i2c: designware_i2c: Add spike supression

Some versions of this peripheral include a spike-suppression phase of the
bus. Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
This commit is contained in:
Simon Glass 2020-01-23 11:48:15 -07:00 committed by Heiko Schocher
parent e71b6f6622
commit 96fe11c3da
3 changed files with 13 additions and 1 deletions

View File

@ -220,6 +220,7 @@ static unsigned int __dw_i2c_set_bus_speed(struct dw_i2c *priv,
enum i2c_speed_mode i2c_spd;
unsigned int cntl;
unsigned int ena;
int spk_cnt;
int ret;
if (priv)
@ -241,6 +242,13 @@ static unsigned int __dw_i2c_set_bus_speed(struct dw_i2c *priv,
cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
/* Get the proper spike-suppression count based on target speed */
if (!priv || !priv->has_spk_cnt)
spk_cnt = 0;
else if (i2c_spd >= IC_SPEED_MODE_HIGH)
spk_cnt = readl(&i2c_base->hs_spklen);
else
spk_cnt = readl(&i2c_base->fs_spklen);
if (scl_sda_cfg) {
config.sda_hold = scl_sda_cfg->sda_hold;
if (i2c_spd == IC_SPEED_MODE_STANDARD) {
@ -251,7 +259,7 @@ static unsigned int __dw_i2c_set_bus_speed(struct dw_i2c *priv,
config.scl_lcnt = scl_sda_cfg->fs_lcnt;
}
} else {
ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, 0,
ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, spk_cnt,
&config);
if (ret)
return log_msg_ret("gen_confg", ret);

View File

@ -176,6 +176,7 @@ struct dw_scl_sda_cfg {
* @scl_rise_time_ns: Configured SCL rise time in nanoseconds
* @scl_fall_time_ns: Configured SCL fall time in nanoseconds
* @sda_hold_time_ns: Configured SDA hold time in nanoseconds
* @has_spk_cnt: true if the spike-count register is present
* @clk: Clock input to the I2C controller
*/
struct dw_i2c {
@ -185,6 +186,7 @@ struct dw_i2c {
u32 scl_rise_time_ns;
u32 scl_fall_time_ns;
u32 sda_hold_time_ns;
bool has_spk_cnt;
#if CONFIG_IS_ENABLED(CLK)
struct clk clk;
#endif

View File

@ -62,6 +62,8 @@ static int designware_i2c_pci_ofdata_to_platdata(struct udevice *dev)
if (IS_ENABLED(CONFIG_INTEL_BAYTRAIL))
/* Use BayTrail specific timing values */
priv->scl_sda_cfg = &byt_config;
if (dev_get_driver_data(dev) == INTEL_APL)
priv->has_spk_cnt = true;
return designware_i2c_ofdata_to_platdata(dev);
}