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authorPierre-Yves MORDRET <pierre-yves.mordret@st.com>2018-11-19 12:03:32 +0100
committerWolfram Sang <wsa@the-dreams.de>2018-11-27 13:08:17 +0100
commitcb944fb973bcd326bc99a5381f5fb109c0b9de95 (patch)
treebb8982c27c797877ed55da9aa946813be28a8114 /drivers/i2c
parent9d9aa7ec7baf62640cd4e1a869746b2356731e93 (diff)
downloadlinux-cb944fb973bcd326bc99a5381f5fb109c0b9de95.tar.bz2
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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-stm32f7.c38
1 files changed, 35 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 62d023e737d9..e9f0c0bd774d 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -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)) {