = NULL; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb); + +static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *res) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + long timeout; + int ret; + + reinit_completion(&adc->completion); + + adc->buffer = res; + + ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); + if (ret < 0) + return ret; + + ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1)); + if (ret < 0) + goto stop_dfsdm; + + ret = stm32_dfsdm_start_conv(adc, chan, false); + if (ret < 0) { + regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); + goto stop_dfsdm; + } + + timeout = wait_for_completion_interruptible_timeout(&adc->completion, + DFSDM_TIMEOUT); + + /* Mask IRQ for regular conversion achievement*/ + regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), + DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); + + if (timeout == 0) + ret = -ETIMEDOUT; + else if (timeout < 0) + ret = timeout; + else + ret = IIO_VAL_INT; + + stm32_dfsdm_stop_conv(adc, chan); + +stop_dfsdm: + stm32_dfsdm_stop_dfsdm(adc->dfsdm); + + return ret; +} + +static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; + struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel]; + unsigned int spi_freq; + int ret = -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + ret = stm32_dfsdm_set_osrs(fl, 0, val); + if (!ret) + adc->oversamp = val; + + return ret; + + case IIO_CHAN_INFO_SAMP_FREQ: + if (!val) + return -EINVAL; + + switch (ch->src) { + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL: + spi_freq = adc->dfsdm->spi_master_freq; + break; + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING: + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING: + spi_freq = adc->dfsdm->spi_master_freq / 2; + break; + default: + spi_freq = adc->spi_freq; + } + + if (spi_freq % val) + dev_warn(&indio_dev->dev, + "Sampling rate not accurate (%d)\n", + spi_freq / (spi_freq / val)); + + ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val)); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Not able to find parameter that match!\n"); + return ret; + } + adc->sample_freq = val; + + return 0; + } + + return -EINVAL; +} + +static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iio_hw_consumer_enable(adc->hwc); + if (ret < 0) { + dev_err(&indio_dev->dev, + "%s: IIO enable failed (channel %d)\n", + __func__, chan->channel); + return ret; + } + ret = stm32_dfsdm_single_conv(indio_dev, chan, val); + iio_hw_consumer_disable(adc->hwc); + if (ret < 0) { + dev_err(&indio_dev->dev, + "%s: Conversion failed (channel %d)\n", + __func__, chan->channel); + return ret; + } + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = adc->oversamp; + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SAMP_FREQ: + *val = adc->sample_freq; + + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static const struct iio_info stm32_dfsdm_info_audio = { + .hwfifo_set_watermark = stm32_dfsdm_set_watermark, + .read_raw = stm32_dfsdm_read_raw, + .write_raw = stm32_dfsdm_write_raw, +}; + +static const struct iio_info stm32_dfsdm_info_adc = { + .read_raw = stm32_dfsdm_read_raw, + .write_raw = stm32_dfsdm_write_raw, +}; + +static irqreturn_t stm32_dfsdm_irq(int irq, void *arg) +{ + struct stm32_dfsdm_adc *adc = arg; + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + struct regmap *regmap = adc->dfsdm->regmap; + unsigned int status, int_en; + + regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status); + regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en); + + if (status & DFSDM_ISR_REOCF_MASK) { + /* Read the data register clean the IRQ status */ + regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer); + complete(&adc->completion); + } + + if (status & DFSDM_ISR_ROVRF_MASK) { + if (int_en & DFSDM_CR2_ROVRIE_MASK) + dev_warn(&indio_dev->dev, "Overrun detected\n"); + regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id), + DFSDM_ICR_CLRROVRF_MASK, + DFSDM_ICR_CLRROVRF_MASK); + } + + return IRQ_HANDLED; +} + +/* + * Define external info for SPI Frequency and audio sampling