[PATCH V4 5/8] backlight: qcom-wled: Restructure the driver for WLED3

Kiran Gunda
2018-07-09T10:22:18Z

Restructure the driver to add the support for new WLED
peripherals.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
Changes from V3:
- This is the new patch after splitting the
"backlight: qcom-wled: Add support for WLED4 peripheral" patch
to seperate the WLED3 specific restructure.

drivers/video/backlight/qcom-wled.c | 396 ++++++++++++++++++++++--------------
1 file changed, 246 insertions(+), 150 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 3cd6e75..87fc1d0 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -15,59 +15,71 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_address.h>
#include <linux/regmap.h>

/* From DT binding */
+#define WLED_MAX_STRINGS 4
+
#define WLED_DEFAULT_BRIGHTNESS 2048

-#define WLED3_SINK_REG_BRIGHT_MAX 0xFFF
-#define WLED3_CTRL_REG_VAL_BASE 0x40
+#define WLED_SINK_REG_BRIGHT_MAX 0xFFF

-/* WLED3 control registers */
-#define WLED3_CTRL_REG_MOD_EN 0x46
-#define WLED3_CTRL_REG_MOD_EN_BIT BIT(7)
-#define WLED3_CTRL_REG_MOD_EN_MASK BIT(7)
+/* WLED control registers */
+#define WLED_CTRL_REG_MOD_EN 0x46
+#define WLED_CTRL_REG_MOD_EN_MASK BIT(7)
+#define WLED_CTRL_REG_MOD_EN_SHIFT 7

-#define WLED3_CTRL_REG_FREQ 0x4c
-#define WLED3_CTRL_REG_FREQ_MASK 0x0f
+#define WLED_CTRL_REG_FREQ 0x4c
+#define WLED_CTRL_REG_FREQ_MASK GENMASK(3, 0)

-#define WLED3_CTRL_REG_OVP 0x4d
-#define WLED3_CTRL_REG_OVP_MASK 0x03
+#define WLED_CTRL_REG_OVP 0x4d
+#define WLED_CTRL_REG_OVP_MASK GENMASK(1, 0)

-#define WLED3_CTRL_REG_ILIMIT 0x4e
-#define WLED3_CTRL_REG_ILIMIT_MASK 0x07
+#define WLED_CTRL_REG_ILIMIT 0x4e
+#define WLED_CTRL_REG_ILIMIT_MASK GENMASK(2, 0)

-/* WLED3 sink registers */
-#define WLED3_SINK_REG_SYNC 0x47
-#define WLED3_SINK_REG_SYNC_MASK 0x07
-#define WLED3_SINK_REG_SYNC_LED1 BIT(0)
-#define WLED3_SINK_REG_SYNC_LED2 BIT(1)
-#define WLED3_SINK_REG_SYNC_LED3 BIT(2)
-#define WLED3_SINK_REG_SYNC_ALL 0x07
-#define WLED3_SINK_REG_SYNC_CLEAR 0x00
+/* WLED sink registers */
+#define WLED_SINK_REG_SYNC 0x47
+#define WLED_SINK_REG_SYNC_CLEAR 0x00

#define WLED3_SINK_REG_CURR_SINK 0x4f
-#define WLED3_SINK_REG_CURR_SINK_MASK 0xe0
-#define WLED3_SINK_REG_CURR_SINK_SHFT 0x05
+#define WLED3_SINK_REG_CURR_SINK_MASK GENMASK(7, 5)
+#define WLED3_SINK_REG_CURR_SINK_SHFT 5

-/* WLED3 per-'string' registers below */
-#define WLED3_SINK_REG_STR_OFFSET 0x10
+/* WLED3 specific per-'string' registers below */
+#define WLED3_SINK_REG_BRIGHT(n) (0x40 + n)

-#define WLED3_SINK_REG_STR_MOD_EN_BASE 0x60
+#define WLED3_SINK_REG_STR_MOD_EN(n) (0x60 + (n * 0x10))
#define WLED3_SINK_REG_STR_MOD_MASK BIT(7)
-#define WLED3_SINK_REG_STR_MOD_EN BIT(7)

