The ASPEED SoC must deassert a reset in order to use the PWM/tach
peripheral.
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
v2:
- Correct horrible mistakes
- Boot tested and hwmon sysfs files checked
---
drivers/hwmon/aspeed-pwm-tacho.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 63a95e23ca81..77bb7a4bbed4 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -19,6 +19,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/reset.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
@@ -181,6 +182,7 @@ struct aspeed_cooling_device {
struct aspeed_pwm_tacho_data {
struct regmap *regmap;
+ struct reset_control *rst;
unsigned long clk_freq;
bool pwm_present[8];
bool fan_tach_present[16];
@@ -931,6 +933,15 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
&aspeed_pwm_tacho_regmap_config);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
+
+ priv->rst = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(priv->rst)) {
+ dev_err(dev,
+ "missing or invalid reset controller device tree entry");
+ return PTR_ERR(priv->rst);
+ }
+ reset_control_deassert(priv->rst);
+
regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0);
regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0);
@@ -960,6 +971,15 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
return PTR_ERR_OR_ZERO(hwmon);
}
+static int aspeed_pwm_tacho_remove(struct platform_device *pdev)
+{
+ struct aspeed_pwm_tacho_data *priv = platform_get_drvdata(pdev);
+
+ reset_control_assert(priv->rst);
+
+ return 0;
+}
+
static const struct of_device_id of_pwm_tacho_match_table[] = {
{ .compatible = "aspeed,ast2400-pwm-tacho", },
{ .compatible = "aspeed,ast2500-pwm-tacho", },
@@ -969,6 +989,7 @@ MODULE_DEVICE_TABLE(of, of_pwm_tacho_match_table);
static struct platform_driver aspeed_pwm_tacho_driver = {
.probe = aspeed_pwm_tacho_probe,
+ .remove = aspeed_pwm_tacho_remove,
.driver = {
.name = "aspeed_pwm_tacho",
.of_match_table = of_pwm_tacho_match_table,
--
2.14.1
--
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