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path: root/drivers/hwmon/aspeed-pwm-tacho.c
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Diffstat (limited to 'drivers/hwmon/aspeed-pwm-tacho.c')
-rw-r--r--drivers/hwmon/aspeed-pwm-tacho.c50
1 files changed, 40 insertions, 10 deletions
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 9de13d626c68..ddfe66bdff86 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -146,14 +146,26 @@
#define PWM_MAX 255
+#define BOTH_EDGES 0x02 /* 10b */
+
#define M_PWM_DIV_H 0x00
#define M_PWM_DIV_L 0x05
#define M_PWM_PERIOD 0x5F
#define M_TACH_CLK_DIV 0x00
-#define M_TACH_MODE 0x00
-#define M_TACH_UNIT 0x1000
+/*
+ * 5:4 Type N fan tach mode selection bit:
+ * 00: falling
+ * 01: rising
+ * 10: both
+ * 11: reserved.
+ */
+#define M_TACH_MODE 0x02 /* 10b */
+#define M_TACH_UNIT 0x00c0
#define INIT_FAN_CTRL 0xFF
+/* How long we sleep in us while waiting for an RPM result. */
+#define ASPEED_RPM_STATUS_SLEEP_USEC 500
+
struct aspeed_pwm_tacho_data {
struct regmap *regmap;
unsigned long clk_freq;
@@ -163,6 +175,7 @@ struct aspeed_pwm_tacho_data {
u8 type_pwm_clock_division_h[3];
u8 type_pwm_clock_division_l[3];
u8 type_fan_tach_clock_division[3];
+ u8 type_fan_tach_mode[3];
u16 type_fan_tach_unit[3];
u8 pwm_port_type[8];
u8 pwm_port_fan_ctrl[8];
@@ -498,8 +511,9 @@ static u32 aspeed_get_fan_tach_ch_measure_period(struct aspeed_pwm_tacho_data
static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
u8 fan_tach_ch)
{
- u32 raw_data, tach_div, clk_source, sec, val;
- u8 fan_tach_ch_source, type;
+ u32 raw_data, tach_div, clk_source, msec, usec, val;
+ u8 fan_tach_ch_source, type, mode, both;
+ int ret;
regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0);
regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0x1 << fan_tach_ch);
@@ -507,16 +521,31 @@ static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
fan_tach_ch_source = priv->fan_tach_ch_source[fan_tach_ch];
type = priv->pwm_port_type[fan_tach_ch_source];
- sec = (1000 / aspeed_get_fan_tach_ch_measure_period(priv, type));
- msleep(sec);
+ msec = (1000 / aspeed_get_fan_tach_ch_measure_period(priv, type));
+ usec = msec * 1000;
+
+ ret = regmap_read_poll_timeout(
+ priv->regmap,
+ ASPEED_PTCR_RESULT,
+ val,
+ (val & RESULT_STATUS_MASK),
+ ASPEED_RPM_STATUS_SLEEP_USEC,
+ usec);
- regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val);
- if (!(val & RESULT_STATUS_MASK))
- return -ETIMEDOUT;
+ /* return -ETIMEDOUT if we didn't get an answer. */
+ if (ret)
+ return ret;
raw_data = val & RESULT_VALUE_MASK;
tach_div = priv->type_fan_tach_clock_division[type];
- tach_div = 0x4 << (tach_div * 2);
+ /*
+ * We need the mode to determine if the raw_data is double (from
+ * counting both edges).
+ */
+ mode = priv->type_fan_tach_mode[type];
+ both = (mode & BOTH_EDGES) ? 1 : 0;
+
+ tach_div = (0x4 << both) << (tach_div * 2);
clk_source = priv->clk_freq;
if (raw_data == 0)
@@ -702,6 +731,7 @@ static void aspeed_create_type(struct aspeed_pwm_tacho_data *priv)
aspeed_set_tacho_type_enable(priv->regmap, TYPEM, true);
priv->type_fan_tach_clock_division[TYPEM] = M_TACH_CLK_DIV;
priv->type_fan_tach_unit[TYPEM] = M_TACH_UNIT;
+ priv->type_fan_tach_mode[TYPEM] = M_TACH_MODE;
aspeed_set_tacho_type_values(priv->regmap, TYPEM, M_TACH_MODE,
M_TACH_UNIT, M_TACH_CLK_DIV);
}