[U-Boot] [PATCH v4 14/18] serial: lpuart: add 32-bit registers lpuart support

[Alison Wang]

From: Jingchang Lu <jingchang.lu at freescale.com>

On vybrid, lpuart's registers are 8-bit. On LS102xA, lpuart's registers
are 32-bit. This patch adds the support for 32-bit registers on
LS102xA.

Signed-off-by: Jingchang Lu <jingchang.lu at freescale.com>
Signed-off-by: Yuan Yao <yao.yuan at freescale.com>
---
Change log:
 v4: Add commit messages.
 v3: New file.

 drivers/serial/serial_lpuart.c | 122 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)

diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c
index da5f9a2..6e639b7 100644
--- a/drivers/serial/serial_lpuart.c
+++ b/drivers/serial/serial_lpuart.c
@@ -17,10 +17,34 @@
 #define UC2_TE          (1 << 3)
 #define UC2_RE          (1 << 2)
 
+#define STAT_LBKDIF	(1 << 31)
+#define STAT_RXEDGIF	(1 << 30)
+#define STAT_TDRE	(1 << 23)
+#define STAT_RDRF	(1 << 21)
+#define STAT_IDLE	(1 << 20)
+#define STAT_OR		(1 << 19)
+#define STAT_NF		(1 << 18)
+#define STAT_FE		(1 << 17)
+#define STAT_PF		(1 << 16)
+#define STAT_MA1F	(1 << 15)
+#define STAT_MA2F	(1 << 14)
+#define STAT_FLAGS	(STAT_LBKDIF | STAT_RXEDGIF | STAT_IDLE | STAT_OR | \
+			STAT_NF | STAT_FE | STAT_PF | STAT_MA1F | STAT_MA2F)
+
+#define CTRL_TE		(1 << 19)
+#define CTRL_RE		(1 << 18)
+
+#define FIFO_TXFE		0x80
+#define FIFO_RXFE		0x40
+
+#define WATER_TXWATER_OFF	1
+#define WATER_RXWATER_OFF	16
+
 DECLARE_GLOBAL_DATA_PTR;
 
 struct lpuart_fsl *base = (struct lpuart_fsl *)LPUART_BASE;
 
+#ifndef CONFIG_LPUART_32B_REG
 static void lpuart_serial_setbrg(void)
 {
 	u32 clk = mxc_get_clock(MXC_UART_CLK);
@@ -107,13 +131,111 @@ static struct serial_device lpuart_serial_drv = {
 	.getc = lpuart_serial_getc,
 	.tstc = lpuart_serial_tstc,
 };
+#else
+static void lpuart32_serial_setbrg(void)
+{
+	u32 clk = CONFIG_SYS_CLK_FREQ;
+	u32 sbr;
+
+	if (!gd->baudrate)
+		gd->baudrate = CONFIG_BAUDRATE;
+
+	sbr = (clk / (16 * gd->baudrate));
+	/* place adjustment later - n/32 BRFA */
+
+	out_be32(&base->baud, sbr);
+}
+
+static int lpuart32_serial_getc(void)
+{
+	u32 stat;
+
+	while (((stat = in_be32(&base->stat)) & STAT_RDRF) == 0) {
+		out_be32(&base->stat, STAT_FLAGS);
+		WATCHDOG_RESET();
+	}
+
+	return in_be32(&base->data) & 0x3ff;
+}
+
+static void lpuart32_serial_putc(const char c)
+{
+	if (c == '\n')
+		serial_putc('\r');
+
+	while (!(in_be32(&base->stat) & STAT_TDRE))
+		WATCHDOG_RESET();
+
+	out_be32(&base->data, c);
+}
+
+/*
+ * Test whether a character is in the RX buffer
+ */
+static int lpuart32_serial_tstc(void)
+{
+	if ((in_be32(&base->water) >> 24) == 0)
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Initialise the serial port with the given baudrate. The settings
+ * are always 8 data bits, no parity, 1 stop bit, no start bits.
+ */
+static int lpuart32_serial_init(void)
+{
+	u8 ctrl;
+
+	ctrl = in_be32(&base->ctrl);
+	ctrl &= ~CTRL_RE;
+	ctrl &= ~CTRL_TE;
+	out_be32(&base->ctrl, ctrl);
+
+	out_be32(&base->modir, 0);
+	out_be32(&base->fifo, ~(FIFO_TXFE | FIFO_RXFE));
+
+	out_be32(&base->match, 0);
+	/* provide data bits, parity, stop bit, etc */
+
+	serial_setbrg();
+
+	out_be32(&base->ctrl, CTRL_RE | CTRL_TE);
+
+	return 0;
+}
+
+static struct serial_device lpuart32_serial_drv = {
+	.name = "lpuart32_serial",
+	.start = lpuart32_serial_init,
+	.stop = NULL,
+	.setbrg = lpuart32_serial_setbrg,
+	.putc = lpuart32_serial_putc,
+	.puts = default_serial_puts,
+	.getc = lpuart32_serial_getc,
+	.tstc = lpuart32_serial_tstc,
+};
+#endif
+void lpuart32_serial_initialize(void)
+{
+	serial_register(&lpuart32_serial_drv);
+}
 
 void lpuart_serial_initialize(void)
 {
+#ifdef CONFIG_LPUART_32B_REG
+	serial_register(&lpuart32_serial_drv);
+#else
 	serial_register(&lpuart_serial_drv);
+#endif
 }
 
 __weak struct serial_device *default_serial_console(void)
 {
+#ifdef CONFIG_LPUART_32B_REG
+	return &lpuart32_serial_drv;
+#else
 	return &lpuart_serial_drv;
+#endif
 }
-- 
1.8.4