i2c: stm32f7: SYSCFG Fast Mode Plus support for I2C STM32F7

Read SYSCFG bindings to set Fast Mode Plus bits if Fast Mode Plus
speed is selected.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Pierre-Yves MORDRET 2018-11-19 12:03:32 +01:00 committed by Wolfram Sang
parent 9d9aa7ec7b
commit cb944fb973
1 changed files with 35 additions and 3 deletions

View File

@ -21,12 +21,14 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/slab.h>
@ -276,6 +278,7 @@ struct stm32f7_i2c_msg {
* slave)
* @dma: dma data
* @use_dma: boolean to know if dma is used in the current transfer
* @regmap: holds SYSCFG phandle for Fast Mode Plus bits
*/
struct stm32f7_i2c_dev {
struct i2c_adapter adap;
@ -296,6 +299,7 @@ struct stm32f7_i2c_dev {
bool master_mode;
struct stm32_i2c_dma *dma;
bool use_dma;
struct regmap *regmap;
};
/**
@ -1763,6 +1767,30 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
return 0;
}
static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
struct stm32f7_i2c_dev *i2c_dev)
{
struct device_node *np = pdev->dev.of_node;
int ret;
u32 reg, mask;
i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
if (IS_ERR(i2c_dev->regmap)) {
/* Optional */
return 0;
}
ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1, &reg);
if (ret)
return ret;
ret = of_property_read_u32_index(np, "st,syscfg-fmp", 2, &mask);
if (ret)
return ret;
return regmap_update_bits(i2c_dev->regmap, reg, mask, mask);
}
static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
@ -1828,12 +1856,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
ret = device_property_read_u32(&pdev->dev, "clock-frequency",
&clk_rate);
if (!ret && clk_rate >= 1000000)
if (!ret && clk_rate >= 1000000) {
i2c_dev->speed = STM32_I2C_SPEED_FAST_PLUS;
else if (!ret && clk_rate >= 400000)
ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
if (ret)
goto clk_free;
} else if (!ret && clk_rate >= 400000) {
i2c_dev->speed = STM32_I2C_SPEED_FAST;
else if (!ret && clk_rate >= 100000)
} else if (!ret && clk_rate >= 100000) {
i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
}
rst = devm_reset_control_get(&pdev->dev, NULL);
if (IS_ERR(rst)) {