Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-17 01:22:07 +00:00
Code Issues Packages Projects Releases Wiki Activity
d85d71dd1a
linux/drivers/iio/adc/rcar-gyroadc.c
Jonathan Cameron db9c6c2ec4 iio: adc: rcar-gyroadc: Use pm_runtime_resume_and_get() and check in probe() 
1 instance found using coccicheck script under review at:
https://lore.kernel.org/lkml/20210427141946.2478411-1-Julia.Lawall@inria.fr/
The other instance changed did not check for failure of the
pm_runtime_get_sync() so that is added.

Note the remaining pm_runtime_get_sync() call is left alone because it
is not obvious what to do on failure to power up in remove()

This is a prequel to taking a closer look at the runtime pm in IIO drivers
in general.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210509113354.660190-29-jic23@kernel.org
2021-05-17 13:54:26 +01:00

622 lines
15 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0+
/*
* Renesas R-Car GyroADC driver
*
* Copyright 2016 Marek Vasut <marek.vasut@gmail.com>
*/
#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;
if (on) {
return pm_runtime_resume_and_get(dev);
} else {
pm_runtime_mark_last_busy(dev);
return pm_runtime_put_autosuspend(dev);
}
}
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 \"%pOFn\".",
child);
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:
goto err_e_inval;
}
/*
* 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 \"%pOFn\".\n",
child);
goto err_of_node_put;
}
/* Channel number is too high. */
if (reg >= num_channels) {
dev_err(dev,
"Only %i channels supported with %pOFn, but reg = <%i>.\n",
num_channels, child, reg);
goto err_e_inval;
}
}
/* 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);
goto err_e_inval;
}
/* 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);
ret = PTR_ERR(vref);
goto err_of_node_put;
}
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) {
of_node_put(child);
break;
}
}
if (first) {
dev_err(dev, "No valid ADC channels found, aborting.\n");
return -EINVAL;
}
return 0;
err_e_inval:
ret = -EINVAL;
err_of_node_put:
of_node_put(child);
return ret;
}
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;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
if (!indio_dev)
return -ENOMEM;
priv = iio_priv(indio_dev);
priv->dev = dev;
priv->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->regs))
return PTR_ERR(priv->regs);
priv->clk = devm_clk_get(dev, "fck");
if (IS_ERR(priv->clk))
return dev_err_probe(dev, PTR_ERR(priv->clk),
"Failed to get IF clock\n");
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->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);
ret = pm_runtime_resume_and_get(dev);
if (ret)
goto err_power_up;
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);
err_power_up:
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");
Reference in New Issue View Git Blame Copy Permalink