> From: Freeman Liu <freeman.liu@xxxxxxxxxxxxxx> some comments below > The Spreadtrum SC27XX PMICs ADC controller contains 32 channels, > which is used to sample voltages with 12 bits conversion. > > Signed-off-by: Freeman Liu <freeman.liu@xxxxxxxxxxxxxx> > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> > --- > drivers/iio/adc/Kconfig | 10 + > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/sc27xx_adc.c | 558 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 569 insertions(+) > create mode 100644 drivers/iio/adc/sc27xx_adc.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 9da7907..985b73e 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -621,6 +621,16 @@ config ROCKCHIP_SARADC > To compile this driver as a module, choose M here: the > module will be called rockchip_saradc. > > +config SC27XX_ADC > + tristate "Spreadtrum SC27xx series PMICs ADC" > + depends on MFD_SC27XX_PMIC || COMPILE_TEST > + help > + Say yes here to build support for the integrated ADC inside the > + Spreadtrum SC27xx series PMICs. > + > + This driver can also be built as a module. If so, the module > + will be called sc27xx_adc. > + > config SPEAR_ADC > tristate "ST SPEAr ADC" > depends on PLAT_SPEAR || COMPILE_TEST > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 28a9423..03db7b5 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -59,6 +59,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o > obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o > obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o > obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o > +obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o > obj-$(CONFIG_SPEAR_ADC) += spear_adc.o > obj-$(CONFIG_STX104) += stx104.o > obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o > diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c > new file mode 100644 > index 0000000..d74310a > --- /dev/null > +++ b/drivers/iio/adc/sc27xx_adc.c > @@ -0,0 +1,558 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (C) 2018 Spreadtrum Communications Inc. > + > +#include <linux/hwspinlock.h> > +#include <linux/iio/iio.h> > +#include <linux/interrupt.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > + > +/* PMIC global registers definition */ > +#define SC27XX_MODULE_EN 0xc08 > +#define SC27XX_MODULE_ADC_EN BIT(5) > +#define SC27XX_ARM_CLK_EN 0xc10 > +#define SC27XX_CLK_ADC_EN BIT(5) > +#define SC27XX_CLK_ADC_CLK_EN BIT(6) > + > +/* ADC controller registers definition */ > +#define SC27XX_ADC_CTL 0x0 > +#define SC27XX_ADC_CH_CFG 0x4 > +#define SC27XX_ADC_DATA 0x4c > +#define SC27XX_ADC_INT_EN 0x50 > +#define SC27XX_ADC_INT_CLR 0x54 > +#define SC27XX_ADC_INT_STS 0x58 > +#define SC27XX_ADC_INT_RAW 0x5c > + > +/* Bits and mask definition for SC27XX_ADC_CTL register */ > +#define SC27XX_ADC_EN BIT(0) > +#define SC27XX_ADC_CHN_RUN BIT(1) > +#define SC27XX_ADC_12BIT_MODE BIT(2) > +#define SC27XX_ADC_RUN_NUM_MASK GENMASK(7, 4) > +#define SC27XX_ADC_RUN_NUM_SHIFT 4 > + > +/* Bits and mask definition for SC27XX_ADC_CH_CFG register */ > +#define SC27XX_ADC_CHN_ID_MASK GENMASK(4, 0) > +#define SC27XX_ADC_SCALE_MASK GENMASK(10, 8) > +#define SC27XX_ADC_SCALE_SHIFT 8 > + > +/* Bits definitions for SC27XX_ADC_INT_EN registers */ > +#define SC27XX_ADC_IRQ_EN BIT(0) > + > +/* Bits definitions for SC27XX_ADC_INT_CLR registers */ > +#define SC27XX_ADC_IRQ_CLR BIT(0) > + > +/* Mask definition for SC27XX_ADC_DATA register */ > +#define SC27XX_ADC_DATA_MASK GENMASK(11, 0) > + > +/* Timeout (ms) for the trylock of hardware spinlocks */ > +#define SC27XX_ADC_HWLOCK_TIMEOUT 5000 > + > +/* Maximum ADC channel number */ > +#define SC27XX_ADC_CHANNEL_MAX 32 > + > +/* ADC voltage ratio definition */ > +#define SC27XX_VOLT_RATIO(n, d) \ > + (((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d)) > +#define SC27XX_RATIO_NUMERATOR_OFFSET 16 > +#define SC27XX_RATIO_DENOMINATOR_MASK GENMASK(15, 0) > + > +/* Covert ADC values to voltage values */ Convert > +#define SC27XX_ADC_TO_VOLTAGE(volt0, volt1, adc0, adc1, value) \ I'd rather define a function than a macro for this > + ({ \ > + int tmp; \ > + tmp = (volt0) - (volt1); \ > + tmp = tmp * ((value) - (adc1)); \ > + tmp = tmp / ((adc0) - (adc1)); \ > + tmp = tmp + (volt1); \ > + if (tmp < 0) \ > + tmp = 0; \ > + \ > + tmp; \ > + }) > + > +struct sc27xx_adc_data { > + struct device *dev; > + struct regmap *regmap; > + /* > + * One hardware spinlock to synchronize between the multiple > + * subsystems which will access the unique ADC controller. > + */ > + struct hwspinlock *hwlock; > + struct completion completion; > + int channel_scale[SC27XX_ADC_CHANNEL_MAX]; > + int (*get_volt_ratio)(u32 channel, int scale); > + u32 base; > + int value; > + int irq; > +}; > + > +struct sc27xx_adc_linear_graph { > + int volt0; > + int adc0; > + int volt1; > + int adc1; > +}; > + > +/* > + * According to the datasheet, we can convert one ADC value to one voltage value > + * through 2 points in the linear graph. If the voltage is less than 1.2v, we > + * should use the small-scale graph, and if more than 1.2v, we should use the > + * big-scale graph. > + */ > +static struct sc27xx_adc_linear_graph big_scale_graph = { const > + 4200, 3310, > + 3600, 2832, > +}; > + > +static struct sc27xx_adc_linear_graph small_scale_graph = { const > + 1000, 3413, > + 100, 341, > +}; > + > +static int sc27xx_adc_2731_ratio(u32 channel, int scale) can scale be bool? or unsigned? why use u32 for channel? maybe u8 or just unsigned? > +{ > + switch (channel) { > + case 1: > + case 2: > + case 3: > + case 4: > + return scale ? SC27XX_VOLT_RATIO(400, 1025) : > + SC27XX_VOLT_RATIO(1, 1); > + case 5: > + return SC27XX_VOLT_RATIO(7, 29); > + case 6: > + return SC27XX_VOLT_RATIO(375, 9000); > + case 7: > + case 8: > + return scale ? SC27XX_VOLT_RATIO(100, 125) : > + SC27XX_VOLT_RATIO(1, 1); > + case 19: > + return SC27XX_VOLT_RATIO(1, 3); > + default: > + return SC27XX_VOLT_RATIO(1, 1); > + } > + return SC27XX_VOLT_RATIO(1, 1); > +} > + > +static int sc27xx_adc_read(struct sc27xx_adc_data *data, u32 channel, > + int scale, int *val) > +{ > + int ret; > + u32 tmp; > + > + reinit_completion(&data->completion); > + > + ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT); > + if (ret) { > + dev_err(data->dev, "timeout to get the hwspinlock\n"); > + return ret; > + } > + > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, > + SC27XX_ADC_EN, SC27XX_ADC_EN); > + if (ret) > + goto unlock_adc; > + > + /* Configure the channel id and scale */ > + tmp = (scale << SC27XX_ADC_SCALE_SHIFT) & SC27XX_ADC_SCALE_MASK; > + tmp |= channel & SC27XX_ADC_CHN_ID_MASK; > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG, > + SC27XX_ADC_CHN_ID_MASK | SC27XX_ADC_SCALE_MASK, > + tmp); > + if (ret) > + goto disable_adc; > + > + /* Select 12bit conversion mode, and only sample 1 time */ > + tmp = SC27XX_ADC_12BIT_MODE; > + tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK; this is still 0 > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, > + SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE, > + tmp); > + if (ret) > + goto disable_adc; > + > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, > + SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN); > + if (ret) > + goto disable_adc; > + > + wait_for_completion(&data->completion); > + > +disable_adc: > + regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, > + SC27XX_ADC_EN, 0); > +unlock_adc: > + hwspin_unlock_raw(data->hwlock); > + > + if (!ret) > + *val = data->value; > + > + return ret; > +} > + > +static irqreturn_t sc27xx_adc_isr(int irq, void *dev_id) > +{ > + struct sc27xx_adc_data *data = dev_id; > + int ret; > + > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR, > + SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR); > + if (ret) > + return IRQ_RETVAL(ret); > + > + ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, > + &data->value); > + if (ret) > + return IRQ_RETVAL(ret); > + > + data->value &= SC27XX_ADC_DATA_MASK; > + complete(&data->completion); > + > + return IRQ_HANDLED; > +} > + > +static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, > + u32 channel, int scale, > + u32 *div_numerator, u32 *div_denominator) > +{ > + u32 ratio = data->get_volt_ratio(channel, scale); > + > + *div_numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET; > + *div_denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK; > +} > + > +static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, u32 channel, > + int scale, int raw_adc) > +{ > + u32 numerator, denominator; > + u32 volt; > + > + /* > + * Convert ADC values to voltage values according to the linear graph, > + * and channel 5 and channel 1 has been calibrated, so we can just > + * return the voltage values calculated by the linear graph. But other > + * channels need be calculated to the real voltage values with the > + * voltage ratio. > + */ > + if (channel == 5) { > + return SC27XX_ADC_TO_VOLTAGE(big_scale_graph.volt0, > + big_scale_graph.volt1, > + big_scale_graph.adc0, > + big_scale_graph.adc1, > + raw_adc); > + } else if (channel == 1) { > + return SC27XX_ADC_TO_VOLTAGE(small_scale_graph.volt0, > + small_scale_graph.volt1, > + small_scale_graph.adc0, > + small_scale_graph.adc1, > + raw_adc); > + } else { > + volt = SC27XX_ADC_TO_VOLTAGE(small_scale_graph.volt0, > + small_scale_graph.volt1, > + small_scale_graph.adc0, > + small_scale_graph.adc1, > + raw_adc); > + } > + > + sc27xx_adc_volt_ratio(data, channel, scale, &numerator, &denominator); > + > + return (volt * denominator + numerator / 2) / numerator; > +} > + > +static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data, > + u32 channel, int scale, int *val) > +{ > + int ret, raw_adc; > + > + ret = sc27xx_adc_read(data, channel, scale, &raw_adc); > + if (ret) > + return ret; > + > + *val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc); > + return 0; > +} > + > +static int sc27xx_adc_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct sc27xx_adc_data *data = iio_priv(indio_dev); > + int scale = data->channel_scale[chan->channel]; channel_scale is accesses outside the mutex lock (see adc_write_raw() where it is locked) > + int ret, tmp; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + case IIO_CHAN_INFO_AVERAGE_RAW: > + mutex_lock(&indio_dev->mlock); > + ret = sc27xx_adc_read(data, chan->channel, scale, &tmp); move mutex_unlock() to here? and similar for the other cases > + if (ret) { > + mutex_unlock(&indio_dev->mlock); > + return ret; > + } > + > + *val = tmp; > + mutex_unlock(&indio_dev->mlock); > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_PROCESSED: > + mutex_lock(&indio_dev->mlock); > + ret = sc27xx_adc_read_processed(data, chan->channel, scale, > + &tmp); > + if (ret) { > + mutex_unlock(&indio_dev->mlock); > + return ret; > + } > + > + *val = tmp; > + mutex_unlock(&indio_dev->mlock); > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + mutex_lock(&indio_dev->mlock); > + *val = scale; > + mutex_unlock(&indio_dev->mlock); > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > +static int sc27xx_adc_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct sc27xx_adc_data *data = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + mutex_lock(&indio_dev->mlock); > + data->channel_scale[chan->channel] = val; this is strange, arbitraty numbers can be written here? what happens with val2? must be 0? > + mutex_unlock(&indio_dev->mlock); > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info sc27xx_info = { > + .read_raw = &sc27xx_adc_read_raw, > + .write_raw = &sc27xx_adc_write_raw, > +}; > + > +#define SC27XX_ADC_CHANNEL(index) { \ > + .type = IIO_VOLTAGE, \ > + .channel = index, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > + BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \ > + BIT(IIO_CHAN_INFO_PROCESSED) | \ > + BIT(IIO_CHAN_INFO_SCALE), \ > + .datasheet_name = "CH##index", \ > + .indexed = 1, \ > +} > + > +static const struct iio_chan_spec sc27xx_channels[] = { > + SC27XX_ADC_CHANNEL(0), > + SC27XX_ADC_CHANNEL(1), > + SC27XX_ADC_CHANNEL(2), > + SC27XX_ADC_CHANNEL(3), > + SC27XX_ADC_CHANNEL(4), > + SC27XX_ADC_CHANNEL(5), > + SC27XX_ADC_CHANNEL(6), > + SC27XX_ADC_CHANNEL(7), > + SC27XX_ADC_CHANNEL(8), > + SC27XX_ADC_CHANNEL(9), > + SC27XX_ADC_CHANNEL(10), > + SC27XX_ADC_CHANNEL(11), > + SC27XX_ADC_CHANNEL(12), > + SC27XX_ADC_CHANNEL(13), > + SC27XX_ADC_CHANNEL(14), > + SC27XX_ADC_CHANNEL(15), > + SC27XX_ADC_CHANNEL(16), > + SC27XX_ADC_CHANNEL(17), > + SC27XX_ADC_CHANNEL(18), > + SC27XX_ADC_CHANNEL(19), > + SC27XX_ADC_CHANNEL(20), > + SC27XX_ADC_CHANNEL(21), > + SC27XX_ADC_CHANNEL(22), > + SC27XX_ADC_CHANNEL(23), > + SC27XX_ADC_CHANNEL(24), > + SC27XX_ADC_CHANNEL(25), > + SC27XX_ADC_CHANNEL(26), > + SC27XX_ADC_CHANNEL(27), > + SC27XX_ADC_CHANNEL(28), > + SC27XX_ADC_CHANNEL(29), > + SC27XX_ADC_CHANNEL(30), > + SC27XX_ADC_CHANNEL(31), > +}; > + > +static int sc27xx_adc_enable(struct sc27xx_adc_data *data) > +{ > + int ret; > + > + ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN, > + SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN); > + if (ret) > + return ret; > + > + /* Enable ADC work clock and controller clock */ > + ret = regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN, > + SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, > + SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN); > + if (ret) > + return ret; > + > + ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN, > + SC27XX_ADC_IRQ_EN, SC27XX_ADC_IRQ_EN); > + if (ret) > + return ret; > + > + return regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR, > + SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR); > +} > + > +static void sc27xx_adc_disable(struct sc27xx_adc_data *data) > +{ > + regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN, > + SC27XX_ADC_IRQ_EN, 0); > + > + /* Disable ADC work clock and controller clock */ > + regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN, > + SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0); > + > + regmap_update_bits(data->regmap, SC27XX_MODULE_EN, > + SC27XX_MODULE_ADC_EN, 0); > +} > + > +static int sc27xx_adc_probe(struct platform_device *pdev) > +{ > + struct device_node *np = pdev->dev.of_node; > + struct sc27xx_adc_data *sc27xx_data; > + struct iio_dev *indio_dev; > + const void *data; > + int ret; > + > + data = of_device_get_match_data(&pdev->dev); > + if (!data) { > + dev_err(&pdev->dev, "failed to get match data\n"); > + return -EINVAL; > + } > + > + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*sc27xx_data)); > + if (!indio_dev) > + return -ENOMEM; > + > + sc27xx_data = iio_priv(indio_dev); > + > + sc27xx_data->regmap = dev_get_regmap(pdev->dev.parent, NULL); > + if (!sc27xx_data->regmap) { > + dev_err(&pdev->dev, "failed to get ADC regmap\n"); > + return -ENODEV; > + } > + > + ret = of_property_read_u32(np, "reg", &sc27xx_data->base); > + if (ret) { > + dev_err(&pdev->dev, "failed to get ADC base address\n"); > + return ret; > + } > + > + sc27xx_data->irq = platform_get_irq(pdev, 0); > + if (sc27xx_data->irq < 0) { > + dev_err(&pdev->dev, "failed to get ADC irq number\n"); > + return sc27xx_data->irq; > + } > + > + ret = of_hwspin_lock_get_id(np, 0); > + if (ret < 0) { > + dev_err(&pdev->dev, "failed to get hwspinlock id\n"); > + return ret; > + } > + > + sc27xx_data->hwlock = hwspin_lock_request_specific(ret); > + if (!sc27xx_data->hwlock) { > + dev_err(&pdev->dev, "failed to request hwspinlock\n"); > + return -ENXIO; > + } > + > + init_completion(&sc27xx_data->completion); > + > + /* > + * Different PMIC ADC controllers can have differnt channel voltage different > + * ratios, so we should save the implementation of getting voltage > + * ratio for corresponding PMIC ADC in the device data structure. > + */ > + sc27xx_data->get_volt_ratio = data; > + sc27xx_data->dev = &pdev->dev; > + > + ret = sc27xx_adc_enable(sc27xx_data); > + if (ret) { > + dev_err(&pdev->dev, "failed to enable ADC module\n"); > + goto free_hwlock; > + } > + > + ret = devm_request_threaded_irq(&pdev->dev, sc27xx_data->irq, NULL, > + sc27xx_adc_isr, IRQF_ONESHOT, > + pdev->name, sc27xx_data); > + if (ret) { > + dev_err(&pdev->dev, "failed to request ADC irq\n"); > + goto disable_adc; > + } > + > + indio_dev->dev.parent = &pdev->dev; > + indio_dev->name = dev_name(&pdev->dev); > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &sc27xx_info; > + indio_dev->channels = sc27xx_channels; > + indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels); > + ret = devm_iio_device_register(&pdev->dev, indio_dev); > + if (ret) { > + dev_err(&pdev->dev, "could not register iio (ADC)"); > + goto disable_adc; > + } > + > + platform_set_drvdata(pdev, indio_dev); > + return 0; > + > +disable_adc: > + sc27xx_adc_disable(sc27xx_data); > +free_hwlock: > + hwspin_lock_free(sc27xx_data->hwlock); > + return ret; > +} > + > +static int sc27xx_adc_remove(struct platform_device *pdev) > +{ > + struct iio_dev *indio_dev = platform_get_drvdata(pdev); > + struct sc27xx_adc_data *sc27xx_data = iio_priv(indio_dev); > + > + sc27xx_adc_disable(sc27xx_data); > + hwspin_lock_free(sc27xx_data->hwlock); > + return 0; > +} > + > +static const struct of_device_id sc27xx_adc_of_match[] = { > + { > + .compatible = "sprd,sc2731-adc", > + .data = (void *)&sc27xx_adc_2731_ratio, > + }, > + { } > +}; > + > +static struct platform_driver sc27xx_adc_driver = { > + .probe = sc27xx_adc_probe, > + .remove = sc27xx_adc_remove, > + .driver = { > + .name = "sc27xx-adc", > + .of_match_table = sc27xx_adc_of_match, > + }, > +}; > + > +module_platform_driver(sc27xx_adc_driver); > + > +MODULE_AUTHOR("Freeman Liu <freeman.liu@xxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html