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path: root/drivers/iio/adc/stm32-dfsdm-core.c
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Diffstat (limited to 'drivers/iio/adc/stm32-dfsdm-core.c')
-rw-r--r--drivers/iio/adc/stm32-dfsdm-core.c180
1 files changed, 152 insertions, 28 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
index bf089f5d6225..0a4d3746d21c 100644
--- a/drivers/iio/adc/stm32-dfsdm-core.c
+++ b/drivers/iio/adc/stm32-dfsdm-core.c
@@ -12,6 +12,8 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>
@@ -90,6 +92,36 @@ struct dfsdm_priv {
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);
+
+ if (priv->aclk)
+ clk_disable_unprepare(priv->aclk);
+ clk_disable_unprepare(priv->clk);
+}
+
/**
* stm32_dfsdm_start_dfsdm - start global dfsdm interface.
*
@@ -98,24 +130,17 @@ struct dfsdm_priv {
*/
int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
{
- struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, 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 = clk_prepare_enable(priv->clk);
+ ret = pm_runtime_get_sync(dev);
if (ret < 0) {
- dev_err(dev, "Failed to start clock\n");
+ pm_runtime_put_noidle(dev);
goto error_ret;
}
- if (priv->aclk) {
- ret = clk_prepare_enable(priv->aclk);
- if (ret < 0) {
- dev_err(dev, "Failed to start audio clock\n");
- goto disable_clk;
- }
- }
/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
clk_src = priv->aclk ? 1 : 0;
@@ -123,21 +148,21 @@ int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
DFSDM_CHCFGR1_CKOUTSRC_MASK,
DFSDM_CHCFGR1_CKOUTSRC(clk_src));
if (ret < 0)
- goto disable_aclk;
+ 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 disable_aclk;
+ 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 disable_aclk;
+ goto pm_put;
}
dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
@@ -145,11 +170,8 @@ int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
return 0;
-disable_aclk:
- clk_disable_unprepare(priv->aclk);
-disable_clk:
- clk_disable_unprepare(priv->clk);
-
+pm_put:
+ pm_runtime_put_sync(dev);
error_ret:
atomic_dec(&priv->n_active_ch);
@@ -165,7 +187,7 @@ EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
*/
int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
{
- struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);
+ struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
int ret;
if (atomic_dec_and_test(&priv->n_active_ch)) {
@@ -183,9 +205,7 @@ int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
if (ret < 0)
return ret;
- clk_disable_unprepare(priv->clk);
- if (priv->aclk)
- clk_disable_unprepare(priv->aclk);
+ 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));
@@ -199,7 +219,7 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
{
struct device_node *node = pdev->dev.of_node;
struct resource *res;
- unsigned long clk_freq;
+ unsigned long clk_freq, divider;
unsigned int spi_freq, rem;
int ret;
@@ -243,13 +263,20 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
return 0;
}
- priv->spi_clk_out_div = div_u64_rem(clk_freq, spi_freq, &rem) - 1;
- if (!priv->spi_clk_out_div) {
- /* spi_clk_out_div == 0 means ckout is OFF */
+ 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;
}
- priv->dfsdm.spi_master_freq = spi_freq;
+
+ /* 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");
@@ -318,14 +345,111 @@ static int stm32_dfsdm_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, dfsdm);
- return devm_of_platform_populate(&pdev->dev);
+ 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 int 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);
+
+ return 0;
+}
+
+static int __maybe_unused 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 __maybe_unused 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 __maybe_unused 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 __maybe_unused 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 = {
+ SET_SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend,
+ stm32_dfsdm_core_resume)
+ SET_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 = stm32_dfsdm_core_remove,
.driver = {
.name = "stm32-dfsdm",
.of_match_table = stm32_dfsdm_of_match,
+ .pm = &stm32_dfsdm_core_pm_ops,
},
};