i2c: designware: Remove not-going-to-be-supported code for Baikal SoC

As noticed in the discussion [1] the Baikal SoC and platforms
are not going to be finalized, hence remove stale code.

Link: https://lore.kernel.org/lkml/22b92ddf-6321-41b5-8073-f9c7064d3432@infradead.org/ [1]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260114081954.252160-2-andriy.shevchenko@linux.intel.com

Author: andy-shev

drivers/i2c/busses/Kconfig

@@ -579,7 +579,6 @@ if I2C_DESIGNWARE_CORE
 config I2C_DESIGNWARE_PLATFORM
 	tristate "Synopsys DesignWare Platform driver"
 	depends on (ACPI && COMMON_CLK) || !ACPI
-	select MFD_SYSCON if MIPS_BAIKAL_T1
 	default I2C_DESIGNWARE_CORE
 	help
 	  If you say yes to this option, support will be included for the

drivers/i2c/busses/i2c-designware-core.h

@@ -314,7 +314,6 @@ struct dw_i2c_dev {
 #define ACCESS_POLLING				BIT(3)
 
 #define MODEL_MSCC_OCELOT			BIT(8)
-#define MODEL_BAIKAL_BT1			BIT(9)
 #define MODEL_AMD_NAVI_GPU			BIT(10)
 #define MODEL_WANGXUN_SP			BIT(11)
 #define MODEL_MASK				GENMASK(11, 8)

drivers/i2c/busses/i2c-designware-platdrv.c

@@ -37,70 +37,6 @@ static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 	return clk_get_rate(dev->clk) / HZ_PER_KHZ;
 }
 
-#ifdef CONFIG_OF
-#define BT1_I2C_CTL			0x100
-#define BT1_I2C_CTL_ADDR_MASK		GENMASK(7, 0)
-#define BT1_I2C_CTL_WR			BIT(8)
-#define BT1_I2C_CTL_GO			BIT(31)
-#define BT1_I2C_DI			0x104
-#define BT1_I2C_DO			0x108
-
-static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
-{
-	struct dw_i2c_dev *dev = context;
-	int ret;
-
-	/*
-	 * Note these methods shouldn't ever fail because the system controller
-	 * registers are memory mapped. We check the return value just in case.
-	 */
-	ret = regmap_write(dev->sysmap, BT1_I2C_CTL,
-			   BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
-	if (ret)
-		return ret;
-
-	return regmap_read(dev->sysmap, BT1_I2C_DO, val);
-}
-
-static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
-{
-	struct dw_i2c_dev *dev = context;
-	int ret;
-
-	ret = regmap_write(dev->sysmap, BT1_I2C_DI, val);
-	if (ret)
-		return ret;
-
-	return regmap_write(dev->sysmap, BT1_I2C_CTL,
-			    BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
-}
-
-static const struct regmap_config bt1_i2c_cfg = {
-	.reg_bits = 32,
-	.val_bits = 32,
-	.reg_stride = 4,
-	.fast_io = true,
-	.reg_read = bt1_i2c_read,
-	.reg_write = bt1_i2c_write,
-	.max_register = DW_IC_COMP_TYPE,
-};
-
-static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
-{
-	dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent);
-	if (IS_ERR(dev->sysmap))
-		return PTR_ERR(dev->sysmap);
-
-	dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg);
-	return PTR_ERR_OR_ZERO(dev->map);
-}
-#else
-static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
-{
-	return -ENODEV;
-}
-#endif
-
 static int dw_i2c_get_parent_regmap(struct dw_i2c_dev *dev)
 {
 	dev->map = dev_get_regmap(dev->dev->parent, NULL);
@@ -127,9 +63,6 @@ static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
 		return dw_i2c_get_parent_regmap(dev);
 
 	switch (dev->flags & MODEL_MASK) {
-	case MODEL_BAIKAL_BT1:
-		ret = bt1_i2c_request_regs(dev);
-		break;
 	case MODEL_WANGXUN_SP:
 		ret = dw_i2c_get_parent_regmap(dev);
 		break;
@@ -334,7 +267,6 @@ static void dw_i2c_plat_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id dw_i2c_of_match[] = {
-	{ .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
 	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
 	{ .compatible = "snps,designware-i2c" },
 	{}