Re: [PATCH 2/2] leds: add Qualcomm PM8941 WLED driver

From: Bryan Wu
Date: Tue Dec 16 2014 - 19:54:37 EST


On Mon, Dec 8, 2014 at 4:22 PM, Bjorn Andersson
<bjorn.andersson@xxxxxxxxxxxxxx> wrote:
> From: Courtney Cavin <courtney.cavin@xxxxxxxxxxxxxx>
>
> This adds support for the WLED ('White' LED) block on Qualcomm's
> PM8941 PMICs.
>
> Signed-off-by: Courtney Cavin <courtney.cavin@xxxxxxxxxxxxxx>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
> ---
> drivers/leds/Kconfig | 8 +
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-pm8941-wled.c | 466 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 475 insertions(+)
> create mode 100644 drivers/leds/leds-pm8941-wled.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index a210338..9091cf4 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -505,6 +505,14 @@ config LEDS_VERSATILE
> This option enabled support for the LEDs on the ARM Versatile
> and RealView boards. Say Y to enabled these.
>
> +config LEDS_PM8941_WLED
> + tristate "LED support for the Qualcomm PM8941 WLED block"
> + depends on LEDS_CLASS
> + depends on REGMAP
Here should be "select REGMAP"

> + help
> + This option enables support for the 'White' LED block
> + on Qualcomm PM8941 PMICs.
> +
> comment "LED Triggers"
> source "drivers/leds/trigger/Kconfig"
>
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index a2b1647..5474afc 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -56,6 +56,7 @@ obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
> obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
> obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o
> obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
> +obj-$(CONFIG_LEDS_PM8941_WLED) += leds-pm8941-wled.o
>
> # LED SPI Drivers
> obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
> diff --git a/drivers/leds/leds-pm8941-wled.c b/drivers/leds/leds-pm8941-wled.c
> new file mode 100644
> index 0000000..aa06d0b
> --- /dev/null
> +++ b/drivers/leds/leds-pm8941-wled.c
> @@ -0,0 +1,466 @@
> +/* Copyright (c) 2013, Sony Mobile Communications, AB.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +
> +enum pm8941_wled_reg {
> + PM8941_WLED_REG_VAL_BASE = 0x40,
> +#define PM8941_WLED_REG_VAL_MAX 0xFFF
> +
> + PM8941_WLED_REG_MOD_EN = 0x46,
> +#define PM8941_WLED_REG_MOD_EN_BIT BIT(7)
> +#define PM8941_WLED_REG_MOD_EN_MASK BIT(7)
> +
> + PM8941_WLED_REG_SYNC = 0x47,
> +#define PM8941_WLED_REG_SYNC_MASK 0x07
> +#define PM8941_WLED_REG_SYNC_LED1 BIT(0)
> +#define PM8941_WLED_REG_SYNC_LED2 BIT(1)
> +#define PM8941_WLED_REG_SYNC_LED3 BIT(2)
> +#define PM8941_WLED_REG_SYNC_ALL 0x07
> +#define PM8941_WLED_REG_SYNC_CLEAR 0x00
> +
> + PM8941_WLED_REG_FREQ = 0x4c,
> +#define PM8941_WLED_REG_FREQ_MASK 0x0f
> +
> + PM8941_WLED_REG_OVP = 0x4d,
> +#define PM8941_WLED_REG_OVP_MASK 0x03
> +
> + PM8941_WLED_REG_BOOST = 0x4e,
> +#define PM8941_WLED_REG_BOOST_MASK 0x07
> +
> + PM8941_WLED_REG_SINK = 0x4f,
> +#define PM8941_WLED_REG_SINK_MASK 0xe0
> +#define PM8941_WLED_REG_SINK_SHFT 0x05
> +
> +/* Per-'string' registers below */
> +#define PM8941_WLED_REG_STR_OFFSET 0x10
> +
> + PM8941_WLED_REG_STR_MOD_EN_BASE = 0x60,
> +#define PM8941_WLED_REG_STR_MOD_EN BIT(7)
> +#define PM8941_WLED_REG_STR_MOD_MASK BIT(7)
> +
> + PM8941_WLED_REG_STR_SCALE_BASE = 0x62,
> +#define PM8941_WLED_REG_STR_SCALE_MASK 0x1f
> +
> + PM8941_WLED_REG_STR_MOD_SRC_BASE = 0x63,
> +#define PM8941_WLED_REG_STR_MOD_SRC_MASK 0x01
> +#define PM8941_WLED_REG_STR_MOD_SRC_INT 0x00
> +#define PM8941_WLED_REG_STR_MOD_SRC_EXT 0x01
> +
> + PM8941_WLED_REG_STR_CABC_BASE = 0x66,
> +#define PM8941_WLED_REG_STR_CABC_MASK BIT(7)
> +#define PM8941_WLED_REG_STR_CABC_EN BIT(7)
> +};
> +
> +struct pm8941_wled_config {
> + u32 i_boost_limit;
> + u32 ovp;
> + u32 switch_freq;
> + u32 num_strings;
> + u32 i_limit;
> + bool cs_out_en;
> + bool ext_gen;
> + bool cabc_en;
> +};
> +
> +struct pm8941_wled {
> + struct led_classdev cdev;
> + struct pm8941_wled_config cfg;
> + u16 addr;
> +};
> +
> +struct pm8941_wled_context {
> + struct pm8941_wled wled;
> + struct regmap *regmap;
> +};
> +

