[PATCH v2 03/10] i2c: meson: use i2c core for DT clock-frequency parsing

[Neil Armstrong]

On 03/09/2017 07:39 AM, Heiner Kallweit wrote:
> We don't have to parse the DT manually to retrieve the bus frequency
> and we don't have to maintain an own default for the bus frequency.
> Let the i2c core do this for us.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
> Reviewed-by: Jerome Brunet <jbrunet at baylibre.com>
> ---
> v2:
> - added Reviewed-by
> ---
>  drivers/i2c/busses/i2c-meson.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c
> index 50059d09..5e243efa 100644
> --- a/drivers/i2c/busses/i2c-meson.c
> +++ b/drivers/i2c/busses/i2c-meson.c
> @@ -38,7 +38,6 @@
>  #define REG_CTRL_CLKDIV_MASK	((BIT(10) - 1) << REG_CTRL_CLKDIV_SHIFT)
>  
>  #define I2C_TIMEOUT_MS		500
> -#define DEFAULT_FREQ		100000
>  
>  enum {
>  	TOKEN_END = 0,
> @@ -73,7 +72,7 @@ enum {
>   * @error:	Flag set when an error is received
>   * @lock:	To avoid race conditions between irq handler and xfer code
>   * @done:	Completion used to wait for transfer termination
> - * @frequency:	Operating frequency of I2C bus clock
> + * @timings:	Struct including the bus frequency
>   * @tokens:	Sequence of tokens to be written to the device
>   * @num_tokens:	Number of tokens
>   */
> @@ -92,7 +91,7 @@ struct meson_i2c {
>  
>  	spinlock_t		lock;
>  	struct completion	done;
> -	unsigned int		frequency;
> +	struct i2c_timings	timings;
>  	u32			tokens[2];
>  	int			num_tokens;
>  };
> @@ -136,12 +135,12 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c)
>  	unsigned long clk_rate = clk_get_rate(i2c->clk);
>  	unsigned int div;
>  
> -	div = DIV_ROUND_UP(clk_rate, i2c->frequency * 4);
> +	div = DIV_ROUND_UP(clk_rate, i2c->timings.bus_freq_hz * 4);
>  	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK,
>  			   div << REG_CTRL_CLKDIV_SHIFT);
>  
>  	dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__,
> -		clk_rate, i2c->frequency, div);
> +		clk_rate, i2c->timings.bus_freq_hz, div);
>  }
>  
>  static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len)
> @@ -396,9 +395,7 @@ static int meson_i2c_probe(struct platform_device *pdev)
>  	if (!i2c)
>  		return -ENOMEM;
>  
> -	if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> -				 &i2c->frequency))
> -		i2c->frequency = DEFAULT_FREQ;
> +	i2c_parse_fw_timings(&pdev->dev, &i2c->timings, true);
>  
>  	i2c->dev = &pdev->dev;
>  	platform_set_drvdata(pdev, i2c);
> 

Hi Heiner,

Please update the bindings in Documentation/devicetree/bindings/i2c/i2c-meson.txt
for these new optional attributes by adding :

---><-----
Please also refer to i2c.txt in this directory for common i2c
controller binding usage.
---><-----

With this additional patch :
Reviewed-by: Neil Armstrong <narmstrong at baylibre.com>

Neil