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path: root/drivers/iio/adc/rcar-gyroadc.c
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Diffstat (limited to 'drivers/iio/adc/rcar-gyroadc.c')
-rw-r--r--drivers/iio/adc/rcar-gyroadc.c631
1 files changed, 631 insertions, 0 deletions
diff --git a/drivers/iio/adc/rcar-gyroadc.c b/drivers/iio/adc/rcar-gyroadc.c
new file mode 100644
index 000000000..f3a966ab3
--- /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 *clk;
+ 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->clk) / 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 = {
+ .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 = -1, 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 = (uintptr_t)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;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * 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", &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 -EINVAL;
+ }
+ }
+
+ /* 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 -EINVAL;
+ }
+
+ /* 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)
+{
+ 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->clk = devm_clk_get(dev, "fck");
+ if (IS_ERR(priv->clk)) {
+ ret = PTR_ERR(priv->clk);
+ 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_device_get_match_data(&pdev->dev);
+
+ 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->clk);
+ 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->clk);
+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->clk);
+ 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 22:18:00 +0000