diff options
author | Marek Vasut <marek.vasut+renesas@gmail.com> | 2017-01-28 00:08:37 +0100 |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2017-01-28 11:33:53 +0000 |
commit | 059c53b3232960cfd38cc46de0a7bedd642021f5 (patch) | |
tree | 6a217ac42039db5013c4350b867c8378d50fed2f /drivers | |
parent | ec2ef15335547d6b96dcfb92e2dcebe08e156bc2 (diff) |
iio: adc: Add Renesas GyroADC driver
Add IIO driver for the Renesas RCar GyroADC block. This block is a
simple 4/8-channel ADC which samples 12/15/24 bits of data every
cycle from all channels.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/iio/adc/Kconfig | 13 | ||||
-rw-r--r-- | drivers/iio/adc/Makefile | 1 | ||||
-rw-r--r-- | drivers/iio/adc/rcar-gyroadc.c | 631 |
3 files changed, 645 insertions, 0 deletions
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 1a73e03defac..5f395d4983ed 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -458,6 +458,19 @@ config QCOM_SPMI_VADC To compile this driver as a module, choose M here: the module will be called qcom-spmi-vadc. +config RCAR_GYRO_ADC + tristate "Renesas R-Car GyroADC driver" + depends on ARCH_RCAR_GEN2 || (ARM && COMPILE_TEST) + help + Say yes here to build support for the GyroADC found in Renesas + R-Car Gen2 SoCs. This block is a simple SPI offload engine for + reading data out of attached compatible ADCs in a round-robin + fashion. Up to 4 or 8 ADC channels are supported by this block, + depending on which ADCs are attached. + + To compile this driver as a module, choose M here: the + module will be called rcar-gyroadc. + config ROCKCHIP_SARADC tristate "Rockchip SARADC driver" depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST) diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 9475fd572e5b..d27f8475712e 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_NAU7802) += nau7802.o obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o +obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o obj-$(CONFIG_STX104) += stx104.o obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o diff --git a/drivers/iio/adc/rcar-gyroadc.c b/drivers/iio/adc/rcar-gyroadc.c new file mode 100644 index 000000000000..0c44f72c32a8 --- /dev/null +++ b/drivers/iio/adc/rcar-gyroadc.c @@ -0,0 +1,631 @@ +/* + * Renesas R-Car GyroADC driver + * + * Copyright 2016 Marek Vasut <marek.vasut@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/regulator/consumer.h> +#include <linux/of_platform.h> +#include <linux/err.h> +#include <linux/pm_runtime.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> + +#define DRIVER_NAME "rcar-gyroadc" + +/* GyroADC registers. */ +#define RCAR_GYROADC_MODE_SELECT 0x00 +#define RCAR_GYROADC_MODE_SELECT_1_MB88101A 0x0 +#define RCAR_GYROADC_MODE_SELECT_2_ADCS7476 0x1 +#define RCAR_GYROADC_MODE_SELECT_3_MAX1162 0x3 + +#define RCAR_GYROADC_START_STOP 0x04 +#define RCAR_GYROADC_START_STOP_START BIT(0) + +#define RCAR_GYROADC_CLOCK_LENGTH 0x08 +#define RCAR_GYROADC_1_25MS_LENGTH 0x0c + +#define RCAR_GYROADC_REALTIME_DATA(ch) (0x10 + ((ch) * 4)) +#define RCAR_GYROADC_100MS_ADDED_DATA(ch) (0x30 + ((ch) * 4)) +#define RCAR_GYROADC_10MS_AVG_DATA(ch) (0x50 + ((ch) * 4)) + +#define RCAR_GYROADC_FIFO_STATUS 0x70 +#define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch) BIT(0 + (4 * (ch))) +#define RCAR_GYROADC_FIFO_STATUS_FULL(ch) BIT(1 + (4 * (ch))) +#define RCAR_GYROADC_FIFO_STATUS_ERROR(ch) BIT(2 + (4 * (ch))) + +#define RCAR_GYROADC_INTR 0x74 +#define RCAR_GYROADC_INTR_INT BIT(0) + +#define RCAR_GYROADC_INTENR 0x78 +#define RCAR_GYROADC_INTENR_INTEN BIT(0) + +#define RCAR_GYROADC_SAMPLE_RATE 800 /* Hz */ + +#define RCAR_GYROADC_RUNTIME_PM_DELAY_MS 2000 + +enum rcar_gyroadc_model { + RCAR_GYROADC_MODEL_DEFAULT, + RCAR_GYROADC_MODEL_R8A7792, +}; + +struct rcar_gyroadc { + struct device *dev; + void __iomem *regs; + struct clk *iclk; + struct regulator *vref[8]; + unsigned int num_channels; + enum rcar_gyroadc_model model; + unsigned int mode; + unsigned int sample_width; +}; + +static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv) +{ + const unsigned long clk_mhz = clk_get_rate(priv->iclk) / 1000000; + const unsigned long clk_mul = + (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5; + unsigned long clk_len = clk_mhz * clk_mul; + + /* + * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014, + * page 77-7, clock length must be even number. If it's odd number, + * add one. + */ + if (clk_len & 1) + clk_len++; + + /* Stop the GyroADC. */ + writel(0, priv->regs + RCAR_GYROADC_START_STOP); + + /* Disable IRQ on V2H. */ + if (priv->model == RCAR_GYROADC_MODEL_R8A7792) + writel(0, priv->regs + RCAR_GYROADC_INTENR); + + /* Set mode and timing. */ + writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT); + writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH); + writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH); +} + +static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv) +{ + /* Start sampling. */ + writel(RCAR_GYROADC_START_STOP_START, + priv->regs + RCAR_GYROADC_START_STOP); + + /* + * Wait for the first conversion to complete. This is longer than + * the 1.25 mS in the datasheet because 1.25 mS is not enough for + * the hardware to deliver the first sample and the hardware does + * then return zeroes instead of valid data. + */ + mdelay(3); +} + +static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv) +{ + /* Stop the GyroADC. */ + writel(0, priv->regs + RCAR_GYROADC_START_STOP); +} + +#define RCAR_GYROADC_CHAN(_idx) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (_idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ +} + +static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = { + RCAR_GYROADC_CHAN(0), + RCAR_GYROADC_CHAN(1), + RCAR_GYROADC_CHAN(2), + RCAR_GYROADC_CHAN(3), +}; + +static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = { + RCAR_GYROADC_CHAN(0), + RCAR_GYROADC_CHAN(1), + RCAR_GYROADC_CHAN(2), + RCAR_GYROADC_CHAN(3), + RCAR_GYROADC_CHAN(4), + RCAR_GYROADC_CHAN(5), + RCAR_GYROADC_CHAN(6), + RCAR_GYROADC_CHAN(7), +}; + +static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = { + RCAR_GYROADC_CHAN(0), + RCAR_GYROADC_CHAN(1), + RCAR_GYROADC_CHAN(2), + RCAR_GYROADC_CHAN(3), + RCAR_GYROADC_CHAN(4), + RCAR_GYROADC_CHAN(5), + RCAR_GYROADC_CHAN(6), + RCAR_GYROADC_CHAN(7), +}; + +static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on) +{ + struct device *dev = priv->dev; + int ret; + + if (on) { + ret = pm_runtime_get_sync(dev); + if (ret < 0) + pm_runtime_put_noidle(dev); + } else { + pm_runtime_mark_last_busy(dev); + ret = pm_runtime_put_autosuspend(dev); + } + + return ret; +} + +static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct rcar_gyroadc *priv = iio_priv(indio_dev); + struct regulator *consumer; + unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel); + unsigned int vref; + int ret; + + /* + * MB88101 is special in that it has only single regulator for + * all four channels. + */ + if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) + consumer = priv->vref[0]; + else + consumer = priv->vref[chan->channel]; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type != IIO_VOLTAGE) + return -EINVAL; + + /* Channel not connected. */ + if (!consumer) + return -EINVAL; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + + ret = rcar_gyroadc_set_power(priv, true); + if (ret < 0) { + iio_device_release_direct_mode(indio_dev); + return ret; + } + + *val = readl(priv->regs + datareg); + *val &= BIT(priv->sample_width) - 1; + + ret = rcar_gyroadc_set_power(priv, false); + iio_device_release_direct_mode(indio_dev); + if (ret < 0) + return ret; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* Channel not connected. */ + if (!consumer) + return -EINVAL; + + vref = regulator_get_voltage(consumer); + *val = vref / 1000; + *val2 = 1 << priv->sample_width; + + return IIO_VAL_FRACTIONAL; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = RCAR_GYROADC_SAMPLE_RATE; + + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev, + unsigned int reg, unsigned int writeval, + unsigned int *readval) +{ + struct rcar_gyroadc *priv = iio_priv(indio_dev); + unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS; + + if (readval == NULL) + return -EINVAL; + + if (reg % 4) + return -EINVAL; + + /* Handle the V2H case with extra interrupt block. */ + if (priv->model == RCAR_GYROADC_MODEL_R8A7792) + maxreg = RCAR_GYROADC_INTENR; + + if (reg > maxreg) + return -EINVAL; + + *readval = readl(priv->regs + reg); + + return 