rate that can be + * configured by ASoC driver through consumer.h API + */ +static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = { + /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */ + { + .name = "spi_clk_freq", + .shared = IIO_SHARED_BY_TYPE, + .read = dfsdm_adc_audio_get_spiclk, + .write = dfsdm_adc_audio_set_spiclk, + }, + {}, +}; + +static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + + if (adc->dma_chan) { + dma_free_coherent(adc->dma_chan->device->dev, + DFSDM_DMA_BUFFER_SIZE, + adc->rx_buf, adc->dma_buf); + dma_release_channel(adc->dma_chan); + } +} + +static int stm32_dfsdm_dma_request(struct device *dev, + struct iio_dev *indio_dev) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct dma_slave_config config = { + .src_addr = (dma_addr_t)adc->dfsdm->phys_base + + DFSDM_RDATAR(adc->fl_id), + .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, + }; + int ret; + + adc->dma_chan = dma_request_chan(dev, "rx"); + if (IS_ERR(adc->dma_chan)) { + int ret = PTR_ERR(adc->dma_chan); + + adc->dma_chan = NULL; + return ret; + } + + adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, + DFSDM_DMA_BUFFER_SIZE, + &adc->dma_buf, GFP_KERNEL); + if (!adc->rx_buf) { + ret = -ENOMEM; + goto err_release; + } + + 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, DFSDM_DMA_BUFFER_SIZE, + adc->rx_buf, adc->dma_buf); +err_release: + dma_release_channel(adc->dma_chan); + + return ret; +} + +static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, + struct iio_chan_spec *ch) +{ + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int ret; + + ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch); + if (ret < 0) + return ret; + + ch->type = IIO_VOLTAGE; + ch->indexed = 1; + + /* + * IIO_CHAN_INFO_RAW: used to compute regular conversion + * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling + */ + ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); + ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO); + + if (adc->dev_data->type == DFSDM_AUDIO) { + ch->ext_info = dfsdm_adc_audio_ext_info; + } else { + ch->scan_type.shift = 8; + } + ch->scan_type.sign = 's'; + ch->scan_type.realbits = 24; + ch->scan_type.storagebits = 32; + + return stm32_dfsdm_chan_configure(adc->dfsdm, + &adc->dfsdm->ch_list[ch->channel]); +} + +static int stm32_dfsdm_audio_init(struct device *dev, struct iio_dev *indio_dev) +{ + struct iio_chan_spec *ch; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + struct stm32_dfsdm_channel *d_ch; + int ret; + + indio_dev->modes |= INDIO_BUFFER_SOFTWARE; + indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops; + + ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL); + if (!ch) + return -ENOMEM; + + ch->scan_index = 0; + + ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch); + if (ret < 0) { + dev_err(&indio_dev->dev, "Channels init failed\n"); + return ret; + } + ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ); + + d_ch = &adc->dfsdm->ch_list[ch->channel]; + if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) + adc->spi_freq = adc->dfsdm->spi_master_freq; + + indio_dev->num_channels = 1; + indio_dev->channels = ch; + + return stm32_dfsdm_dma_request(dev, indio_dev); +} + +static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev) +{ + struct iio_chan_spec *ch; + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); + int num_ch; + int ret, chan_idx; + + adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; + ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0, + adc->oversamp); + if (ret < 0) + return ret; + + num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, + "st,adc-channels"); + if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) { + dev_err(&indio_dev->dev, "Bad st,adc-channels\n"); + return num_ch < 0 ? num_ch : -EINVAL; + } + + /* Bind to SD modulator IIO device */ + adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev); + if (IS_ERR(adc->hwc)) + return -EPROBE_DEFER; + + ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch), + GFP_KERNEL); + if (!ch) + return -ENOMEM; + + for (chan_idx = 0; chan_idx < num_ch; chan_idx++) { + ch[chan_idx].scan_index = chan_idx; + ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]); + if (ret < 0) { + dev_err(&indio_dev->dev, "Channels init failed\n"); + return ret; + } + } + + indio_dev->num_channels = num_ch; + indio_dev->channels = ch; + + init_completion(&adc->completion); + + return 0; +} + +static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = { + .type = DFSDM_IIO, + .init = stm32_dfsdm_adc_init, +}; + +static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = { + .type = DFSDM_AUDIO, + .init = stm32_dfsdm_audio_init, +}; + +static const struct of_device_id stm32_dfsdm_adc_match[] = { + { + .compatible = "st,stm32-dfsdm-adc", + .data = &stm32h7_dfsdm_adc_data, + }, + { + .compatible = "st,stm32-dfsdm-dmic", + .data = &stm32h7_dfsdm_audio_data, + }, + {} +}; + +static int stm32_dfsdm_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_dfsdm_adc *adc; + struct device_node *np = dev->of_node; + const struct stm32_dfsdm_dev_data *dev_data; + struct iio_dev *iio; + char *name; + int ret, irq, val; + + dev_data = of_device_get_match_data(dev); + iio = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!iio) { + dev_err(dev, "%s: Failed to allocate IIO\n", __func__); + return -ENOMEM; + } + + adc = iio_priv(iio); + adc->dfsdm = dev_get_drvdata(dev->parent); + + iio->dev.parent = dev; + iio->dev.of_node = np; + iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + + platform_set_drvdata(pdev, adc); + + ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id); + if (ret != 0 || adc->fl_id >= adc->dfsdm->num_fls) { + dev_err(dev, "Missing or bad reg property\n"); + return -EINVAL; + } + + name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL); + if (!name) + return -ENOMEM; + if (dev_data->type == DFSDM_AUDIO) { + iio->info = &stm32_dfsdm_info_audio; + snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id); + } else { + iio->info = &stm32_dfsdm_info_adc; + snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id); + } + iio->name = name; + + /* + * In a first step IRQs generated for channels are not treated. + * So IRQ associated to filter instance 0 is dedicated to the Filter 0. + */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + if (irq != -EPROBE_DEFER) + dev_err(dev, "Failed to get IRQ: %d\n", irq); + return irq; + } + + ret = devm_request_irq(dev, irq, stm32_dfsdm_irq, + 0, pdev->name, adc); + if (ret < 0) { + dev_err(dev, "Failed to request IRQ\n"); + return ret; + } + + ret = of_property_read_u32(dev->of_node, "st,filter-order", &val); + if (ret < 0) { + dev_err(dev, "Failed to set filter order\n"); + return ret; + } + + adc->dfsdm->fl_list[adc->fl_id].ford = val; + + ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val); + if (!ret) + adc->dfsdm->fl_list[adc->fl_id].sync_mode = val; + + adc->dev_data = dev_data; + ret = dev_data->init(dev, iio); + if (ret < 0) + return ret; + + ret = iio_device_register(iio); + if (ret < 0) + goto err_cleanup; + + if (dev_data->type == DFSDM_AUDIO) { + ret = of_platform_populate(np, NULL, NULL, dev); + if (ret < 0) { + dev_err(dev, "Failed to find an audio DAI\n"); + goto err_unregister; + } + } + + return 0; + +err_unregister: + iio_device_unregister(iio); +err_cleanup: + stm32_dfsdm_dma_release(iio); + + return ret; +} + +static int stm32_dfsdm_adc_remove(struct platform_device *pdev) +{ + struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev); + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + + if (adc->dev_data->type == DFSDM_AUDIO) + of_platform_depopulate(&pdev->dev); + iio_device_unregister(indio_dev); + stm32_dfsdm_dma_release(indio_dev); + + return 0; +} + +static struct platform_driver stm32_dfsdm_adc_driver = { + .driver = { + .name = "stm32-dfsdm-adc", + .of_match_table = stm32_dfsdm_adc_match, + }, + .probe = stm32_dfsdm_adc_probe, + .remove = stm32_dfsdm_adc_remove, +}; +module_platform_driver(stm32_dfsdm_adc_driver); + +MODULE_DESCRIPTION("STM32 sigma delta ADC"); +MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); +MODULE_LICENSE("GPL v2"); |