serial: uniphier: use register macros instead of structure

After all, I am not a big fan of using a structure to represent the
hardware register map.

You do not need to know the entire register map.

Add only necessary register macros.

Use FIELD_PREP() instead of maintaining a pair of shift and mask.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

drivers/serial/serial_uniphier.c

@@ -7,6 +7,8 @@
 
 #include <common.h>
 #include <dm.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/io.h>
 #include <linux/serial_reg.h>
@@ -15,77 +17,67 @@
 #include <serial.h>
 #include <fdtdec.h>
 
-/*
- * Note: Register map is slightly different from that of 16550.
- */
-struct uniphier_serial {
-	u32 rx;			/* In:  Receive buffer */
-#define tx rx			/* Out: Transmit buffer */
-	u32 ier;		/* Interrupt Enable Register */
-	u32 iir;		/* In: Interrupt ID Register */
-	u32 char_fcr;		/* Charactor / FIFO Control Register */
-	u32 lcr_mcr;		/* Line/Modem Control Register */
-#define LCR_SHIFT	8
-#define LCR_MASK	(0xff << (LCR_SHIFT))
-	u32 lsr;		/* In: Line Status Register */
-	u32 msr;		/* In: Modem Status Register */
-	u32 __rsv0;
-	u32 __rsv1;
-	u32 dlr;		/* Divisor Latch Register */
-};
+#define UNIPHIER_UART_REGSHIFT		2
+
+#define UNIPHIER_UART_RX		(0 << (UNIPHIER_UART_REGSHIFT))
+#define UNIPHIER_UART_TX		UNIPHIER_UART_RX
+/* bit[15:8] = CHAR, bit[7:0] = FCR */
+#define UNIPHIER_UART_CHAR_FCR		(3 << (UNIPHIER_UART_REGSHIFT))
+/* bit[15:8] = LCR, bit[7:0] = MCR */
+#define UNIPHIER_UART_LCR_MCR		(4 << (UNIPHIER_UART_REGSHIFT))
+#define   UNIPHIER_UART_LCR_MASK		GENMASK(15, 8)
+#define UNIPHIER_UART_LSR		(5 << (UNIPHIER_UART_REGSHIFT))
+/* Divisor Latch Register */
+#define UNIPHIER_UART_DLR		(9 << (UNIPHIER_UART_REGSHIFT))
 
 struct uniphier_serial_priv {
-	struct uniphier_serial __iomem *membase;
+	void __iomem *membase;
 	unsigned int uartclk;
 };
 
-#define uniphier_serial_port(dev)	\
-	((struct uniphier_serial_priv *)dev_get_priv(dev))->membase
-
 static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
 {
 	struct uniphier_serial_priv *priv = dev_get_priv(dev);
-	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
-	const unsigned int mode_x_div = 16;
+	static const unsigned int mode_x_div = 16;
 	unsigned int divisor;
 
 	divisor = DIV_ROUND_CLOSEST(priv->uartclk, mode_x_div * baudrate);
 
-	writel(divisor, &port->dlr);
+	writel(divisor, priv->membase + UNIPHIER_UART_DLR);
 
 	return 0;
 }
 
 static int uniphier_serial_getc(struct udevice *dev)
 {
-	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
+	struct uniphier_serial_priv *priv = dev_get_priv(dev);
 
-	if (!(readl(&port->lsr) & UART_LSR_DR))
+	if (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_DR))
 		return -EAGAIN;
 
-	return readl(&port->rx);
+	return readl(priv->membase + UNIPHIER_UART_RX);
 }
 
 static int uniphier_serial_putc(struct udevice *dev, const char c)
 {
-	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
+	struct uniphier_serial_priv *priv = dev_get_priv(dev);
 
-	if (!(readl(&port->lsr) & UART_LSR_THRE))
+	if (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_THRE))
 		return -EAGAIN;
 
-	writel(c, &port->tx);
+	writel(c, priv->membase + UNIPHIER_UART_TX);
 
 	return 0;
 }
 
 static int uniphier_serial_pending(struct udevice *dev, bool input)
 {
-	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
+	struct uniphier_serial_priv *priv = dev_get_priv(dev);
 
 	if (input)
-		return readl(&port->lsr) & UART_LSR_DR;
+		return readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_DR;
 	else
-		return !(readl(&port->lsr) & UART_LSR_THRE);
+		return !(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_THRE);
 }
 
 /*
@@ -113,7 +105,6 @@ static const struct uniphier_serial_clk_data uniphier_serial_clk_data[] = {
 static int uniphier_serial_probe(struct udevice *dev)
 {
 	struct uniphier_serial_priv *priv = dev_get_priv(dev);
-	struct uniphier_serial __iomem *port;
 	const struct uniphier_serial_clk_data *clk_data;
 	ofnode root_node;
 	fdt_addr_t base;
@@ -123,12 +114,10 @@ static int uniphier_serial_probe(struct udevice *dev)
 	if (base == FDT_ADDR_T_NONE)
 		return -EINVAL;
 
-	port = devm_ioremap(dev, base, SZ_64);
-	if (!port)
+	priv->membase = devm_ioremap(dev, base, SZ_64);
+	if (!priv->membase)
 		return -ENOMEM;
 
-	priv->membase = port;
-
 	root_node = ofnode_path("/");
 	clk_data = uniphier_serial_clk_data;
 	while (clk_data->compatible) {
@@ -143,10 +132,10 @@ static int uniphier_serial_probe(struct udevice *dev)
 
 	priv->uartclk = clk_data->clk_rate;
 
-	tmp = readl(&port->lcr_mcr);
-	tmp &= ~LCR_MASK;
-	tmp |= UART_LCR_WLEN8 << LCR_SHIFT;
-	writel(tmp, &port->lcr_mcr);
+	tmp = readl(priv->membase + UNIPHIER_UART_LCR_MCR);
+	tmp &= ~UNIPHIER_UART_LCR_MASK;
+	tmp |= FIELD_PREP(UNIPHIER_UART_LCR_MASK, UART_LCR_WLEN8);
+	writel(tmp, priv->membase + UNIPHIER_UART_LCR_MCR);
 
 	return 0;
 }