The ASPEED SoC must deassert a reset in order to use the PWM/tach peripheral. Signed-off-by: Joel Stanley <joel@xxxxxxxxx> --- drivers/hwmon/aspeed-pwm-tacho.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c index 63a95e23ca81..693a3d53cab5 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]; @@ -905,6 +907,13 @@ static int aspeed_create_fan(struct device *dev, return 0; } +static void aspeed_pwm_tacho_remove(void *data) +{ + struct aspeed_pwm_tacho_data *priv = data; + + reset_control_assert(priv->rst); +} + static int aspeed_pwm_tacho_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -931,6 +940,19 @@ 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); + + ret = devm_add_action_or_reset(dev, aspeed_pwm_tacho_remove, priv); + if (ret) + return ret; + regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0); regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0); -- 2.15.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html