Re: [PATCH V7 4/6] backlight: qcom-wled: Add support for WLED4 peripheral.

From: Daniel Thompson
Date: Thu Oct 17 2019 - 07:06:43 EST

On Wed, Oct 16, 2019 at 03:43:44PM +0530, Kiran Gunda wrote:
> WLED4 peripheral is present on some PMICs like pmi8998 and
> pm660l. It has a different register map and configurations
> are also different. Add support for it.

There is code buried in this patch that looks like it changes the name
that will be handed to the backlight sub-system.

It's purpose needs to be explained in the patch description (or the code
moved to a new patch).


Daniel.

>
> Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
> drivers/video/backlight/qcom-wled.c | 263 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 257 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 45eeda4..2807b4b 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -17,7 +17,7 @@
>
> #define WLED3_SINK_REG_BRIGHT_MAX 0xFFF
>
> -/* WLED3 control registers */
> +/* WLED3/WLED4 control registers */
> #define WLED3_CTRL_REG_MOD_EN 0x46
> #define WLED3_CTRL_REG_MOD_EN_MASK BIT(7)
> #define WLED3_CTRL_REG_MOD_EN_SHIFT 7
> @@ -31,7 +31,7 @@
> #define WLED3_CTRL_REG_ILIMIT 0x4e
> #define WLED3_CTRL_REG_ILIMIT_MASK GENMASK(2, 0)
>
> -/* WLED3 sink registers */
> +/* WLED3/WLED4 sink registers */
> #define WLED3_SINK_REG_SYNC 0x47
> #define WLED3_SINK_REG_SYNC_CLEAR 0x00
>
> @@ -56,6 +56,28 @@
> #define WLED3_SINK_REG_STR_CABC(n) (0x66 + (n * 0x10))
> #define WLED3_SINK_REG_STR_CABC_MASK BIT(7)
>
> +/* WLED4 specific sink registers */
> +#define WLED4_SINK_REG_CURR_SINK 0x46
> +#define WLED4_SINK_REG_CURR_SINK_MASK GENMASK(7, 4)
> +#define WLED4_SINK_REG_CURR_SINK_SHFT 4
> +
> +/* WLED4 specific per-'string' registers below */
> +#define WLED4_SINK_REG_STR_MOD_EN(n) (0x50 + (n * 0x10))
> +#define WLED4_SINK_REG_STR_MOD_MASK BIT(7)
> +
> +#define WLED4_SINK_REG_STR_FULL_SCALE_CURR(n) (0x52 + (n * 0x10))
> +#define WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK GENMASK(3, 0)
> +
> +#define WLED4_SINK_REG_STR_MOD_SRC(n) (0x53 + (n * 0x10))
> +#define WLED4_SINK_REG_STR_MOD_SRC_MASK BIT(0)
> +#define WLED4_SINK_REG_STR_MOD_SRC_INT 0x00
> +#define WLED4_SINK_REG_STR_MOD_SRC_EXT 0x01
> +
> +#define WLED4_SINK_REG_STR_CABC(n) (0x56 + (n * 0x10))
> +#define WLED4_SINK_REG_STR_CABC_MASK BIT(7)
> +
> +#define WLED4_SINK_REG_BRIGHT(n) (0x57 + (n * 0x10))
> +
> struct wled_var_cfg {
> const u32 *values;
> u32 (*fn)(u32);
> @@ -90,6 +112,7 @@ struct wled {
> struct device *dev;
> struct regmap *regmap;
> u16 ctrl_addr;
> + u16 sink_addr;
> u16 max_string_count;
> u32 brightness;
> u32 max_brightness;
> @@ -116,6 +139,29 @@ static int wled3_set_brightness(struct wled *wled, u16 brightness)
> return 0;
> }
>
> +static int wled4_set_brightness(struct wled *wled, u16 brightness)
> +{
> + int rc, i;
> + u16 low_limit = wled->max_brightness * 4 / 1000;
> + u8 v[2];
> +
> + /* WLED4's lower limit of operation is 0.4% */
> + if (brightness > 0 && brightness < low_limit)
> + brightness = low_limit;
> +
> + v[0] = brightness & 0xff;
> + v[1] = (brightness >> 8) & 0xf;
> +
> + for (i = 0; i < wled->cfg.num_strings; ++i) {
> + rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
> + WLED4_SINK_REG_BRIGHT(i), v, 2);
> + if (rc < 0)
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> static int wled_module_enable(struct wled *wled, int val)
> {
> int rc;
> @@ -267,6 +313,120 @@ static int wled3_setup(struct wled *wled)
> .enabled_strings = {0, 1, 2, 3},
> };
>
> +static int wled4_setup(struct wled *wled)
> +{
> + int rc, temp, i, j;
> + u16 addr;
> + u8 sink_en = 0;
> + u32 sink_cfg = 0;
> +
> + rc = regmap_update_bits(wled->regmap,
> + wled->ctrl_addr + WLED3_CTRL_REG_OVP,
> + WLED3_CTRL_REG_OVP_MASK, wled->cfg.ovp);