-#define WLED3_SINK_REG_STR_FULL_SCALE_CURR 0x62
-#define WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK 0x1f
+#define WLED3_SINK_REG_STR_FULL_SCALE_CURR(n) (0x62 + (n * 0x10))
+#define WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK GENMASK(4, 0)

-#define WLED3_SINK_REG_STR_MOD_SRC_BASE 0x63
-#define WLED3_SINK_REG_STR_MOD_SRC_MASK 0x01
+#define WLED3_SINK_REG_STR_MOD_SRC(n) (0x63 + (n * 0x10))
+#define WLED3_SINK_REG_STR_MOD_SRC_MASK BIT(0)
#define WLED3_SINK_REG_STR_MOD_SRC_INT 0x00
#define WLED3_SINK_REG_STR_MOD_SRC_EXT 0x01

-#define WLED3_SINK_REG_STR_CABC_BASE 0x66
+#define WLED3_SINK_REG_STR_CABC(n) (0x66 + (n * 0x10))
#define WLED3_SINK_REG_STR_CABC_MASK BIT(7)
-#define WLED3_SINK_REG_STR_CABC_EN BIT(7)
+
+struct wled_var_cfg {
+ const u32 *values;
+ u32 (*fn)(u32);
+ int size;
+};
+
+struct wled_u32_opts {
+ const char *name;
+ u32 *val_ptr;
+ const struct wled_var_cfg *cfg;
+};
+
+struct wled_bool_opts {
+ const char *name;
+ bool *val_ptr;
+};

struct wled_config {
u32 boost_i_limit;
@@ -75,132 +87,179 @@ struct wled_config {
u32 switch_freq;
u32 num_strings;
u32 string_i_limit;
+ u32 enabled_strings[WLED_MAX_STRINGS];
bool cs_out_en;
bool ext_gen;
- bool cabc_en;
+ bool cabc;
};

struct wled {
const char *name;
+ struct device *dev;
struct regmap *regmap;
- u16 addr;
+ u16 ctrl_addr;
+ u16 max_string_count;
+ u32 brightness;
+ u32 max_brightness;

struct wled_config cfg;
+ int (*wled_set_brightness)(struct wled *wled, u16 brightness);
};

+static int wled3_set_brightness(struct wled *wled, u16 brightness)
+{
+ int rc, i;
+ u8 v[2];
+
+ 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->ctrl_addr +
+ WLED3_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;
+
+ rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
+ WLED_CTRL_REG_MOD_EN,
+ WLED_CTRL_REG_MOD_EN_MASK,
+ val << WLED_CTRL_REG_MOD_EN_SHIFT);
+ return rc;
+}
+
+static int wled_sync_toggle(struct wled *wled)
+{
+ int rc;
+ unsigned int mask = GENMASK(wled->max_string_count - 1, 0);
+
+ rc = regmap_update_bits(wled->regmap,
+ wled->ctrl_addr + WLED_SINK_REG_SYNC,
+ mask, mask);
+ if (rc < 0)
+ return rc;
+
+ rc = regmap_update_bits(wled->regmap,
+ wled->ctrl_addr + WLED_SINK_REG_SYNC,
+ mask, WLED_SINK_REG_SYNC_CLEAR);
+
+ return rc;
+}
+
static int wled_update_status(struct backlight_device *bl)
{
struct wled *wled = bl_get_data(bl);
- u16 val = bl->props.brightness;
- u8 ctrl = 0;
- int rc;
- int i;
+ u16 brightness = bl->props.brightness;
+ int rc = 0;

if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.fb_blank != FB_BLANK_UNBLANK ||
bl->props.state & BL_CORE_FBBLANK)
- val = 0;
-
- if (val != 0)
- ctrl = WLED3_CTRL_REG_MOD_EN_BIT;
+ brightness = 0;

- rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_CTRL_REG_MOD_EN,
- WLED3_CTRL_REG_MOD_EN_MASK, ctrl);
- if (rc)
- return rc;
+ if (brightness) {
+ rc = wled->wled_set_brightness(wled, brightness);
+ if (rc < 0) {
+ dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
+ rc);
+ return rc;
+ }

- for (i = 0; i < wled->cfg.num_strings; ++i) {
- u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
+ rc = wled_sync_toggle(wled);
+ if (rc < 0) {
+ dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
+ return rc;
+ }
+ }

