^^^ Also not copied to LKML... On Sun, Mar 10, 2024 at 02:52:57PM +0100, Patrick Gansterer wrote: > This is a general driver for LM3509 backlight chip of TI. > LM3509 is High Efficiency Boost for White LEDs and/or OLED Displays with > Dual Current Sinks. This driver supports OLED/White LED select, brightness > control and sub/main control. > The datasheet can be found at http://www.ti.com/product/lm3509. > > Signed-off-by: Patrick Gansterer <paroga@xxxxxxxxxx> Overall looks good but there are some review comments inline below. > diff --git a/drivers/video/backlight/lm3509_bl.c b/drivers/video/backlight/lm3509_bl.c > new file mode 100644 > index 000000000000..696ec8aab6aa > --- /dev/null > +++ b/drivers/video/backlight/lm3509_bl.c > @@ -0,0 +1,338 @@ > <snip> > +struct lm3509_bl { > + struct regmap *regmap; > + struct backlight_device *bl_main; > + struct backlight_device *bl_sub; > + struct gpio_desc *reset_gpio; > +}; > + > +struct lm3509_bl_led_pdata { What does the p stand for here? (only asking because pdata was the idiomatic form for platform data and this driver only uses DT-only so I'm finding pdata values everywhere really confusing) > + const char *label; > + int led_sources; > + u32 brightness; > + u32 max_brightness; > +}; > + > +static void lm3509_reset(struct lm3509_bl *data) > +{ > + if (data->reset_gpio) { > + gpiod_set_value(data->reset_gpio, 1); > + udelay(1); > + gpiod_set_value(data->reset_gpio, 0); > + udelay(10); > + } > +} > + > <snip> > + > +static struct backlight_device * > +lm3509_backlight_register(struct device *dev, const char *name_suffix, > + struct lm3509_bl *data, > + const struct backlight_ops *ops, > + const struct lm3509_bl_led_pdata *pdata) > + > +{ > + struct backlight_device *bd; > + struct backlight_properties props; > + const char *label = pdata->label; > + char name[64]; > + > + memset(&props, 0, sizeof(props)); > + props.type = BACKLIGHT_RAW; > + props.brightness = pdata->brightness; > + props.max_brightness = pdata->max_brightness; Please set props.scale appropriately for this device (given it only has 32 brightness levels I assume it is non-linear?). > + > + if (!label) { > + snprintf(name, sizeof(name), "lm3509-%s-%s", dev_name(dev), > + name_suffix); > + label = name; > + } > + > + bd = devm_backlight_device_register(dev, label, dev, data, ops, &props); > + if (bd) > + backlight_update_status(bd); > + > + return bd; > +} > + > <snip> > + > +static int lm3509_probe(struct i2c_client *client) > +{ > + struct lm3509_bl *data; > + struct device *dev = &client->dev; > + int ret; > + bool oled_mode = false; > + unsigned int reg_gp_val = 0; > + struct lm3509_bl_led_pdata pdata[LM3509_NUM_SINKS]; > + u32 rate_of_change = 0; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(dev, "i2c functionality check failed\n"); > + return -EOPNOTSUPP; > + } > + > + data = devm_kzalloc(dev, sizeof(struct lm3509_bl), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->regmap = devm_regmap_init_i2c(client, &lm3509_regmap); > + if (IS_ERR(data->regmap)) > + return PTR_ERR(data->regmap); > + i2c_set_clientdata(client, data); > + > + data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(data->reset_gpio)) > + return dev_err_probe(dev, PTR_ERR(data->reset_gpio), > + "Failed to get 'reset' gpio\n"); > + > + lm3509_reset(data); > + > + memset(pdata, 0, sizeof(pdata)); > + ret = lm3509_parse_dt_node(dev, pdata); > + if (ret) > + return ret; > + > + oled_mode = of_property_read_bool(dev->of_node, "ti,oled-mode"); > + > + if (!of_property_read_u32(dev->of_node, > + "ti,brightness-rate-of-change-us", > + &rate_of_change)) { > + switch (rate_of_change) { > + case 51: > + reg_gp_val = 0; > + break; > + case 13000: > + reg_gp_val = BIT(REG_GP_RMP1_BIT); > + break; > + case 26000: > + reg_gp_val = BIT(REG_GP_RMP0_BIT); > + break; > + case 52000: > + reg_gp_val = BIT(REG_GP_RMP0_BIT) | > + BIT(REG_GP_RMP1_BIT); > + break; > + default: > + dev_warn(dev, "invalid rate of change %u\n", > + rate_of_change); > + break; > + } > + } > + > + if (pdata[0].led_sources == > + (BIT(LM3509_SINK_MAIN) | BIT(LM3509_SINK_SUB))) > + reg_gp_val |= BIT(REG_GP_UNI_BIT); > + if (oled_mode) > + reg_gp_val |= BIT(REG_GP_OLED_BIT); > + > + ret = regmap_write(data->regmap, REG_GP, reg_gp_val); > + if (ret < 0) > + return ret; Is this the first time we write to the peripheral? If so the error path is probably worth a dev_err_probe() (I don't think regmap_write() logs anything on failure to write). > + if (pdata[0].led_sources) { > + data->bl_main = lm3509_backlight_register( > + dev, "main", data, &lm3509_main_ops, &pdata[0]); > + if (IS_ERR(data->bl_main)) { > + dev_err(dev, "failed to register main backlight\n"); > + return PTR_ERR(data->bl_main); This should use dev_err_probe(). > + } > + } > + > + if (pdata[1].led_sources) { > + data->bl_sub = lm3509_backlight_register( > + dev, "sub", data, &lm3509_sub_ops, &pdata[1]); > + if (IS_ERR(data->bl_sub)) { > + dev_err(dev, > + "failed to register secondary backlight\n"); > + return PTR_ERR(data->bl_sub); Another good place for dev_err_probe(). Daniel.
