linux/drivers/iio/adc/stm32-dfsdm-core.c
Uwe Kleine-König 259fbaecb7 iio: adc: stm32-dfsdm-core: 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/20230919174931.1417681-24-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2023-09-23 15:06:54 +01:00

522 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* This file is part the core part STM32 DFSDM driver
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "stm32-dfsdm.h"
/**
* struct stm32_dfsdm_dev_data - DFSDM compatible configuration data
* @ipid: DFSDM identification number. Used only if hardware provides identification registers
* @num_filters: DFSDM number of filters. Unused if identification registers are available
* @num_channels: DFSDM number of channels. Unused if identification registers are available
* @regmap_cfg: SAI register map configuration pointer
*/
struct stm32_dfsdm_dev_data {
u32 ipid;
unsigned int num_filters;
unsigned int num_channels;
const struct regmap_config *regmap_cfg;
};
#define STM32H7_DFSDM_NUM_FILTERS 4
#define STM32H7_DFSDM_NUM_CHANNELS 8
static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
{
if (reg < DFSDM_FILTER_BASE_ADR)
return false;
/*
* Mask is done on register to avoid to list registers of all
* filter instances.
*/
switch (reg & DFSDM_FILTER_REG_MASK) {
case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
return true;
}
return false;
}
static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = sizeof(u32),
.max_register = 0x2B8,
.volatile_reg = stm32_dfsdm_volatile_reg,
.fast_io = true,
};
static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
.num_filters = STM32H7_DFSDM_NUM_FILTERS,
.num_channels = STM32H7_DFSDM_NUM_CHANNELS,
.regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
};
static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = sizeof(u32),
.max_register = 0x7fc,
.volatile_reg = stm32_dfsdm_volatile_reg,
.fast_io = true,
};
static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
.ipid = STM32MP15_IPIDR_NUMBER,
.regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
};
struct dfsdm_priv {
struct platform_device *pdev; /* platform device */
struct stm32_dfsdm dfsdm; /* common data exported for all instances */
unsigned int spi_clk_out_div; /* SPI clkout divider value */
atomic_t n_active_ch; /* number of current active channels */
struct clk *clk; /* DFSDM clock */
struct clk *aclk; /* audio clock */
};
static inline struct dfsdm_priv *to_stm32_dfsdm_priv(struct stm32_dfsdm *dfsdm)
{
return container_of(dfsdm, struct dfsdm_priv, dfsdm);
}
static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
int ret;
ret = clk_prepare_enable(priv->clk);
if (ret || !priv->aclk)
return ret;
ret = clk_prepare_enable(priv->aclk);
if (ret)
clk_disable_unprepare(priv->clk);
return ret;
}
static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
clk_disable_unprepare(priv->aclk);
clk_disable_unprepare(priv->clk);
}
/**
* stm32_dfsdm_start_dfsdm - start global dfsdm interface.
*
* Enable interface if n_active_ch is not null.
* @dfsdm: Handle used to retrieve dfsdm context.
*/
int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
struct device *dev = &priv->pdev->dev;
unsigned int clk_div = priv->spi_clk_out_div, clk_src;
int ret;
if (atomic_inc_return(&priv->n_active_ch) == 1) {
ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
goto error_ret;
/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
clk_src = priv->aclk ? 1 : 0;
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTSRC_MASK,
DFSDM_CHCFGR1_CKOUTSRC(clk_src));
if (ret < 0)
goto pm_put;
/* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTDIV_MASK,
DFSDM_CHCFGR1_CKOUTDIV(clk_div));
if (ret < 0)
goto pm_put;
/* Global enable of DFSDM interface */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_DFSDMEN_MASK,
DFSDM_CHCFGR1_DFSDMEN(1));
if (ret < 0)
goto pm_put;
}
dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
atomic_read(&priv->n_active_ch));
return 0;
pm_put:
pm_runtime_put_sync(dev);
error_ret:
atomic_dec(&priv->n_active_ch);
return ret;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
/**
* stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
*
* Disable interface if n_active_ch is null
* @dfsdm: Handle used to retrieve dfsdm context.