- rc = regmap_bulk_write(wled->regmap,
- wled->addr + WLED3_CTRL_REG_VAL_BASE + 2 * i,
- v, 2);
- if (rc)
+ if (!!brightness != !!wled->brightness) {
+ rc = wled_module_enable(wled, !!brightness);
+ if (rc < 0) {
+ dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
return rc;
+ }
}

- rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_SINK_REG_SYNC,
- WLED3_SINK_REG_SYNC_MASK, WLED3_SINK_REG_SYNC_ALL);
- if (rc)
- return rc;
+ wled->brightness = brightness;

- rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_SINK_REG_SYNC,
- WLED3_SINK_REG_SYNC_MASK, WLED3_SINK_REG_SYNC_CLEAR);
return rc;
}

-static int wled_setup(struct wled *wled)
+static int wled3_setup(struct wled *wled)
{
- int rc;
- int i;
+ u16 addr;
+ u8 sink_en = 0;
+ int rc, i, j;

rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_CTRL_REG_OVP,
- WLED3_CTRL_REG_OVP_MASK, wled->cfg.ovp);
+ wled->ctrl_addr + WLED_CTRL_REG_OVP,
+ WLED_CTRL_REG_OVP_MASK, wled->cfg.ovp);
if (rc)
return rc;

rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_CTRL_REG_ILIMIT,
- WLED3_CTRL_REG_ILIMIT_MASK, wled->cfg.boost_i_limit);
+ wled->ctrl_addr + WLED_CTRL_REG_ILIMIT,
+ WLED_CTRL_REG_ILIMIT_MASK,
+ wled->cfg.boost_i_limit);
if (rc)
return rc;

rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_CTRL_REG_FREQ,
- WLED3_CTRL_REG_FREQ_MASK, wled->cfg.switch_freq);
+ wled->ctrl_addr + WLED_CTRL_REG_FREQ,
+ WLED_CTRL_REG_FREQ_MASK,
+ wled->cfg.switch_freq);
if (rc)
return rc;

- if (wled->cfg.cs_out_en) {
- u8 all = (BIT(wled->cfg.num_strings) - 1)
- << WLED3_SINK_REG_CURR_SINK_SHFT;
-
- rc = regmap_update_bits(wled->regmap,
- wled->addr + WLED3_SINK_REG_CURR_SINK,
- WLED3_SINK_REG_CURR_SINK_MASK, all);
- if (rc)
- return rc;
- }
-
for (i = 0; i < wled->cfg.num_strings; ++i) {
- u16 addr = wled->addr + WLED3_SINK_REG_STR_OFFSET * i;
-
- rc = regmap_update_bits(wled->regmap,
- addr + WLED3_SINK_REG_STR_MOD_EN_BASE,
- WLED3_SINK_REG_STR_MOD_MASK,
- WLED3_SINK_REG_STR_MOD_EN);
+ j = wled->cfg.enabled_strings[i];
+ addr = wled->ctrl_addr + WLED3_SINK_REG_STR_MOD_EN(j);
+ rc = regmap_update_bits(wled->regmap, addr,
+ WLED3_SINK_REG_STR_MOD_MASK,
+ WLED3_SINK_REG_STR_MOD_MASK);
if (rc)
return rc;

if (wled->cfg.ext_gen) {
- rc = regmap_update_bits(wled->regmap,
- addr + WLED3_SINK_REG_STR_MOD_SRC_BASE,
- WLED3_SINK_REG_STR_MOD_SRC_MASK,
- WLED3_SINK_REG_STR_MOD_SRC_EXT);
+ addr = wled->ctrl_addr + WLED3_SINK_REG_STR_MOD_SRC(j);
+ rc = regmap_update_bits(wled->regmap, addr,
+ WLED3_SINK_REG_STR_MOD_SRC_MASK,
+ WLED3_SINK_REG_STR_MOD_SRC_EXT);
if (rc)
return rc;
}

- rc = regmap_update_bits(wled->regmap,
- addr + WLED3_SINK_REG_STR_FULL_SCALE_CURR,
- WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK,
- wled->cfg.string_i_limit);
+ addr = wled->ctrl_addr + WLED3_SINK_REG_STR_FULL_SCALE_CURR(j);
+ rc = regmap_update_bits(wled->regmap, addr,
+ WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK,
+ wled->cfg.string_i_limit);
if (rc)
return rc;