0; +} + +static const struct iio_info rcar_gyroadc_iio_info = { + .driver_module = THIS_MODULE, + .read_raw = rcar_gyroadc_read_raw, + .debugfs_reg_access = rcar_gyroadc_reg_access, +}; + +static const struct of_device_id rcar_gyroadc_match[] = { + { + /* R-Car compatible GyroADC */ + .compatible = "renesas,rcar-gyroadc", + .data = (void *)RCAR_GYROADC_MODEL_DEFAULT, + }, { + /* R-Car V2H specialty with interrupt registers. */ + .compatible = "renesas,r8a7792-gyroadc", + .data = (void *)RCAR_GYROADC_MODEL_R8A7792, + }, { + /* sentinel */ + } +}; + +MODULE_DEVICE_TABLE(of, rcar_gyroadc_match); + +static const struct of_device_id rcar_gyroadc_child_match[] = { + /* Mode 1 ADCs */ + { + .compatible = "fujitsu,mb88101a", + .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A, + }, + /* Mode 2 ADCs */ + { + .compatible = "ti,adcs7476", + .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, + }, { + .compatible = "ti,adc121", + .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, + }, { + .compatible = "adi,ad7476", + .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476, + }, + /* Mode 3 ADCs */ + { + .compatible = "maxim,max1162", + .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, + }, { + .compatible = "maxim,max11100", + .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162, + }, + { /* sentinel */ } +}; + +static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev) +{ + const struct of_device_id *of_id; + const struct iio_chan_spec *channels; + struct rcar_gyroadc *priv = iio_priv(indio_dev); + struct device *dev = priv->dev; + struct device_node *np = dev->of_node; + struct device_node *child; + struct regulator *vref; + unsigned int reg; + unsigned int adcmode, childmode; + unsigned int sample_width; + unsigned int num_channels; + int ret, first = 1; + + for_each_child_of_node(np, child) { + of_id = of_match_node(rcar_gyroadc_child_match, child); + if (!of_id) { + dev_err(dev, "Ignoring unsupported ADC \"%s\".", + child->name); + continue; + } + + childmode = (unsigned int)of_id->data; + switch (childmode) { + case RCAR_GYROADC_MODE_SELECT_1_MB88101A: + sample_width = 12; + channels = rcar_gyroadc_iio_channels_1; + num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1); + break; + case RCAR_GYROADC_MODE_SELECT_2_ADCS7476: + sample_width = 15; + channels = rcar_gyroadc_iio_channels_2; + num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2); + break; + case RCAR_GYROADC_MODE_SELECT_3_MAX1162: + sample_width = 16; + channels = rcar_gyroadc_iio_channels_3; + num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3); + break; + } + + /* + * MB88101 is special in that it's only a single chip taking + * up all the CHS lines. Thus, the DT binding is also special + * and has no reg property. If we run into such ADC, handle + * it here. + */ + if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) { + reg = 0; + } else { + ret = of_property_read_u32(child, "reg", ®); + if (ret) { + dev_err(dev, + "Failed to get child reg property of ADC \"%s\".\n", + child->name); + return ret; + } + + /* Channel number is too high. */ + if (reg >= num_channels) { + dev_err(dev, + "Only %i channels supported with %s, but reg = <%i>.\n", + num_channels, child->name, reg); + return ret; + } + } + + /* Child node selected different mode than the rest. */ + if (!first && (adcmode != childmode)) { + dev_err(dev, + "Channel %i uses different ADC mode than the rest.\n", + reg); + return ret; + } + + /* Channel is valid, grab the regulator. */ + dev->of_node = child; + vref = devm_regulator_get(dev, "vref"); + dev->of_node = np; + if (IS_ERR(vref)) { + dev_dbg(dev, "Channel %i 'vref' supply not connected.\n", + reg); + return PTR_ERR(vref); + } + + priv->vref[reg] = vref; + + if (!first) + continue; + + /* First child node which passed sanity tests. */ + adcmode = childmode; + first = 0; + + priv->num_channels = num_channels; + priv->mode = childmode; + priv->sample_width = sample_width; + + indio_dev->channels = channels; + indio_dev->num_channels = num_channels; + + /* + * MB88101 is special and we only have one such device + * attached to the GyroADC at a time, so if we found it, + * we can stop parsing here. + */ + if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) + break; + } + + if (first) { + dev_err(dev, "No valid ADC channels found, aborting.