[PATCH v5 2/2] i2c: rk3x: add i2c support for rk3399 soc
From: heiko@sntech.de (Heiko Stübner)
Date: 2016-04-15 12:18:14
Also in:
linux-i2c, linux-rockchip, lkml
Hi David, Am Donnerstag, 17. M?rz 2016, 00:57:18 schrieb David Wu:
From: David Wu <redacted> - new method to caculate i2c timings for rk3399: There was an timing issue about "repeated start" time at the I2C controller of version0, controller appears to drop SDA at .875x (7/8) programmed clk high. On version 1 of the controller, the rule(.875x) isn't enough to meet tSU;STA requirements on 100k's Standard-mode. To resolve this issue, sda_update_config, start_setup_config and stop_setup_config for I2C timing information are added, new rules are designed to calculate the timing information at new v1. - pclk and function clk are separated at rk3399. - support i2c highspeed mode: 1.7MHz for rk3399 Signed-off-by: David Wu <redacted>
[...]
quoted hunk ↗ jump to hunk
@@ -83,11 +88,34 @@ enum rk3x_i2c_state { STATE_STOP }; +struct rk3x_i2c; + +/** + * struct rk3x_i2c_calced_timings: + * @div_low: Divider output for low + * @div_high: Divider output for high + * @sda_update_cfg: Used to config sda change state when scl is low, + * used to adjust setup/hold time + * @stp_sta_cfg: Start setup config for setup start time and hold starttime + * @stp_sto_cfg: Stop setup config for setup stop time + */ +struct rk3x_i2c_calced_timings { + unsigned long div_low; + unsigned long div_high; + unsigned int sda_update_cfg; + unsigned int stp_sta_cfg; + unsigned int stp_sto_cfg; +}; + /** * @grf_offset: offset inside the grf regmap for setting the i2c type */ struct rk3x_i2c_soc_data { int grf_offset; + + int (*clk_init)(struct rk3x_i2c *, unsigned long *); + int (*calc_timings)(unsigned long, struct i2c_timings *, + struct rk3x_i2c_calced_timings *); }; struct rk3x_i2c {@@ -97,11 +125,13 @@ struct rk3x_i2c { /* Hardware resources */ void __iomem *regs; - struct clk *clk; + struct clk *pclk; /* APB clock */ + struct clk *clk; /* Func clk for rk3399 or Func & APB clks for others */ struct notifier_block clk_rate_nb;
please use regular kernel-doc for the struct elements (aka @pclk: something) like some of the other fields already have. I can't spot anything else, but also don't know enough about i2c itself :-) Heiko