serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw

The container of the struct dw8250_port_data is private to the actual
driver. In particular, 8250_lpss and 8250_dw use different data types
that are assigned to the UART port private_data. Hence, it must not
be used outside the specific driver.

Currently the only cpr_val is required by the common code, make it
be available via struct dw8250_port_data.

This fixes the UART breakage on Intel Galileo boards.

Fixes: 593dea0 ("serial: 8250: dw: Allow to use a fallback CPR value if not synthesized")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240514190730.2787071-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_dw.c

@@ -55,6 +55,7 @@
 #define DW_UART_QUIRK_SKIP_SET_RATE	BIT(2)
 #define DW_UART_QUIRK_IS_DMA_FC		BIT(3)
 #define DW_UART_QUIRK_APMC0D08		BIT(4)
+#define DW_UART_QUIRK_CPR_VALUE		BIT(5)
 
 static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
 {
@@ -432,6 +433,10 @@ static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 {
 	unsigned int quirks = data->pdata ? data->pdata->quirks : 0;
+	u32 cpr_value = data->pdata ? data->pdata->cpr_value : 0;
+
+	if (quirks & DW_UART_QUIRK_CPR_VALUE)
+		data->data.cpr_value = cpr_value;
 
 #ifdef CONFIG_64BIT
 	if (quirks & DW_UART_QUIRK_OCTEON) {
@@ -714,8 +719,8 @@ static const struct dw8250_platform_data dw8250_armada_38x_data = {
 
 static const struct dw8250_platform_data dw8250_renesas_rzn1_data = {
 	.usr_reg = DW_UART_USR,
-	.cpr_val = 0x00012f32,
-	.quirks = DW_UART_QUIRK_IS_DMA_FC,
+	.cpr_value = 0x00012f32,
+	.quirks = DW_UART_QUIRK_CPR_VALUE | DW_UART_QUIRK_IS_DMA_FC,
 };
 
 static const struct dw8250_platform_data dw8250_starfive_jh7100_data = {

drivers/tty/serial/8250/8250_dwlib.c

@@ -242,7 +242,6 @@ static const struct serial_rs485 dw8250_rs485_supported = {
 void dw8250_setup_port(struct uart_port *p)
 {
 	struct dw8250_port_data *pd = p->private_data;
-	struct dw8250_data *data = to_dw8250_data(pd);
 	struct uart_8250_port *up = up_to_u8250p(p);
 	u32 reg, old_dlf;
 
@@ -278,7 +277,7 @@ void dw8250_setup_port(struct uart_port *p)
 
 	reg = dw8250_readl_ext(p, DW_UART_CPR);
 	if (!reg) {
-		reg = data->pdata->cpr_val;
+		reg = pd->cpr_value;
 		dev_dbg(p->dev, "CPR is not available, using 0x%08x instead\n", reg);
 	}
 	if (!reg)

drivers/tty/serial/8250/8250_dwlib.h

@@ -19,6 +19,7 @@ struct dw8250_port_data {
 	struct uart_8250_dma	dma;
 
 	/* Hardware configuration */
+	u32			cpr_value;
 	u8			dlf_size;
 
 	/* RS485 variables */
@@ -27,7 +28,7 @@ struct dw8250_port_data {
 
 struct dw8250_platform_data {
 	u8 usr_reg;
-	u32 cpr_val;
+	u32 cpr_value;
 	unsigned int quirks;
 };