On Tue, Apr 07, 2020 at 09:17:10PM +0530, Kiran Gunda wrote:
> From: Subbaraman Narayanamurthy <subbaram@xxxxxxxxxxxxxx>
>
> PM8150L WLED supports the following:
> - Two modulators and each sink can use any of the modulator
> - Multiple CABC selection options from which one can be selected/enabled
> - Multiple brightness width selection (12 bits to 15 bits)
>
> Signed-off-by: Subbaraman Narayanamurthy <subbaram@xxxxxxxxxxxxxx>
> Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
> ---
> drivers/video/backlight/qcom-wled.c | 443 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 442 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index a6ddaa9..3a57011 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> ...
> +static const u8 wled5_brightness_reg[MOD_MAX] = {
> + [MOD_A] = WLED5_SINK_REG_MOD_A_BRIGHTNESS_LSB,
> + [MOD_B] = WLED5_SINK_REG_MOD_B_BRIGHTNESS_LSB,
> +};
> +
> +static const u8 wled5_src_sel_reg[MOD_MAX] = {
> + [MOD_A] = WLED5_SINK_REG_MOD_A_SRC_SEL,
> + [MOD_B] = WLED5_SINK_REG_MOD_B_SRC_SEL,
> +};
> +
> +static const u8 wled5_brt_wid_sel_reg[MOD_MAX] = {
> + [MOD_A] = WLED5_SINK_REG_MOD_A_BRIGHTNESS_WIDTH_SEL,
> + [MOD_B] = WLED5_SINK_REG_MOD_B_BRIGHTNESS_WIDTH_SEL,
> +};
> +
Each of these lookup tables are used exactly once... and half the time
when this code chooses between MOD_A and MOD_B a ternary is used and
half the time these lookup tables.
I suggest these be removed.
> static int wled3_set_brightness(struct wled *wled, u16 brightness)
> {
> int rc, i;
> @@ -225,6 +291,25 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
> return 0;
> }
>
> +static int wled5_set_brightness(struct wled *wled, u16 brightness)
> +{
> + int rc, offset;
> + u16 low_limit = wled->max_brightness * 1 / 1000;
Multiplying by 1 is redundant.
> + u8 v[2];
> +
> + /* WLED5's lower limit is 0.1% */
> + if (brightness < low_limit)
> + brightness = low_limit;
> +
> + v[0] = brightness & 0xff;
> + v[1] = (brightness >> 8) & 0x7f;
> +
> + offset = wled5_brightness_reg[wled->cfg.mod_sel];
> + rc = regmap_bulk_write(wled->regmap, wled->sink_addr + offset,
> + v, 2);
> + return rc;
> +}
> +
> static void wled_ovp_work(struct work_struct *work)
> {
> struct wled *wled = container_of(work,
> @@ -317,11 +420,67 @@ static int wled4_ovp_fault_status(struct wled *wled, bool *fault_set)
> return rc;
> }
>
> +static int wled5_ovp_fault_status(struct wled *wled, bool *fault_set)
> +{
> + int rc;
> + u32 int_rt_sts, fault_sts;
> +
> + *fault_set = false;
> + rc = regmap_read(wled->regmap,
> + wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS,
> + &int_rt_sts);
> + if (rc < 0) {
> + dev_err(wled->dev, "Failed to read INT_RT_STS rc=%d\n", rc);
> + return rc;
> + }
> +
> + rc = regmap_read(wled->regmap,
> + wled->ctrl_addr + WLED3_CTRL_REG_FAULT_STATUS,
> + &fault_sts);
> + if (rc < 0) {
> + dev_err(wled->dev, "Failed to read FAULT_STATUS rc=%d\n", rc);
> + return rc;
> + }
> +
> + if (int_rt_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS)
> + *fault_set = true;
> +
> + if (fault_sts & (WLED3_CTRL_REG_OVP_FAULT_BIT |
> + WLED5_CTRL_REG_OVP_PRE_ALARM_BIT))
Correct me if I'm wrong but isn't the only difference between the WLED4
and WLED5 code that the wled5 code also checks the
WLED5_CTRL_REG_OVP_PRE_ALARM_BIT ?
If so why do we need to pull out (and duplicate) this code code using
the function pointers?
> + *fault_set = true;
> +
> + if (*fault_set)
> + dev_dbg(wled->dev, "WLED OVP fault detected, int_rt_sts=0x%x fault_sts=0x%x\n",
> + int_rt_sts, fault_sts);
> +
> + return rc;
> +}
> +
> @@ -615,6 +797,7 @@ static void wled_auto_string_detection(struct wled *wled)
>
> #define WLED_AUTO_DETECT_OVP_COUNT 5
> #define WLED_AUTO_DETECT_CNT_DLY_US USEC_PER_SEC
> +
Nit picking but this additional line is in the wrong patch ;-)
> static bool wled4_auto_detection_required(struct wled *wled)
> {
> s64 elapsed_time_us;
> @@ -648,6 +831,46 @@ static bool wled4_auto_detection_required(struct wled *wled)
> return false;
> }
>
> +static bool wled5_auto_detection_required(struct wled *wled)
> +{
> + s64 elapsed_time_us;
> +
> + if (!wled->cfg.auto_detection_enabled)
> + return false;
> +
> + /*
> + * Check if the OVP fault was an occasional one
> + * or if it's firing continuously, the latter qualifies
> + * for an auto-detection check.
> + */
> + if (!wled->auto_detection_ovp_count) {
> + wled->start_ovp_fault_time = ktime_get();
> + wled->auto_detection_ovp_count++;
> + } else {
> + /*
> + * WLED5 has OVP fault density interrupt configuration i.e. to
> + * count the number of OVP alarms for a certain duration before
> + * triggering OVP fault interrupt. By default, number of OVP
> + * fault events counted before an interrupt is fired is 32 and
> + * the time interval is 12 ms. If we see more than one OVP fault
> + * interrupt, then that should qualify for a real OVP fault
> + * condition to run auto calibration algorithm.
> + */
Given the above why do we have a software mechanism to wait until the
second time the interrupt fires? I'm a bit rusty on this driver but
wasn't there already some mechanism to slightly delay turning on the
fault detection?
Daniel.
