On Thu, Jun 01, 2017 at 07:25:33AM -0700, Patrick Venture wrote:
> The aspeed-pwm-tacho controller supports measuring the fan tach by using
> leading, falling, or both edges. This change allows the driver to
> support either of the three configurations and will appropriately modify
> the returned tach data.
>
> If the controller is measuring with both edges it can return a value more
> quickly to the requestor. This version of the driver should still take ~1s
> to return with an RPM value per fan, however, it can be tuned faster with
> double edge counting enabled than without.
>
> I tested this and found the number returned matched what I expected.
>
> Signed-off-by: Patrick Venture <[email protected]>
Applied to hwmon-next.
Thanks,
Guenter
> ---
> drivers/hwmon/aspeed-pwm-tacho.c | 24 +++++++++++++++++++++---
> 1 file changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwmon/aspeed-pwm-tacho.c
> b/drivers/hwmon/aspeed-pwm-tacho.c
> index 48403a2115be..f288928b5e8a 100644
> --- a/drivers/hwmon/aspeed-pwm-tacho.c
> +++ b/drivers/hwmon/aspeed-pwm-tacho.c
> @@ -145,11 +145,20 @@
>
> #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
> +/*
> + * 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 0x1000
> #define INIT_FAN_CTRL 0xFF
>
> @@ -162,6 +171,7 @@ 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];
> @@ -498,7 +508,7 @@ static u32 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;
> + u8 fan_tach_ch_source, type, mode, both;
>
> regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0);
> regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0x1 << fan_tach_ch);
> @@ -512,7 +522,14 @@ static u32 aspeed_get_fan_tach_ch_rpm(struct
> aspeed_pwm_tacho_data *priv,
> regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val);
> 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)
> @@ -696,6 +713,7 @@ 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);
> }
--
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