On 25/07/2018 17:39:30+0300, Andy Shevchenko wrote:
> Instead of using custom variables and parser, convert the driver to use
> the ones provided by I2C core.
>
> No functional change intended.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Tested-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-at91.c | 24 ++++++++----------------
> 1 file changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
> index 3f3e8b3bf5ff..c83caa383cd2 100644
> --- a/drivers/i2c/busses/i2c-at91.c
> +++ b/drivers/i2c/busses/i2c-at91.c
> @@ -34,7 +34,6 @@
> #include <linux/pm_runtime.h>
> #include <linux/pinctrl/consumer.h>
>
> -#define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */
> #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
> #define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */
> #define AUTOSUSPEND_TIMEOUT 2000
> @@ -190,16 +189,18 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev)
> * Calculate symmetric clock as stated in datasheet:
> * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset))
> */
> -static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
> +static void at91_calc_twi_clock(struct at91_twi_dev *dev)
> {
> int ckdiv, cdiv, div, hold = 0;
> struct at91_twi_pdata *pdata = dev->pdata;
> int offset = pdata->clk_offset;
> int max_ckdiv = pdata->clk_max_div;
> - u32 twd_hold_time_ns = 0;
> + struct i2c_timings timings, *t = &timings;
> +
> + i2c_parse_fw_timings(dev->dev, t, true);
>
> div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk),
> - 2 * twi_clk) - offset);
> + 2 * t->bus_freq_hz) - offset);
> ckdiv = fls(div >> 8);
> cdiv = div >> ckdiv;
>
> @@ -211,15 +212,12 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
> }
>
> if (pdata->has_hold_field) {
> - of_property_read_u32(dev->dev->of_node, "i2c-sda-hold-time-ns",
> - &twd_hold_time_ns);
> -
> /*
> * hold time = HOLD + 3 x T_peripheral_clock
> * Use clk rate in kHz to prevent overflows when computing
> * hold.
> */
> - hold = DIV_ROUND_UP(twd_hold_time_ns
> + hold = DIV_ROUND_UP(t->sda_hold_ns
> * (clk_get_rate(dev->clk) / 1000), 1000000);
> hold -= 3;
> if (hold < 0)
> @@ -236,7 +234,7 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
> | AT91_TWI_CWGR_HOLD(hold);
>
> dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns)\n",
> - cdiv, ckdiv, hold, twd_hold_time_ns);
> + cdiv, ckdiv, hold, t->sda_hold_ns);
> }
>
> static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)
> @@ -1052,7 +1050,6 @@ static int at91_twi_probe(struct platform_device *pdev)
> struct resource *mem;
> int rc;
> u32 phy_addr;
> - u32 bus_clk_rate;
>
> dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> if (!dev)
> @@ -1108,12 +1105,7 @@ static int at91_twi_probe(struct platform_device *pdev)
> dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size);
> }
>
> - rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
> - &bus_clk_rate);
> - if (rc)
> - bus_clk_rate = DEFAULT_TWI_CLK_HZ;
> -
> - at91_calc_twi_clock(dev, bus_clk_rate);
> + at91_calc_twi_clock(dev);
> at91_init_twi_bus(dev);
>
> snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
> --
> 2.18.0
>
--
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
