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

Submitted by Heiner Kallweit on March 9, 2017, 6:39 a.m.

Details

Message ID 1b175225-9cb1-6c7c-3175-dcba8189fefe@gmail.com
State Superseded
Headers show

Commit Message

Heiner Kallweit March 9, 2017, 6:39 a.m.
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@gmail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
---
v2:
- added Reviewed-by
---
 drivers/i2c/busses/i2c-meson.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

Comments

Neil Armstrong March 9, 2017, 8:26 a.m.
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@gmail.com>
> Reviewed-by: Jerome Brunet <jbrunet@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@baylibre.com>

Neil
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Heiner Kallweit March 9, 2017, 8:13 p.m.
Am 09.03.2017 um 09:26 schrieb 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@gmail.com>
>> Reviewed-by: Jerome Brunet <jbrunet@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 :
> 
Hi Neil,

not sure which new attributes you mean. i2c_parse_fw_timings parses additional
attributes (apart from bus frequency), that right. But they are not used by
the driver and therefore effectively aren't supported.

Heiner

> ---><-----
> Please also refer to i2c.txt in this directory for common i2c
> controller binding usage.
> ---><-----
> 
> With this additional patch :
> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
> 
> Neil
> 

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Patch hide | download patch | download mbox

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);