Re: [PATCH v2 1/4] leds: pca955x: add device tree support

[Jacek Anaszewski <jacek.anaszewski-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi Cedric,

Thanks for the updated patch set.
Please refer below to my comments.

On 08/01/2017 02:09 PM, Cédric Le Goater wrote:
> It will be used in a following patch to define different operation
> modes for each pin.
> 
> Signed-off-by: Cédric Le Goater <clg-Bxea+6Xhats@public.gmane.org>
> ---
>  drivers/leds/leds-pca955x.c | 89 ++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 84 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
> index 9a873118ea5f..3afd481a760f 100644
> --- a/drivers/leds/leds-pca955x.c
> +++ b/drivers/leds/leds-pca955x.c
> @@ -41,14 +41,17 @@
>   */
>  
>  #include <linux/acpi.h>
> -#include <linux/module.h>
> -#include <linux/delay.h>
> -#include <linux/string.h>
>  #include <linux/ctype.h>
> -#include <linux/leds.h>
> +#include <linux/delay.h>
>  #include <linux/err.h>
> +#include <linux/gpio.h>
>  #include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of.h>
>  #include <linux/slab.h>
> +#include <linux/string.h>
>  
>  /* LED select registers determine the source that drives LED outputs */
>  #define PCA955X_LS_LED_ON	0x0	/* Output LOW */
> @@ -122,6 +125,12 @@ struct pca955x_led {
>  	struct led_classdev	led_cdev;
>  	int			led_num;	/* 0 .. 15 potentially */
>  	char			name[32];
> +	const char		*default_trigger;
> +};
> +
> +struct pca955x_platform_data {
> +	struct pca955x_led	*leds;
> +	int			num_leds;
>  };
>  
>  /* 8 bits per input register */
> @@ -250,6 +259,70 @@ static int pca955x_led_set(struct led_classdev *led_cdev,
>  	return 0;
>  }
>  
> +#if IS_ENABLED(CONFIG_OF)
> +static struct pca955x_platform_data *
> +pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
> +{
> +	struct device_node *np = client->dev.of_node;
> +	struct device_node *child;
> +	struct pca955x_platform_data *pdata;
> +	int count;
> +
> +	count = of_get_child_count(np);
> +	if (!count || count > chip->bits)
> +		return ERR_PTR(-ENODEV);
> +
> +	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		return ERR_PTR(-ENOMEM);
> +
> +	pdata->leds = devm_kzalloc(&client->dev,
> +				   sizeof(struct pca955x_led) * chip->bits,
> +				   GFP_KERNEL);
> +	if (!pdata->leds)
> +		return ERR_PTR(-ENOMEM);
> +
> +	for_each_child_of_node(np, child) {
> +		const char *name;
> +		u32 reg;
> +		int res;
> +
> +		res = of_property_read_u32(child, "reg", &reg);
> +		if ((res != 0) || (reg >= chip->bits))
> +			continue;
> +
> +		if (of_property_read_string(child, "label", &name))
> +			name = child->name;
> +
> +		snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
> +			 "%s", name);
> +
> +		of_property_read_string(child, "linux,default-trigger",
> +					&pdata->leds[reg].default_trigger);
> +	}
> +
> +	pdata->num_leds = chip->bits;
> +
> +	return pdata;
> +}
> +
> +static const struct of_device_id of_pca955x_match[] = {
> +	{ .compatible = "nxp,pca9550", .data = (void *)pca9550 },
> +	{ .compatible = "nxp,pca9551", .data = (void *)pca9551 },
> +	{ .compatible = "nxp,pca9552", .data = (void *)pca9552 },
> +	{ .compatible = "nxp,pca9553", .data = (void *)pca9553 },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, of_pca955x_match);
> +#else
> +static struct pca955x_platform_data *
> +pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
> +{
> +	return ERR_PTR(-ENODEV);
> +}
> +#endif
> +
>  static int pca955x_probe(struct i2c_client *client,
>  					const struct i2c_device_id *id)
>  {
> @@ -257,8 +330,8 @@ static int pca955x_probe(struct i2c_client *client,
>  	struct pca955x_led *pca955x_led;
>  	struct pca955x_chipdef *chip;
>  	struct i2c_adapter *adapter;
> -	struct led_platform_data *pdata;
>  	int i, err;
> +	struct pca955x_platform_data *pdata;
>  
>  	if (id) {
>  		chip = &pca955x_chipdefs[id->driver_data];
> @@ -272,6 +345,11 @@ static int pca955x_probe(struct i2c_client *client,
>  	}
>  	adapter = to_i2c_adapter(client->dev.parent);
>  	pdata = dev_get_platdata(&client->dev);
> +	if (!pdata) {
> +		pdata =	pca955x_pdata_of_init(client, chip);
> +		if (IS_ERR(pdata))
> +			return PTR_ERR(pdata);
> +	}

Since from this moment pdata should be in every case available you
could get rid of "if (pdata) check" right after

"if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))".



>  	/* Make sure the slave address / chip type combo given is possible */
>  	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
> @@ -378,6 +456,7 @@ static struct i2c_driver pca955x_driver = {
>  	.driver = {
>  		.name	= "leds-pca955x",
>  		.acpi_match_table = ACPI_PTR(pca955x_acpi_ids),
> +		.of_match_table = of_match_ptr(of_pca955x_match),
>  	},
>  	.probe	= pca955x_probe,
>  	.remove	= pca955x_remove,
> 

-- 
Best regards,
Jacek Anaszewski
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