> + if (rc < 0)
> + return rc;
> +
> + rc = regmap_update_bits(wled->regmap,
> + wled->ctrl_addr + WLED3_CTRL_REG_ILIMIT,
> + WLED3_CTRL_REG_ILIMIT_MASK,
> + wled->cfg.boost_i_limit);
> + if (rc < 0)
> + return rc;
> +
> + rc = regmap_update_bits(wled->regmap,
> + wled->ctrl_addr + WLED3_CTRL_REG_FREQ,
> + WLED3_CTRL_REG_FREQ_MASK,
> + wled->cfg.switch_freq);
> + if (rc < 0)
> + return rc;
> +
> + rc = regmap_read(wled->regmap, wled->sink_addr +
> + WLED4_SINK_REG_CURR_SINK, &sink_cfg);
> + if (rc < 0)
> + return rc;
> +
> + for (i = 0; i < wled->cfg.num_strings; i++) {
> + j = wled->cfg.enabled_strings[i];
> + temp = j + WLED4_SINK_REG_CURR_SINK_SHFT;
> + sink_en |= 1 << temp;
> + }
> +
> + if (sink_cfg == sink_en)
> + return 0;
> +
> + rc = regmap_update_bits(wled->regmap,
> + wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
> + WLED4_SINK_REG_CURR_SINK_MASK, 0);
> + if (rc < 0)
> + return rc;
> +
> + rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> + WLED3_CTRL_REG_MOD_EN,
> + WLED3_CTRL_REG_MOD_EN_MASK, 0);
> + if (rc < 0)
> + return rc;
> +
> + /* Per sink/string configuration */
> + for (i = 0; i < wled->cfg.num_strings; i++) {
> + j = wled->cfg.enabled_strings[i];
> +
> + addr = wled->sink_addr +
> + WLED4_SINK_REG_STR_MOD_EN(j);
> + rc = regmap_update_bits(wled->regmap, addr,
> + WLED4_SINK_REG_STR_MOD_MASK,
> + WLED4_SINK_REG_STR_MOD_MASK);
> + if (rc < 0)
> + return rc;
> +
> + addr = wled->sink_addr +
> + WLED4_SINK_REG_STR_FULL_SCALE_CURR(j);
> + rc = regmap_update_bits(wled->regmap, addr,
> + WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK,
> + wled->cfg.string_i_limit);
> + if (rc < 0)
> + return rc;
> +
> + addr = wled->sink_addr +
> + WLED4_SINK_REG_STR_CABC(j);
> + rc = regmap_update_bits(wled->regmap, addr,
> + WLED4_SINK_REG_STR_CABC_MASK,
> + wled->cfg.cabc ?
> + WLED4_SINK_REG_STR_CABC_MASK : 0);
> + if (rc < 0)
> + return rc;
> + }
> +
> + rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> + WLED3_CTRL_REG_MOD_EN,
> + WLED3_CTRL_REG_MOD_EN_MASK,
> + WLED3_CTRL_REG_MOD_EN_MASK);
> + if (rc < 0)
> + return rc;
> +
> + rc = regmap_update_bits(wled->regmap,
> + wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
> + WLED4_SINK_REG_CURR_SINK_MASK, sink_en);
> + if (rc < 0)
> + return rc;
> +
> + rc = wled_sync_toggle(wled);
> + if (rc < 0) {
> + dev_err(wled->dev, "Failed to toggle sync reg rc:%d\n", rc);
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> +static const struct wled_config wled4_config_defaults = {
> + .boost_i_limit = 4,
> + .string_i_limit = 10,
> + .ovp = 1,
> + .num_strings = 4,
> + .switch_freq = 11,
> + .cabc = false,
> +};
> +
> static const u32 wled3_boost_i_limit_values[] = {
> 105, 385, 525, 805, 980, 1260, 1400, 1680,
> };
> @@ -276,6 +436,15 @@ static int wled3_setup(struct wled *wled)
> .size = ARRAY_SIZE(wled3_boost_i_limit_values),
> };
>
> +static const u32 wled4_boost_i_limit_values[] = {
> + 105, 280, 450, 620, 970, 1150, 1300, 1500,
> +};
> +
> +static const struct wled_var_cfg wled4_boost_i_limit_cfg = {
> + .values = wled4_boost_i_limit_values,
> + .size = ARRAY_SIZE(wled4_boost_i_limit_values),
> +};
> +
> static const u32 wled3_ovp_values[] = {
> 35, 32, 29, 27,
> };
> @@ -285,6 +454,15 @@ static int wled3_setup(struct wled *wled)
> .size = ARRAY_SIZE(wled3_ovp_values),
> };
>
> +static const u32 wled4_ovp_values[] = {
> + 31100, 29600, 19600, 18100,
> +};
> +
> +static const struct wled_var_cfg wled4_ovp_cfg = {
> + .values = wled4_ovp_values,
> + .size = ARRAY_SIZE(wled4_ovp_values),
> +};
> +
> static u32 wled3_num_strings_values_fn(u32 idx)
> {
> return idx + 1;
> @@ -295,6 +473,11 @@ static u32 wled3_num_strings_values_fn(u32 idx)
> .size = 3,
> };
>
> +static const struct wled_var_cfg wled4_num_strings_cfg = {
