[PATCH v3 1/4] i2c: rk3x: switch to i2c generic dt parsing
From: Andy Shevchenko <hidden>
Date: 2016-01-14 13:05:20
Also in:
linux-gpio, linux-rockchip, lkml
On Thu, Jan 14, 2016 at 2:31 PM, David Wu [off-list ref] wrote:
Switch to the new generic functions: i2c_parse_fw_timings().
Nice one! Reviwed-by: Andy Shevchenko [off-list ref] Minor comments below.
quoted hunk ↗ jump to hunk
--- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c
quoted hunk ↗ jump to hunk
@@ -437,10 +434,7 @@ out: * Calculate divider values for desired SCL frequency * * @clk_rate: I2C input clock rate - * @scl_rate: Desired SCL rate - * @scl_rise_ns: How many ns it takes for SCL to rise. - * @scl_fall_ns: How many ns it takes for SCL to fall. - * @sda_fall_ns: How many ns it takes for SDA to fall. + * @t_input: Known I2C timing information.
Perhaps t_input -> t.
quoted hunk ↗ jump to hunk
* @div_low: Divider output for low * @div_high: Divider output for high *@@ -448,11 +442,10 @@ out: * a best-effort divider value is returned in divs. If the target rate is * too high, we silently use the highest possible rate. */ -static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, - unsigned long scl_rise_ns, - unsigned long scl_fall_ns, - unsigned long sda_fall_ns, - unsigned long *div_low, unsigned long *div_high) +static int rk3x_i2c_calc_divs(unsigned long clk_rate, + struct i2c_timings *t_input,
Ditto.
+ unsigned long *div_low,
+ unsigned long *div_high)
{
unsigned long spec_min_low_ns, spec_min_high_ns;
unsigned long spec_setup_start, spec_max_data_hold_ns;quoted hunk ↗ jump to hunk
@@ -517,18 +510,19 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate, * we meet tSU;STA and tHD;STA times. */ min_high_ns = max(min_high_ns, - DIV_ROUND_UP((scl_rise_ns + spec_setup_start) * 1000, 875)); + DIV_ROUND_UP((t_input->scl_rise_ns + spec_setup_start) * 1000, + 875));
To one line (after above change).
min_high_ns = max(min_high_ns, - DIV_ROUND_UP((scl_rise_ns + spec_setup_start + - sda_fall_ns + spec_min_high_ns), 2)); + DIV_ROUND_UP((t_input->scl_rise_ns + spec_setup_start + + t_input->sda_fall_ns + spec_min_high_ns), 2));
Ditto.
quoted hunk ↗ jump to hunk
@@ -620,10 +614,8 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate) u64 t_low_ns, t_high_ns; int ret; - ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, i2c->scl_rise_ns, - i2c->scl_fall_ns, i2c->sda_fall_ns, - &div_low, &div_high); - WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->scl_frequency); + ret = rk3x_i2c_calc_divs(clk_rate, &i2c->t, &div_low, &div_high); + WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->t.bus_freq_hz);
I would recommend to struct i2c_timings *t = &i2c->t; + ret = rk3x_i2c_calc_divs(clk_rate, t, &div_low, &div_high); + WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz);
quoted hunk ↗ jump to hunk
@@ -634,7 +626,7 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate) dev_dbg(i2c->dev, "CLK %lukhz, Req %uns, Act low %lluns high %lluns\n", clk_rate / 1000, - 1000000000 / i2c->scl_frequency, + 1000000000 / i2c->t.bus_freq_hz,
Ditto. -- With Best Regards, Andy Shevchenko