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@xxxxxxxxx>
>> Reviewed-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxxx>
>
> Neil
>
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