linux-kernel - Re: [PATCH] mfd: RK808: Fetch PMIC variant from chip id register

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Message-ID: <20160809095601.GY5243@dell>
Date:	Tue, 9 Aug 2016 10:56:01 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Wadim Egorov <w.egorov@...tec.de>
Cc:	linux-kernel@...r.kernel.org, linux-rockchip@...ts.infradead.org,
	andy.yan@...k-chips.com
Subject: Re: [PATCH] mfd: RK808: Fetch PMIC variant from chip id register

On Thu, 14 Jul 2016, Wadim Egorov wrote:

> Add and use the chip id registers to determine the PMIC variant.

Yes, much better.

Interrogating the h/w for its model/version number is always
preferred.

Applied, thanks.

> Signed-off-by: Wadim Egorov <w.egorov@...tec.de>
> ---
> 
> This patch is based on top of
> 
> [v6,1/5] mfd: RK808: Add RK818 support
> (https://patchwork.kernel.org/patch/9172223/)
> 
> ---
>  drivers/mfd/rk808.c       | 17 +++++++++--------
>  include/linux/mfd/rk808.h |  6 ++++--
>  2 files changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
> index 66f7b08..fbec1d8 100644
> --- a/drivers/mfd/rk808.c
> +++ b/drivers/mfd/rk808.c
> @@ -291,8 +291,8 @@ static void rk808_device_shutdown(void)
>  }
>  
>  static const struct of_device_id rk808_of_match[] = {
> -	{ .compatible = "rockchip,rk808", .data = (void *) RK808_ID },
> -	{ .compatible = "rockchip,rk818", .data = (void *) RK818_ID },
> +	{ .compatible = "rockchip,rk808" },
> +	{ .compatible = "rockchip,rk818" },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(of, rk808_of_match);
> @@ -302,7 +302,6 @@ static int rk808_probe(struct i2c_client *client,
>  {
>  	struct device_node *np = client->dev.of_node;
>  	struct rk808 *rk808;
> -	const struct of_device_id *match;
>  	const struct rk808_reg_data *pre_init_reg;
>  	const struct mfd_cell *cells;
>  	int nr_pre_init_regs;
> @@ -315,12 +314,14 @@ static int rk808_probe(struct i2c_client *client,
>  	if (!rk808)
>  		return -ENOMEM;
>  
> -	match = of_match_device(rk808_of_match, &client->dev);
> -	if (!match) {
> -		dev_err(&client->dev, "Unable to match OF ID\n");
> -		return -ENODEV;
> +	rk808->variant = i2c_smbus_read_word_data(client, RK808_ID_MSB);
> +	if (rk808->variant < 0) {
> +		dev_err(&client->dev, "Failed to read the chip id at 0x%02x\n",
> +			RK808_ID_MSB);
> +		return rk808->variant;
>  	}
> -	rk808->variant = (long)match->data;
> +
> +	dev_dbg(&client->dev, "Chip id: 0x%x\n", (unsigned int)rk808->variant);
>  
>  	switch (rk808->variant) {
>  	case RK808_ID:
> diff --git a/include/linux/mfd/rk808.h b/include/linux/mfd/rk808.h
> index e5ae21d..fc5db6f 100644
> --- a/include/linux/mfd/rk808.h
> +++ b/include/linux/mfd/rk808.h
> @@ -69,6 +69,8 @@ enum rk808_reg {
>  #define RK808_RTC_INT_REG	0x12
>  #define RK808_RTC_COMP_LSB_REG	0x13
>  #define RK808_RTC_COMP_MSB_REG	0x14
> +#define RK808_ID_MSB		0x17
> +#define RK808_ID_LSB		0x18
>  #define RK808_CLK32OUT_REG	0x20
>  #define RK808_VB_MON_REG	0x21
>  #define RK808_THERMAL_REG	0x22
> @@ -318,8 +320,8 @@ enum {
>  };
>  
>  enum {
> -	RK808_ID,
> -	RK818_ID,
> +	RK808_ID = 0x0000,
> +	RK818_ID = 0x8181,
>  };
>  
>  struct rk808 {

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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