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linux/drivers/iio/adc/rcar-gyroadc.c
Uwe Kleine-König e785bace1a iio: adc: rcar-gyroadc: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919174931.1417681-20-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2023-09-23 15:06:54 +01:00

617 lines
15 KiB
C
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// 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[] __maybe_unused = {
/* 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 = (uintptr_t)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 void 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);
}
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;
}
static const struct dev_pm_ops rcar_gyroadc_pm_ops = {
RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)
};
static struct platform_driver rcar_gyroadc_driver = {
.probe = rcar_gyroadc_probe,
.remove_new = rcar_gyroadc_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = rcar_gyroadc_match,
.pm = pm_ptr(&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");
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