diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c
index 7d046c1a1e6..fc5c1221e1e 100644
--- a/drivers/i2c/stm32f7_i2c.c
+++ b/drivers/i2c/stm32f7_i2c.c
@@ -7,10 +7,10 @@
#include <clk.h>
#include <dm.h>
#include <i2c.h>
-#include <malloc.h>
#include <reset.h>
#include <dm/device.h>
+#include <linux/err.h>
#include <linux/io.h>
/* STM32 I2C registers */
@@ -145,7 +145,6 @@ struct stm32_i2c_spec {
/**
* struct stm32_i2c_setup - private I2C timing setup parameters
- * @speed: I2C speed mode (standard, Fast Plus)
* @speed_freq: I2C speed frequency (Hz)
* @clock_src: I2C clock source frequency (Hz)
* @rise_time: Rise time (ns)
@@ -154,7 +153,6 @@ struct stm32_i2c_spec {
* @analog_filter: Analog filter delay (On/Off)
*/
struct stm32_i2c_setup {
- enum i2c_speed_mode speed;
u32 speed_freq;
u32 clock_src;
u32 rise_time;
@@ -184,10 +182,11 @@ struct stm32_i2c_priv {
struct stm32_i2c_regs *regs;
struct clk clk;
struct stm32_i2c_setup *setup;
- int speed;
+ u32 speed;
};
static const struct stm32_i2c_spec i2c_specs[] = {
+ /* Standard speed - 100 KHz */
[IC_SPEED_MODE_STANDARD] = {
.rate = I2C_SPEED_STANDARD_RATE,
.rate_min = 8000,
@@ -200,6 +199,7 @@ static const struct stm32_i2c_spec i2c_specs[] = {
.l_min = 4700,
.h_min = 4000,
},
+ /* Fast speed - 400 KHz */
[IC_SPEED_MODE_FAST] = {
.rate = I2C_SPEED_FAST_RATE,
.rate_min = 320000,
@@ -212,6 +212,7 @@ static const struct stm32_i2c_spec i2c_specs[] = {
.l_min = 1300,
.h_min = 600,
},
+ /* Fast Plus Speed - 1 MHz */
[IC_SPEED_MODE_FAST_PLUS] = {
.rate = I2C_SPEED_FAST_PLUS_RATE,
.rate_min = 800000,
@@ -474,6 +475,7 @@ static int stm32_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
}
static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup,
+ const struct stm32_i2c_spec *specs,
struct list_head *solutions)
{
struct stm32_i2c_timings *v;
@@ -490,13 +492,13 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup,
af_delay_max = setup->analog_filter ?
STM32_I2C_ANALOG_FILTER_DELAY_MAX : 0;
- sdadel_min = i2c_specs[setup->speed].hddat_min + setup->fall_time -
+ sdadel_min = specs->hddat_min + setup->fall_time -
af_delay_min - (setup->dnf + 3) * i2cclk;
- sdadel_max = i2c_specs[setup->speed].vddat_max - setup->rise_time -
+ sdadel_max = specs->vddat_max - setup->rise_time -
af_delay_max - (setup->dnf + 4) * i2cclk;
- scldel_min = setup->rise_time + i2c_specs[setup->speed].sudat_min;
+ scldel_min = setup->rise_time + specs->sudat_min;
if (sdadel_min < 0)
sdadel_min = 0;
@@ -548,6 +550,7 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup,
}
static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
+ const struct stm32_i2c_spec *specs,
struct list_head *solutions,
struct stm32_i2c_timings *s)
{
@@ -570,8 +573,8 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
dnf_delay = setup->dnf * i2cclk;
tsync = af_delay_min + dnf_delay + (2 * i2cclk);
- clk_max = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_min;
- clk_min = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_max;
+ clk_max = STM32_NSEC_PER_SEC / specs->rate_min;
+ clk_min = STM32_NSEC_PER_SEC / specs->rate_max;
/*
* Among Prescaler possibilities discovered above figures out SCL Low
@@ -589,7 +592,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
for (l = 0; l < STM32_SCLL_MAX; l++) {
u32 tscl_l = (l + 1) * prescaler + tsync;
- if ((tscl_l < i2c_specs[setup->speed].l_min) ||
+ if (tscl_l < specs->l_min ||
(i2cclk >=
((tscl_l - af_delay_min - dnf_delay) / 4))) {
continue;
@@ -601,7 +604,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
setup->rise_time + setup->fall_time;
if ((tscl >= clk_min) && (tscl <= clk_max) &&
- (tscl_h >= i2c_specs[setup->speed].h_min) &&
+ (tscl_h >= specs->h_min) &&
(i2cclk < tscl_h)) {
u32 clk_error;
@@ -630,26 +633,40 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
return ret;
}
+static const struct stm32_i2c_spec *get_specs(u32 rate)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(i2c_specs); i++)
+ if (rate <= i2c_specs[i].rate)
