i2c: stm32f7: add a new st, stm32mp15-i2c compatible

Add a new stm32mp15 specific compatible to handle FastMode+
registers handling which is different on the stm32mp15 compared
to the stm32f7 or stm32h7.
Indeed, on the stm32mp15, the FastMode+ set and clear registers
are separated while on the other platforms (F7 or H7) the control
is done in a unique register.

Signed-off-by: Alain Volmat <[e-mail]>
Reviewed-by: Pierre-Yves MORDRET <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/busses/i2c-stm32f7.c

···
  * @fall_time: Fall time (ns)
  * @dnf: Digital filter coefficient (0-16)
  * @analog_filter: Analog filter delay (On/Off)
+ * @fmp_clr_offset: Fast Mode Plus clear register offset from set register
  */
 struct stm32f7_i2c_setup {
 	enum stm32_i2c_speed speed;
···
 	u32 fall_time;
 	u8 dnf;
 	bool analog_filter;
+	u32 fmp_clr_offset;
 };
 
 /**
···
  * @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
- * @fmp_reg: register address for setting Fast Mode Plus bits
+ * @fmp_sreg: register address for setting Fast Mode Plus bits
+ * @fmp_creg: register address for clearing Fast Mode Plus bits
  * @fmp_mask: mask for Fast Mode Plus bits in set register
  * @wakeup_src: boolean to know if the device is a wakeup source
  */
···
 	struct stm32_i2c_dma *dma;
 	bool use_dma;
 	struct regmap *regmap;
-	u32 fmp_reg;
+	u32 fmp_sreg;
+	u32 fmp_creg;
 	u32 fmp_mask;
 	bool wakeup_src;
 };
···
 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
 	.dnf = STM32F7_I2C_DNF_DEFAULT,
 	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
+};
+
+static const struct stm32f7_i2c_setup stm32mp15_setup = {
+	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
+	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
+	.dnf = STM32F7_I2C_DNF_DEFAULT,
+	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
+	.fmp_clr_offset = 0x40,
 };
 
 static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
···
 static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
 					  bool enable)
 {
+	int ret;
+
 	if (i2c_dev->speed != STM32_I2C_SPEED_FAST_PLUS ||
 	    IS_ERR_OR_NULL(i2c_dev->regmap))
 		/* Optional */
 		return 0;
 
-	return regmap_update_bits(i2c_dev->regmap, i2c_dev->fmp_reg,
-				  i2c_dev->fmp_mask,
-				  enable ? i2c_dev->fmp_mask : 0);
+	if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg)
+		ret = regmap_update_bits(i2c_dev->regmap,
+					 i2c_dev->fmp_sreg,
+					 i2c_dev->fmp_mask,
+					 enable ? i2c_dev->fmp_mask : 0);
+	else
+		ret = regmap_write(i2c_dev->regmap,
+				   enable ? i2c_dev->fmp_sreg :
+					    i2c_dev->fmp_creg,
+				   i2c_dev->fmp_mask);
+
+	return ret;
 }
 
 static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
···
 		return 0;
 
 	ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
-					 &i2c_dev->fmp_reg);
+					 &i2c_dev->fmp_sreg);
 	if (ret)
 		return ret;
+
+	i2c_dev->fmp_creg = i2c_dev->fmp_sreg +
+			       i2c_dev->setup.fmp_clr_offset;
 
 	return of_property_read_u32_index(np, "st,syscfg-fmp", 2,
 					  &i2c_dev->fmp_mask);
···
 
 static const struct of_device_id stm32f7_i2c_match[] = {
 	{ .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
+	{ .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup},
 	{},
 };
 MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);