I think you can just add *regmap into pm8941_wled struct and
pm8941_wled_context is redundant to me.

> +static int pm8941_wled_set(struct led_classdev *cdev,
> + enum led_brightness value)
> +{
> + struct pm8941_wled_context *ctx;
> + struct pm8941_wled *wled;
> + u8 ctrl = 0;
> + u16 val;
> + int rc;
> + int i;
> +
> + wled = container_of(cdev, struct pm8941_wled, cdev);
> + ctx = container_of(wled, struct pm8941_wled_context, wled);
> +
> + if (value != 0)
> + ctrl = PM8941_WLED_REG_MOD_EN_BIT;
> +
> + val = (value * PM8941_WLED_REG_VAL_MAX) / LED_FULL;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_MOD_EN,
> + PM8941_WLED_REG_MOD_EN_MASK, ctrl);
> + if (rc)
> + return rc;
> +
> + for (i = 0; i < wled->cfg.num_strings; ++i) {
> + u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
> +
> + rc = regmap_bulk_write(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i,
> + v, 2);
> + if (rc)
> + return rc;
> + }
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_SYNC,
> + PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL);
> + if (rc)
> + return rc;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_SYNC,
> + PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR);
> + return rc;
> +}
> +
> +static void pm8941_wled_set_brightness(struct led_classdev *cdev,
> + enum led_brightness value)
> +{
> + if (pm8941_wled_set(cdev, value)) {
> + dev_err(cdev->dev, "Unable to set brightness\n");
> + return;
> + }
> + cdev->brightness = value;
> +}
> +
> +static int pm8941_wled_setup(struct pm8941_wled *wled)
> +{
> + struct pm8941_wled_context *ctx;
> + int rc;
> + int i;
> +
> + ctx = container_of(wled, struct pm8941_wled_context, wled);
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_OVP,
> + PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp);
> + if (rc)
> + return rc;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_BOOST,
> + PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit);
> + if (rc)
> + return rc;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_FREQ,
> + PM8941_WLED_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)
> + << PM8941_WLED_REG_SINK_SHFT;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + wled->addr + PM8941_WLED_REG_SINK,
> + PM8941_WLED_REG_SINK_MASK, all);
> + if (rc)
> + return rc;
> + }
> +
> + for (i = 0; i < wled->cfg.num_strings; ++i) {
> + u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + addr + PM8941_WLED_REG_STR_MOD_EN_BASE,
> + PM8941_WLED_REG_STR_MOD_MASK,
> + PM8941_WLED_REG_STR_MOD_EN);
> + if (rc)
> + return rc;
> +
> + if (wled->cfg.ext_gen) {
> + rc = regmap_update_bits(ctx->regmap,
> + addr + PM8941_WLED_REG_STR_MOD_SRC_BASE,
> + PM8941_WLED_REG_STR_MOD_SRC_MASK,
> + PM8941_WLED_REG_STR_MOD_SRC_EXT);
> + if (rc)
> + return rc;
> + }
> +
> + rc = regmap_update_bits(ctx->regmap,
> + addr + PM8941_WLED_REG_STR_SCALE_BASE,
> + PM8941_WLED_REG_STR_SCALE_MASK,
> + wled->cfg.i_limit);
> + if (rc)
> + return rc;
> +
> + rc = regmap_update_bits(ctx->regmap,
> + addr + PM8941_WLED_REG_STR_CABC_BASE,
> + PM8941_WLED_REG_STR_CABC_MASK,
> + wled->cfg.cabc_en ?
> + PM8941_WLED_REG_STR_CABC_EN : 0);
> + if (rc)
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> +static const struct pm8941_wled_config pm8941_wled_config_defaults = {
> + .i_boost_limit = 3,
> + .i_limit = 20,
> + .ovp = 2,
> + .switch_freq = 5,
> + .num_strings = 0,
> + .cs_out_en = false,
> + .ext_gen = false,
> + .cabc_en = false,
> +};
> +
> +struct pm8941_wled_var_cfg {
> + const u32 *values;
> + u32 (*fn)(u32);
> + int size;
> +};
> +
> +static const u32 pm8941_wled_i_boost_limit_values[] = {
> + 105, 385, 525, 805, 980, 1260, 1400, 1680,
> +};
> +
> +static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = {
> + .values = pm8941_wled_i_boost_limit_values,
> + .size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values),
> +};
> +