+ return &i2c_specs[i];
+
+ /* NOT REACHED */
+ return ERR_PTR(-EINVAL);
+}
+
static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv,
struct stm32_i2c_setup *setup,
struct stm32_i2c_timings *output)
{
+ const struct stm32_i2c_spec *specs;
struct stm32_i2c_timings *v, *_v;
struct list_head solutions;
int ret;
- if (setup->speed >= ARRAY_SIZE(i2c_specs)) {
- pr_err("%s: speed out of bound {%d/%d}\n", __func__,
- setup->speed, ARRAY_SIZE(i2c_specs) - 1);
+ specs = get_specs(setup->speed_freq);
+ if (specs == ERR_PTR(-EINVAL)) {
+ pr_err("%s: speed out of bound {%d}\n", __func__,
+ setup->speed_freq);
return -EINVAL;
}
- if ((setup->rise_time > i2c_specs[setup->speed].rise_max) ||
- (setup->fall_time > i2c_specs[setup->speed].fall_max)) {
+ if (setup->rise_time > specs->rise_max ||
+ setup->fall_time > specs->fall_max) {
pr_err("%s :timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
__func__,
- setup->rise_time, i2c_specs[setup->speed].rise_max,
- setup->fall_time, i2c_specs[setup->speed].fall_max);
+ setup->rise_time, specs->rise_max,
+ setup->fall_time, specs->fall_max);
return -EINVAL;
}
@@ -659,18 +676,12 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv,
return -EINVAL;
}
- if (setup->speed_freq > i2c_specs[setup->speed].rate) {
- pr_err("%s: Freq {%d/%d}\n", __func__,
- setup->speed_freq, i2c_specs[setup->speed].rate);
- return -EINVAL;
- }
-
INIT_LIST_HEAD(&solutions);
- ret = stm32_i2c_compute_solutions(setup, &solutions);
+ ret = stm32_i2c_compute_solutions(setup, specs, &solutions);
if (ret)
goto exit;
- ret = stm32_i2c_choose_solution(setup, &solutions, output);
+ ret = stm32_i2c_choose_solution(setup, specs, &solutions, output);
if (ret)
goto exit;
@@ -689,14 +700,24 @@ exit:
return ret;
}
+static u32 get_lower_rate(u32 rate)
+{
+ int i;
+
+ for (i = ARRAY_SIZE(i2c_specs) - 1; i >= 0; i--)
+ if (rate > i2c_specs[i].rate)
+ return i2c_specs[i].rate;
+
+ return i2c_specs[0].rate;
+}
+
static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv,
struct stm32_i2c_timings *timing)
{
struct stm32_i2c_setup *setup = i2c_priv->setup;
int ret = 0;
- setup->speed = i2c_priv->speed;
- setup->speed_freq = i2c_specs[setup->speed].rate;
+ setup->speed_freq = i2c_priv->speed;
setup->clock_src = clk_get_rate(&i2c_priv->clk);
if (!setup->clock_src) {
@@ -709,13 +730,11 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv,
if (ret) {
debug("%s: failed to compute I2C timings.\n",
__func__);
- if (i2c_priv->speed > IC_SPEED_MODE_STANDARD) {
- i2c_priv->speed--;
- setup->speed = i2c_priv->speed;
+ if (setup->speed_freq > I2C_SPEED_STANDARD_RATE) {
setup->speed_freq =
- i2c_specs[setup->speed].rate;
+ get_lower_rate(setup->speed_freq);
debug("%s: downgrade I2C Speed Freq to (%i)\n",
- __func__, i2c_specs[setup->speed].rate);
+ __func__, setup->speed_freq);
} else {
break;
}
@@ -727,13 +746,15 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv,
return ret;
}
- debug("%s: I2C Speed(%i), Freq(%i), Clk Source(%i)\n", __func__,
- setup->speed, setup->speed_freq, setup->clock_src);
+ debug("%s: I2C Freq(%i), Clk Source(%i)\n", __func__,
+ setup->speed_freq, setup->clock_src);
debug("%s: I2C Rise(%i) and Fall(%i) Time\n", __func__,
setup->rise_time, setup->fall_time);
debug("%s: I2C Analog Filter(%s), DNF(%i)\n", __func__,
setup->analog_filter ? "On" : "Off", setup->dnf);
+ i2c_priv->speed = setup->speed_freq;
+
return 0;
}
@@ -773,21 +794,13 @@ static int stm32_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct stm32_i2c_priv *i2c_priv = dev_get_priv(bus);
- switch (speed) {
- case I2C_SPEED_STANDARD_RATE:
- i2c_priv->speed = IC_SPEED_MODE_STANDARD;
- break;
- case I2C_SPEED_FAST_RATE:
- i2c_priv->speed = IC_SPEED_MODE_FAST;
- break;
- case I2C_SPEED_FAST_PLUS_RATE:
- i2c_priv->speed = IC_SPEED_MODE_FAST_PLUS;
- break;
- default:
+ if (speed > I2C_SPEED_FAST_PLUS_RATE) {
debug("%s: Speed %d not supported\n", __func__, speed);
return -EINVAL;
}
+ i2c_priv->speed = speed;
+
return stm32_i2c_hw_config(i2c_priv);
}