Commit a80f2494 authored by Qii Wang's avatar Qii Wang Committed by Wolfram Sang
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i2c: mediatek: Use scl_int_delay_ns to compensate clock-stretching 



The parameters of tSU,STA/tHD,STA/tSU,STOP maybe out of spec due
to device clock-stretch or circuit loss, we could get a suitable
scl_int_delay_ns from i2c_timings to compensate these parameters
to meet the spec via EXT_CONF register.

Signed-off-by: default avatarQii Wang <qii.wang@mediatek.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 3186b880

drivers/i2c/busses/i2c-mt65xx.c

+5 −1
Original line number Diff line number Diff line
@@ -231,6 +231,7 @@ struct mtk_i2c { 
	struct i2c_adapter adap;	/* i2c host adapter */

	struct device *dev;

	struct completion msg_complete;

	struct i2c_timings timing_info;



	/* set in i2c probe */

	void __iomem *base;		/* i2c base addr */
@@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, 
	else

		clk_ns = sample_ns / 2;



	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns);

	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns +

				  i2c->timing_info.scl_int_delay_ns, clk_ns);

	if (su_sta_cnt > max_sta_cnt)

		return -1;
@@ -1176,6 +1178,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) 
	i2c->use_push_pull =

		of_property_read_bool(np, "mediatek,use-push-pull");



	i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true);



	return 0;

}