*/
int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
int ret;
if (atomic_dec_and_test(&priv->n_active_ch)) {
/* Global disable of DFSDM interface */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_DFSDMEN_MASK,
DFSDM_CHCFGR1_DFSDMEN(0));
if (ret < 0)
return ret;
/* Stop SPI CLKOUT */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTDIV_MASK,
DFSDM_CHCFGR1_CKOUTDIV(0));
if (ret < 0)
return ret;
pm_runtime_put_sync(&priv->pdev->dev);
}
dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
atomic_read(&priv->n_active_ch));
return 0;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);
static int stm32_dfsdm_parse_of(struct platform_device *pdev,
struct dfsdm_priv *priv)
{
struct device_node *node = pdev->dev.of_node;
struct resource *res;
unsigned long clk_freq, divider;
unsigned int spi_freq, rem;
int ret;
if (!node)
return -EINVAL;
priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
&res);
if (IS_ERR(priv->dfsdm.base))
return PTR_ERR(priv->dfsdm.base);
priv->dfsdm.phys_base = res->start;
/*
* "dfsdm" clock is mandatory for DFSDM peripheral clocking.
* "dfsdm" or "audio" clocks can be used as source clock for
* the SPI clock out signal and internal processing, depending
* on use case.
*/
priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
if (IS_ERR(priv->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
"Failed to get clock\n");
priv->aclk = devm_clk_get(&pdev->dev, "audio");
if (IS_ERR(priv->aclk))
priv->aclk = NULL;
if (priv->aclk)
clk_freq = clk_get_rate(priv->aclk);
else
clk_freq = clk_get_rate(priv->clk);
/* SPI clock out frequency */
ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
&spi_freq);
if (ret < 0) {
/* No SPI master mode */
return 0;
}
divider = div_u64_rem(clk_freq, spi_freq, &rem);
/* Round up divider when ckout isn't precise, not to exceed spi_freq */
if (rem)
divider++;
/* programmable divider is in range of [2:256] */
if (divider < 2 || divider > 256) {
dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
return -EINVAL;
}
/* SPI clock output divider is: divider = CKOUTDIV + 1 */
priv->spi_clk_out_div = divider - 1;
priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);
if (rem) {
dev_warn(&pdev->dev, "SPI clock not accurate\n");
dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
}
return 0;
};
static const struct of_device_id stm32_dfsdm_of_match[] = {
{
.compatible = "st,stm32h7-dfsdm",
.data = &stm32h7_dfsdm_data,
},
{
.compatible = "st,stm32mp1-dfsdm",
.data = &stm32mp1_dfsdm_data,
},
{}
};
MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
static int stm32_dfsdm_probe_identification(struct platform_device *pdev,
struct dfsdm_priv *priv,
const struct stm32_dfsdm_dev_data *dev_data)
{
struct device_node *np = pdev->dev.of_node;
struct device_node *child;
struct stm32_dfsdm *dfsdm = &priv->dfsdm;
const char *compat;
int ret, count = 0;
u32 id, val;
if (!dev_data->ipid) {
dfsdm->num_fls = dev_data->num_filters;
dfsdm->num_chs = dev_data->num_channels;
return 0;
}
ret = regmap_read(dfsdm->regmap, DFSDM_IPIDR, &id);
if (ret)
return ret;
if (id != dev_data->ipid) {
dev_err(&pdev->dev, "Unexpected IP version: 0x%x", id);
return -EINVAL;
}
for_each_child_of_node(np, child) {
ret = of_property_read_string(child, "compatible", &compat);
if (ret)
continue;
/* Count only child nodes with dfsdm compatible */
if (strstr(compat, "dfsdm"))
count++;
}
ret = regmap_read(dfsdm->regmap, DFSDM_HWCFGR, &val);
if (ret)
return ret;
dfsdm->num_fls = FIELD_GET(DFSDM_HWCFGR_NBF_MASK, val);
dfsdm->num_chs = FIELD_GET(DFSDM_HWCFGR_NBT_MASK, val);