\n"); + return -EINVAL; + } + + return 0; +} + +static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev) +{ + struct rcar_gyroadc *priv = iio_priv(indio_dev); + unsigned int i; + + for (i = 0; i < priv->num_channels; i++) { + if (!priv->vref[i]) + continue; + + regulator_disable(priv->vref[i]); + } +} + +static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev) +{ + struct rcar_gyroadc *priv = iio_priv(indio_dev); + struct device *dev = priv->dev; + unsigned int i; + int ret; + + for (i = 0; i < priv->num_channels; i++) { + if (!priv->vref[i]) + continue; + + ret = regulator_enable(priv->vref[i]); + if (ret) { + dev_err(dev, "Failed to enable regulator %i (ret=%i)\n", + i, ret); + goto err; + } + } + + return 0; + +err: + rcar_gyroadc_deinit_supplies(indio_dev); + return ret; +} + +static int rcar_gyroadc_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id = + of_match_device(rcar_gyroadc_match, &pdev->dev); + struct device *dev = &pdev->dev; + struct rcar_gyroadc *priv; + struct iio_dev *indio_dev; + struct resource *mem; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (!indio_dev) { + dev_err(dev, "Failed to allocate IIO device.\n"); + return -ENOMEM; + } + + priv = iio_priv(indio_dev); + priv->dev = dev; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->regs = devm_ioremap_resource(dev, mem); + if (IS_ERR(priv->regs)) + return PTR_ERR(priv->regs); + + priv->iclk = devm_clk_get(dev, "if"); + if (IS_ERR(priv->iclk)) { + ret = PTR_ERR(priv->iclk); + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret); + return ret; + } + + ret = rcar_gyroadc_parse_subdevs(indio_dev); + if (ret) + return ret; + + ret = rcar_gyroadc_init_supplies(indio_dev); + if (ret) + return ret; + + priv->model = (enum rcar_gyroadc_model)of_id->data; + + platform_set_drvdata(pdev, indio_dev); + + indio_dev->name = DRIVER_NAME; + indio_dev->dev.parent = dev; + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->info = &rcar_gyroadc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = clk_prepare_enable(priv->iclk); + if (ret) { + dev_err(dev, "Could not prepare or enable the IF clock.\n"); + goto err_clk_if_enable; + } + + pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS); + pm_runtime_use_autosuspend(dev); + pm_runtime_enable(dev); + + pm_runtime_get_sync(dev); + rcar_gyroadc_hw_init(priv); + rcar_gyroadc_hw_start(priv); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(dev, "Couldn't register IIO device.\n"); + goto err_iio_device_register; + } + + pm_runtime_put_sync(dev); + + return 0; + +err_iio_device_register: + rcar_gyroadc_hw_stop(priv); + pm_runtime_put_sync(dev); + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + clk_disable_unprepare(priv->iclk); +err_clk_if_enable: + rcar_gyroadc_deinit_supplies(indio_dev); + + return ret; +} + +static int rcar_gyroadc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct rcar_gyroadc *priv = iio_priv(indio_dev); + struct device *dev = priv->dev; + + iio_device_unregister(indio_dev); + pm_runtime_get_sync(dev); + rcar_gyroadc_hw_stop(priv); + pm_runtime_put_sync(dev); + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + clk_disable_unprepare(priv->iclk); + rcar_gyroadc_deinit_supplies(indio_dev); + + return 0; +} + +#if defined(CONFIG_PM) +static int rcar_gyroadc_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct rcar_gyroadc *priv = iio_priv(indio_dev); + + rcar_gyroadc_hw_stop(priv); + + return 0; +} + +static int rcar_gyroadc_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct rcar_gyroadc *priv = iio_priv(indio_dev); + + rcar_gyroadc_hw_start(priv); + + return 0; +} +#endif + +static const struct dev_pm_ops rcar_gyroadc_pm_ops = { + SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL) +}; + +static struct platform_driver rcar_gyroadc_driver = { + .probe = rcar_gyroadc_probe, + .remove = rcar_gyroadc_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = rcar_gyroadc_match, + .pm = &rcar_gyroadc_pm_ops, + }, +}; + +module_platform_driver(rcar_gyroadc_driver); + +MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); +MODULE_DESCRIPTION("Renesas R-Car GyroADC driver"); +MODULE_LICENSE("GPL"); |