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

From: kgunda
Date: Thu Oct 17 2019 - 08:27:22 EST


On 2019-10-17 16:36, Daniel Thompson wrote:
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).

I will address it in next series.

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);
--
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