if (count > dfsdm->num_fls) {
dev_err(&pdev->dev, "Unexpected child number: %d", count);
return -EINVAL;
}
ret = regmap_read(dfsdm->regmap, DFSDM_VERR, &val);
if (ret)
return ret;
dev_dbg(&pdev->dev, "DFSDM version: %lu.%lu. %d channels/%d filters\n",
FIELD_GET(DFSDM_VERR_MAJREV_MASK, val),
FIELD_GET(DFSDM_VERR_MINREV_MASK, val),
dfsdm->num_chs, dfsdm->num_fls);
return 0;
}
static int stm32_dfsdm_probe(struct platform_device *pdev)
{
struct dfsdm_priv *priv;
const struct stm32_dfsdm_dev_data *dev_data;
struct stm32_dfsdm *dfsdm;
int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->pdev = pdev;
dev_data = of_device_get_match_data(&pdev->dev);
dfsdm = &priv->dfsdm;
ret = stm32_dfsdm_parse_of(pdev, priv);
if (ret < 0)
return ret;
dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
dfsdm->base,
dev_data->regmap_cfg);
if (IS_ERR(dfsdm->regmap)) {
ret = PTR_ERR(dfsdm->regmap);
dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
__func__, ret);
return ret;
}
ret = stm32_dfsdm_probe_identification(pdev, priv, dev_data);
if (ret < 0)
return ret;
dfsdm->fl_list = devm_kcalloc(&pdev->dev, dfsdm->num_fls,
sizeof(*dfsdm->fl_list), GFP_KERNEL);
if (!dfsdm->fl_list)
return -ENOMEM;
dfsdm->ch_list = devm_kcalloc(&pdev->dev, dfsdm->num_chs,
sizeof(*dfsdm->ch_list), GFP_KERNEL);
if (!dfsdm->ch_list)
return -ENOMEM;
platform_set_drvdata(pdev, dfsdm);
ret = stm32_dfsdm_clk_prepare_enable(dfsdm);
if (ret) {
dev_err(&pdev->dev, "Failed to start clock\n");
return ret;
}
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
if (ret)
goto pm_put;
pm_runtime_put(&pdev->dev);
return 0;
pm_put:
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
stm32_dfsdm_clk_disable_unprepare(dfsdm);
return ret;
}
static void stm32_dfsdm_core_remove(struct platform_device *pdev)
{
struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);
pm_runtime_get_sync(&pdev->dev);
of_platform_depopulate(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
stm32_dfsdm_clk_disable_unprepare(dfsdm);
}
static int stm32_dfsdm_core_suspend(struct device *dev)
{
struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
int ret;
ret = pm_runtime_force_suspend(dev);
if (ret)
return ret;
/* Balance devm_regmap_init_mmio_clk() clk_prepare() */
clk_unprepare(priv->clk);
return pinctrl_pm_select_sleep_state(dev);
}
static int stm32_dfsdm_core_resume(struct device *dev)
{
struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
int ret;
ret = pinctrl_pm_select_default_state(dev);
if (ret)
return ret;
ret = clk_prepare(priv->clk);
if (ret)
return ret;
return pm_runtime_force_resume(dev);
}
static int stm32_dfsdm_core_runtime_suspend(struct device *dev)
{
struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
stm32_dfsdm_clk_disable_unprepare(dfsdm);
return 0;
}
static int stm32_dfsdm_core_runtime_resume(struct device *dev)
{
struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
return stm32_dfsdm_clk_prepare_enable(dfsdm);
}
static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {
SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend, stm32_dfsdm_core_resume)
RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,
stm32_dfsdm_core_runtime_resume,
NULL)
};
static struct platform_driver stm32_dfsdm_driver = {
.probe = stm32_dfsdm_probe,
.remove_new = stm32_dfsdm_core_remove,
.driver = {
.name = "stm32-dfsdm",
.of_match_table = stm32_dfsdm_of_match,
.pm = pm_ptr(&stm32_dfsdm_core_pm_ops),
},
};
module_platform_driver(stm32_dfsdm_driver);
MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
MODULE_LICENSE("GPL v2");