From: Freeman Liu <freeman.liu@xxxxxxxxxxxxxx> 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 */ +#define SC27XX_ADC_TO_VOLTAGE(volt0, volt1, adc0, adc1, value) \ + ({ \ + 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 = { + 4200, 3310, + 3600, 2832, +}; + +static struct sc27xx_adc_linear_graph small_scale_graph = { + 1000, 3413, + 100, 341, +}; + +static int sc27xx_adc_2731_ratio(u32 channel, int scale) +{ + 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; + 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]; + 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); + 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; + 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 + * 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"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html