serial: sc16is7xx: split into core and I2C/SPI parts (sc16is7xx_regcfg)

Since each I2C/SPI probe function can modify sc16is7xx_regcfg at the same
time, change structure to be constant and do the required modifications on
a local copy.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240409154253.3043822-6-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sc16is7xx.c

@@ -1695,7 +1695,7 @@ const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
 EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
 
-struct regmap_config sc16is7xx_regcfg = {
+const struct regmap_config sc16is7xx_regcfg = {
 	.reg_bits = 5,
 	.pad_bits = 3,
 	.val_bits = 8,

drivers/tty/serial/sc16is7xx.h

@@ -19,7 +19,7 @@ struct sc16is7xx_devtype {
 	int	nr_uart;
 };
 
-extern struct regmap_config sc16is7xx_regcfg;
+extern const struct regmap_config sc16is7xx_regcfg;
 
 extern const struct of_device_id sc16is7xx_dt_ids[];
 

drivers/tty/serial/sc16is7xx_i2c.c

@@ -14,17 +14,20 @@ static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
 {
 	const struct sc16is7xx_devtype *devtype;
 	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
+	struct regmap_config regcfg;
 	unsigned int i;
 
 	devtype = i2c_get_match_data(i2c);
 	if (!devtype)
 		return dev_err_probe(&i2c->dev, -ENODEV, "Failed to match device\n");
 
+	memcpy(&regcfg, &sc16is7xx_regcfg, sizeof(struct regmap_config));
+
 	for (i = 0; i < devtype->nr_uart; i++) {
-		sc16is7xx_regcfg.name = sc16is7xx_regmap_name(i);
-		sc16is7xx_regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
-		sc16is7xx_regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_i2c(i2c, &sc16is7xx_regcfg);
+		regcfg.name = sc16is7xx_regmap_name(i);
+		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_i2c(i2c, &regcfg);
 	}
 
 	return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);

drivers/tty/serial/sc16is7xx_spi.c

@@ -18,6 +18,7 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 {
 	const struct sc16is7xx_devtype *devtype;
 	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
+	struct regmap_config regcfg;
 	unsigned int i;
 	int ret;
 
@@ -37,17 +38,19 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 	if (!devtype)
 		return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
 
+	memcpy(&regcfg, &sc16is7xx_regcfg, sizeof(struct regmap_config));
+
 	for (i = 0; i < devtype->nr_uart; i++) {
-		sc16is7xx_regcfg.name = sc16is7xx_regmap_name(i);
+		regcfg.name = sc16is7xx_regmap_name(i);
 		/*
 		 * If read_flag_mask is 0, the regmap code sets it to a default
 		 * of 0x80. Since we specify our own mask, we must add the READ
 		 * bit ourselves:
 		 */
-		sc16is7xx_regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
+		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
 			SC16IS7XX_SPI_READ_BIT;
-		sc16is7xx_regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_spi(spi, &sc16is7xx_regcfg);
+		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
 	}
 
 	return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);