> +static const u32 pm8941_wled_ovp_values[] = {
> + 35, 32, 29, 27,
> +};
> +
> +static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = {
> + .values = pm8941_wled_ovp_values,
> + .size = ARRAY_SIZE(pm8941_wled_ovp_values),
> +};
> +
> +static u32 pm8941_wled_num_strings_values_fn(u32 idx)
> +{
> + return idx + 1;
> +}
> +
> +static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = {
> + .fn = pm8941_wled_num_strings_values_fn,
> + .size = 3,
> +};
> +
> +static u32 pm8941_wled_switch_freq_values_fn(u32 idx)
> +{
> + return 19200 / (2 * (1 + idx));
> +}
> +
> +static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = {
> + .fn = pm8941_wled_switch_freq_values_fn,
> + .size = 16,
> +};
> +
> +static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = {
> + .size = 26,
> +};
> +
> +static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
> +{
> + if (idx >= cfg->size)
> + return UINT_MAX;
> + if (cfg->fn)
> + return cfg->fn(idx);
> + if (cfg->values)
> + return cfg->values[idx];
> + return idx;
> +}
> +
> +static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
> +{
> + struct pm8941_wled_config *cfg = &wled->cfg;
> + u32 val;
> + int rc;
> + int i;
> +
> + const struct {
> + const char *name;
> + u32 *val_ptr;
> + const struct pm8941_wled_var_cfg *cfg;
> + } u32_opts[] = {
> + {
> + "qcom,current-boost-limit", &cfg->i_boost_limit,
> + .cfg = &pm8941_wled_i_boost_limit_cfg,
> + },
> + {
> + "qcom,current-limit", &cfg->i_limit,
> + .cfg = &pm8941_wled_i_limit_cfg,
> + },
> + {
> + "qcom,ovp", &cfg->ovp,
> + .cfg = &pm8941_wled_ovp_cfg,
> + },
> + {
> + "qcom,switching-freq", &cfg->switch_freq,
> + .cfg = &pm8941_wled_switch_freq_cfg,
> + },
> + {
> + "qcom,num-strings", &cfg->num_strings,
> + .cfg = &pm8941_wled_num_strings_cfg,
> + },
> + };
> + const struct {
> + const char *name;
> + bool *val_ptr;
> + } bool_opts[] = {
> + { "qcom,cs-out", &cfg->cs_out_en, },
> + { "qcom,ext-gen", &cfg->ext_gen, },
> + { "qcom,cabc", &cfg->cabc_en, },
> + };
> +
> + if (dev->of_node == NULL) {
> + dev_err(dev, "no OF node!\n");
> + return -EINVAL;
> + }
> +
> + 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;
> + }
> + wled->addr = val;
> +
> + rc = of_property_read_string(dev->of_node, "label", &wled->cdev.name);
> + if (rc)
> + wled->cdev.name = dev->of_node->name;
> +
> + wled->cdev.default_trigger = of_get_property(dev->of_node,
> + "linux,default-trigger", NULL);
> +
> + *cfg = pm8941_wled_config_defaults;
> + for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
> + u32 sel, c;
> + int j, rj;
> +
> + rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
> + if (rc) {
> + if (rc != -EINVAL) {
> + dev_err(dev, "error reading '%s'\n",
> + u32_opts[i].name);
> + return rc;
> + }
> + continue;
> + }
> +
> + sel = UINT_MAX;
> + rj = -1;
> + c = pm8941_wled_values(u32_opts[i].cfg, 0);
> + for (j = 0; c != UINT_MAX; ++j) {
> + if (c <= val && (sel == UINT_MAX || c >= sel)) {
> + sel = c;
> + rj = j;
> + }
> + c = pm8941_wled_values(u32_opts[i].cfg, j + 1);
> + }
> + if (sel == UINT_MAX) {
> + dev_err(dev, "invalid value for '%s'\n",
> + u32_opts[i].name);
> + return rc;
> + }
> + if (sel != val) {
> + dev_warn(dev, "rounding '%s' down to %u\n",
> + u32_opts[i].name, sel);
> + }
> + dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, sel);
> + *u32_opts[i].val_ptr = rj;
> + };
> +
> + for (i = 0; i < ARRAY_SIZE(bool_opts); ++i) {
> + if (of_property_read_bool(dev->of_node, bool_opts[i].name))
> + *bool_opts[i].val_ptr = true;
> + }
> +
> + cfg->num_strings = cfg->num_strings + 1;
> +
> + return 0;
> +}
> +
> +static int pm8941_wled_probe(struct platform_device *pdev)
> +{
> + struct pm8941_wled_context *ctx;
> + struct regmap *regmap;
> + int rc;
> +
> + regmap = dev_get_regmap(pdev->dev.parent, NULL);
> + if (!regmap) {
> + dev_err(&pdev->dev, "Unable to get regmap\n");
> + return -EINVAL;
> + }
> +