- rc = regmap_update_bits(wled->regmap,
- addr + WLED3_SINK_REG_STR_CABC_BASE,
- WLED3_SINK_REG_STR_CABC_MASK,
- wled->cfg.cabc_en ?
- WLED3_SINK_REG_STR_CABC_EN : 0);
+ addr = wled->ctrl_addr + WLED3_SINK_REG_STR_CABC(j);
+ rc = regmap_update_bits(wled->regmap, addr,
+ WLED3_SINK_REG_STR_CABC_MASK,
+ wled->cfg.cabc ?
+ WLED3_SINK_REG_STR_CABC_MASK : 0);
if (rc)
return rc;
+
+ sink_en |= BIT(j + WLED3_SINK_REG_CURR_SINK_SHFT);
}

+ rc = regmap_update_bits(wled->regmap,
+ wled->ctrl_addr + WLED3_SINK_REG_CURR_SINK,
+ WLED3_SINK_REG_CURR_SINK_MASK, sink_en);
+ if (rc)
+ return rc;
+
return 0;
}

@@ -208,17 +267,11 @@ static int wled_setup(struct wled *wled)
.boost_i_limit = 3,
.string_i_limit = 20,
.ovp = 2,
+ .num_strings = 3,
.switch_freq = 5,
- .num_strings = 0,
.cs_out_en = false,
.ext_gen = false,
- .cabc_en = false,
-};
-
-struct wled_var_cfg {
- const u32 *values;
- u32 (*fn)(u32);
- int size;
+ .cabc = false,
};

static const u32 wled3_boost_i_limit_values[] = {
@@ -263,7 +316,11 @@ static u32 wled3_switch_freq_values_fn(u32 idx)
.size = 26,
};

-static u32 wled3_values(const struct wled_var_cfg *cfg, u32 idx)
+static const struct wled_var_cfg wled3_string_cfg = {
+ .size = 8,
+};
+
+static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
{
if (idx >= cfg->size)
return UINT_MAX;
@@ -274,68 +331,77 @@ static u32 wled3_values(const struct wled_var_cfg *cfg, u32 idx)
return idx;
}

-static int wled_configure(struct wled *wled, struct device *dev)
+#define WLED3 3
+
+static int wled_configure(struct wled *wled, int version)
{
struct wled_config *cfg = &wled->cfg;
- u32 val;
- int rc;
- u32 c;
- int i;
- int j;
-
- const struct {
- const char *name;
- u32 *val_ptr;
- const struct wled_var_cfg *cfg;
- } u32_opts[] = {
+ struct device *dev = wled->dev;
+ const __be32 *prop_addr;
+ u32 size, val, c, string_len;
+ int rc, i, j;
+
+ const struct wled_u32_opts *u32_opts = NULL;
+ const struct wled_u32_opts wled3_opts[] = {
{
- "qcom,current-boost-limit",
- &cfg->boost_i_limit,
+ .name = "qcom,current-boost-limit",
+ .val_ptr = &cfg->boost_i_limit,
.cfg = &wled3_boost_i_limit_cfg,
},
{
- "qcom,current-limit",
- &cfg->string_i_limit,
+ .name = "qcom,current-limit",
+ .val_ptr = &cfg->string_i_limit,
.cfg = &wled3_string_i_limit_cfg,
},
{
- "qcom,ovp",
- &cfg->ovp,
+ .name = "qcom,ovp",
+ .val_ptr = &cfg->ovp,
.cfg = &wled3_ovp_cfg,
},
{
- "qcom,switching-freq",
- &cfg->switch_freq,
+ .name = "qcom,switching-freq",
+ .val_ptr = &cfg->switch_freq,
.cfg = &wled3_switch_freq_cfg,
},
{
- "qcom,num-strings",
- &cfg->num_strings,
+ .name = "qcom,num-strings",
+ .val_ptr = &cfg->num_strings,
.cfg = &wled3_num_strings_cfg,
},
};
- const struct {
- const char *name;
- bool *val_ptr;
- } bool_opts[] = {
+
+ const struct wled_bool_opts bool_opts[] = {
{ "qcom,cs-out", &cfg->cs_out_en, },
{ "qcom,ext-gen", &cfg->ext_gen, },
- { "qcom,cabc", &cfg->cabc_en, },
+ { "qcom,cabc", &cfg->cabc, },
};

