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i2c: rk3x: Fix data update point for 10K and less 10K speed

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Under the condition of 10K speed, data update point for data hold time
is calculated, which may exceed the maximum value 0x5, and the limit
is added to make its value within a reasonable range.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Change-Id: Ic9cc68c172dc8720f6fa0bbc9714ce33ea9dc608
This commit is contained in:
David Wu
2024-05-22 17:53:11 +08:00
committed by Tao Huang
parent 49eb03b277
commit eca19aef6a
1 changed files with 13 additions and 5 deletions
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18
drivers/i2c/busses/i2c-rk3x.c
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@@ -95,6 +95,11 @@ enum {
/* Disable i2c all irqs */
#define IEN_ALL_DISABLE 0
/* default data update point (0x3 + 1) */
#define DATA_UPDATE_POINT 0x3
#define START_SETUP_MAX 0x3
#define STOP_SETUP_MAX 0x3
#define REG_CON1_AUTO_STOP BIT(0)
#define REG_CON1_TRANSFER_AUTO_STOP BIT(1)
#define REG_CON1_NACK_AUTO_STOP BIT(2)
@@ -947,10 +952,10 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
}
/*
* calculate sda data hold count by the rules, data_upd_st:3
* is a appropriate value to reduce calculated times.
* calculate sda data hold count by the rules, data_upd_point = 3
* is a appropriate value to reduce calculated times, max is 0x5.
*/
for (sda_update_cfg = 3; sda_update_cfg > 0; sda_update_cfg--) {
for (sda_update_cfg = DATA_UPDATE_POINT; sda_update_cfg > 0; sda_update_cfg--) {
max_hold_data_ns = DIV_ROUND_UP((sda_update_cfg
* (t_calc->div_low) + 1)
* 1000000, clk_rate_khz);
@@ -961,16 +966,19 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
(min_setup_data_ns > spec->min_data_setup_ns))
break;
}
sda_update_cfg = (sda_update_cfg ? sda_update_cfg : 1) & DATA_UPDATE_POINT;
/* calculate setup start config */
/* calculate setup start config, min is over 1 by DIV_ROUND_UP */
min_setup_start_ns = t->scl_rise_ns + spec->min_setup_start_ns;
stp_sta_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_start_ns
- 1000000, 8 * 1000000 * (t_calc->div_high));
stp_sta_cfg = (stp_sta_cfg > START_SETUP_MAX) ? START_SETUP_MAX : stp_sta_cfg;
/* calculate setup stop config */
/* calculate setup stop config, min is over 1 by DIV_ROUND_UP */
min_setup_stop_ns = t->scl_rise_ns + spec->min_setup_stop_ns;
stp_sto_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_stop_ns
- 1000000, 8 * 1000000 * (t_calc->div_high));
stp_sto_cfg = (stp_sto_cfg > STOP_SETUP_MAX) ? STOP_SETUP_MAX : stp_sto_cfg;
t_calc->tuning = REG_CON_SDA_CFG(--sda_update_cfg) |
REG_CON_STA_CFG(--stp_sta_cfg) |