Is this regmap mmio registers or i2c registers? Will the regmap
operation sleep?

> + ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
> + if (ctx == NULL)
> + return -ENOMEM;
> +
> + ctx->regmap = regmap;
> +
> + rc = pm8941_wled_configure(&ctx->wled, &pdev->dev);
> + if (rc)
> + return rc;
> +
> + rc = pm8941_wled_setup(&ctx->wled);
> + if (rc)
> + return rc;
> +
> + ctx->wled.cdev.brightness_set = pm8941_wled_set_brightness;
> +
> + rc = led_classdev_register(&pdev->dev, &ctx->wled.cdev);
> + if (rc)
> + return rc;
> +
> + platform_set_drvdata(pdev, ctx);
> + dev_info(&pdev->dev, "registered led \"%s\"\n", ctx->wled.cdev.name);
> +
> + return 0;
> +};
> +
> +static int pm8941_wled_remove(struct platform_device *pdev)
> +{
> + struct pm8941_wled_context *ctx;
> +
> + ctx = platform_get_drvdata(pdev);
> + led_classdev_unregister(&ctx->wled.cdev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id pm8941_wled_match_table[] = {
> + { .compatible = "qcom,pm8941-wled" },
> + {}
> +};
> +
> +static struct platform_driver pm8941_wled_driver = {
> + .probe = pm8941_wled_probe,
> + .remove = pm8941_wled_remove,
> + .driver = {
> + .name = "pm8941-wled",
> + .owner = THIS_MODULE,
> + .of_match_table = pm8941_wled_match_table,
> + },
> +};
> +
> +module_platform_driver(pm8941_wled_driver);
> +
> +MODULE_DESCRIPTION("pm8941 wled driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform: pm8941-wled");
No space after ":"

> --
> 1.8.2.2
>
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