> + .fn = wled3_num_strings_values_fn,
> + .size = 4,
> +};
> +
> static u32 wled3_switch_freq_values_fn(u32 idx)
> {
> return 19200 / (2 * (1 + idx));
> @@ -309,10 +492,24 @@ static u32 wled3_switch_freq_values_fn(u32 idx)
> .size = 26,
> };
>
> +static const u32 wled4_string_i_limit_values[] = {
> + 0, 2500, 5000, 7500, 10000, 12500, 15000, 17500, 20000,
> + 22500, 25000, 27500, 30000,
> +};
> +
> +static const struct wled_var_cfg wled4_string_i_limit_cfg = {
> + .values = wled4_string_i_limit_values,
> + .size = ARRAY_SIZE(wled4_string_i_limit_values),
> +};
> +
> static const struct wled_var_cfg wled3_string_cfg = {
> .size = 8,
> };
>
> +static const struct wled_var_cfg wled4_string_cfg = {
> + .size = 16,
> +};
> +
> static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
> {
> if (idx >= cfg->size)
> @@ -361,6 +558,34 @@ static int wled_configure(struct wled *wled, int version)
> },
> };
>
> + const struct wled_u32_opts wled4_opts[] = {
> + {
> + .name = "qcom,current-boost-limit",
> + .val_ptr = &cfg->boost_i_limit,
> + .cfg = &wled4_boost_i_limit_cfg,
> + },
> + {
> + .name = "qcom,current-limit-microamp",
> + .val_ptr = &cfg->string_i_limit,
> + .cfg = &wled4_string_i_limit_cfg,
> + },
> + {
> + .name = "qcom,ovp-millivolt",
> + .val_ptr = &cfg->ovp,
> + .cfg = &wled4_ovp_cfg,
> + },
> + {
> + .name = "qcom,switching-freq",
> + .val_ptr = &cfg->switch_freq,
> + .cfg = &wled3_switch_freq_cfg,
> + },
> + {
> + .name = "qcom,num-strings",
> + .val_ptr = &cfg->num_strings,
> + .cfg = &wled4_num_strings_cfg,
> + },
> + };
> +
> const struct wled_bool_opts bool_opts[] = {
> { "qcom,cs-out", &cfg->cs_out_en, },
> { "qcom,ext-gen", &cfg->ext_gen, },
> @@ -374,10 +599,6 @@ static int wled_configure(struct wled *wled, int version)
> }
> wled->ctrl_addr = be32_to_cpu(*prop_addr);
>
> - rc = of_property_read_string(dev->of_node, "label", &wled->name);
> - if (rc)
> - wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
> -
> switch (version) {
> case 3:
> u32_opts = wled3_opts;
> @@ -385,6 +606,22 @@ static int wled_configure(struct wled *wled, int version)
> *cfg = wled3_config_defaults;
> wled->wled_set_brightness = wled3_set_brightness;
> wled->max_string_count = 3;
> + wled->sink_addr = wled->ctrl_addr;
> + break;
> +
> + case 4:
> + u32_opts = wled4_opts;
> + size = ARRAY_SIZE(wled4_opts);
> + *cfg = wled4_config_defaults;
> + wled->wled_set_brightness = wled4_set_brightness;
> + wled->max_string_count = 4;
> +
> + prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
> + if (!prop_addr) {
> + dev_err(wled->dev, "invalid IO resources\n");
> + return -EINVAL;
> + }
> + wled->sink_addr = be32_to_cpu(*prop_addr);
> break;
>
> default:
> @@ -392,6 +629,10 @@ static int wled_configure(struct wled *wled, int version)
> return -EINVAL;
> }
>
> + rc = of_property_read_string(dev->of_node, "label", &wled->name);
> + if (rc)
> + wled->name = dev->of_node->name;
> +
> for (i = 0; i < size; ++i) {
> rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
> if (rc == -EINVAL) {
> @@ -483,6 +724,14 @@ static int wled_probe(struct platform_device *pdev)
> }
> break;
>
> + case 4:
> + rc = wled4_setup(wled);
> + if (rc) {
> + dev_err(&pdev->dev, "wled4_setup failed\n");
> + return rc;
> + }
> + break;
> +
> default:
> dev_err(wled->dev, "Invalid WLED version\n");
> break;
> @@ -503,6 +752,8 @@ static int wled_probe(struct platform_device *pdev)
>
> static const struct of_device_id wled_match_table[] = {
> { .compatible = "qcom,pm8941-wled", .data = (void *)3 },
> + { .compatible = "qcom,pmi8998-wled", .data = (void *)4 },
> + { .compatible = "qcom,pm660l-wled", .data = (void *)4 },
> {}
> };
> MODULE_DEVICE_TABLE(of, wled_match_table);
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>