- rc = of_property_read_u32(dev->of_node, "reg", &val);
- if (rc || val > 0xffff) {
- dev_err(dev, "invalid IO resources\n");
- return rc ? rc : -EINVAL;
+ prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
+ if (!prop_addr) {
+ dev_err(wled->dev, "invalid IO resources\n");
+ return -EINVAL;
}
- wled->addr = val;
+ wled->ctrl_addr = be32_to_cpu(*prop_addr);

rc = of_property_read_string(dev->of_node, "label", &wled->name);
if (rc)
wled->name = dev->of_node->name;

- *cfg = wled3_config_defaults;
- for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
+ switch (version) {
+ case WLED3:
+ u32_opts = wled3_opts;
+ size = ARRAY_SIZE(wled3_opts);
+ *cfg = wled3_config_defaults;
+ wled->wled_set_brightness = wled3_set_brightness;
+ wled->max_string_count = 3;
+ break;
+
+ default:
+ dev_err(wled->dev, "Invalid WLED version\n");
+ break;
+ }
+
+ for (i = 0; i < size; ++i) {
rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
if (rc == -EINVAL) {
continue;
@@ -346,12 +412,15 @@ static int wled_configure(struct wled *wled, struct device *dev)

c = UINT_MAX;
for (j = 0; c != val; j++) {
- c = wled3_values(u32_opts[i].cfg, j);
+ c = wled_values(u32_opts[i].cfg, j);
if (c == UINT_MAX) {
dev_err(dev, "invalid value for '%s'\n",
u32_opts[i].name);
return -EINVAL;
}
+
+ if (c == val)
+ break;
}

dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c);
@@ -365,6 +434,15 @@ static int wled_configure(struct wled *wled, struct device *dev)

cfg->num_strings = cfg->num_strings + 1;

+ string_len = of_property_count_elems_of_size(dev->of_node,
+ "qcom,enabled-strings",
+ sizeof(u32));
+ if (string_len > 0)
+ rc = of_property_read_u32_array(dev->of_node,
+ "qcom,enabled-strings",
+ wled->cfg.enabled_strings,
+ sizeof(u32));
+
return 0;
}

@@ -378,6 +456,7 @@ static int wled_probe(struct platform_device *pdev)
struct backlight_device *bl;
struct wled *wled;
struct regmap *regmap;
+ int version;
u32 val;
int rc;

@@ -392,22 +471,39 @@ static int wled_probe(struct platform_device *pdev)
return -ENOMEM;

wled->regmap = regmap;
+ wled->dev = &pdev->dev;

- rc = wled_configure(wled, &pdev->dev);
- if (rc)
- return rc;
+ version = (uintptr_t)of_device_get_match_data(&pdev->dev);
+ if (!version) {
+ dev_err(&pdev->dev, "Unknown device version\n");
+ return -ENODEV;
+ }

- rc = wled_setup(wled);
+ rc = wled_configure(wled, version);
if (rc)
return rc;

+ switch (version) {
+ case WLED3:
+ rc = wled3_setup(wled);
+ if (rc) {
+ dev_err(&pdev->dev, "wled3_setup failed\n");
+ return rc;
+ }
+ break;
+
+ default:
+ dev_err(wled->dev, "Invalid WLED version\n");
+ break;
+ }
+
val = WLED_DEFAULT_BRIGHTNESS;
of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);

memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.brightness = val;
- props.max_brightness = WLED3_SINK_REG_BRIGHT_MAX;
+ props.max_brightness = WLED_SINK_REG_BRIGHT_MAX;
bl = devm_backlight_device_register(&pdev->dev, wled->name,
&pdev->dev, wled,
&wled_ops, &props);
@@ -415,7 +511,7 @@ static int wled_probe(struct platform_device *pdev)
};

static const struct of_device_id wled_match_table[] = {
- { .compatible = "qcom,pm8941-wled" },
+ { .compatible = "qcom,pm8941-wled", .data = (void *)3 },
{}
};
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