nios2: convert altera_uart to driver model

Convert altera_uart to driver model.
Signed-off-by: NThomas Chou <thomas@wytron.com.tw>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Acked-by: NMarek Vasut <marex@denx.de>

doc/device-tree-bindings/serial/altera_uart.txt

+Altera UART
+
+Required properties:
+- compatible : should be "altr,uart-1.0"
+
+Optional properties:
+- clock-frequency : frequency of the clock input to the UART

drivers/serial/Kconfig

@@ -61,6 +61,13 @@ config DEBUG_UART_ALTERA_JTAGUART
 	  You will need to provide parameters to make this work. The driver will
 	  be available until the real driver model serial is running.
 
+config DEBUG_UART_ALTERA_UART
+	bool "Altera UART"
+	help
+	  Select this to enable a debug UART using the altera_uart driver.
+	  You will need to provide parameters to make this work. The driver will
+	  be available until the real driver model serial is running.
+
 config DEBUG_UART_NS16550
 	bool "ns16550"
 	help
@@ -156,6 +163,13 @@ config ALTERA_JTAG_UART_BYPASS
 	  output will wait forever until a JTAG terminal is connected. If you
 	  not are sure, say Y.
 
+config ALTERA_UART
+	bool "Altera UART support"
+	depends on DM_SERIAL
+	help
+	  Select this to enable an UART for Altera devices. Please find
+	  details on the "Embedded Peripherals IP User Guide" of Altera.
+
 config ROCKCHIP_SERIAL
 	bool "Rockchip on-chip UART support"
 	depends on ARCH_ROCKCHIP && DM_SERIAL

drivers/serial/altera_uart.c

@@ -5,133 +5,149 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-
 #include <common.h>
-#include <watchdog.h>
+#include <dm.h>
+#include <errno.h>
 #include <asm/io.h>
 #include <linux/compiler.h>
 #include <serial.h>
 
-typedef volatile struct {
-	unsigned	rxdata;		/* Rx data reg */
-	unsigned	txdata;		/* Tx data reg */
-	unsigned	status;		/* Status reg */
-	unsigned	control;	/* Control reg */
-	unsigned	divisor;	/* Baud rate divisor reg */
-	unsigned	endofpacket;	/* End-of-packet reg */
-} nios_uart_t;
+struct altera_uart_regs {
+	u32	rxdata;		/* Rx data reg */
+	u32	txdata;		/* Tx data reg */
+	u32	status;		/* Status reg */
+	u32	control;	/* Control reg */
+	u32	divisor;	/* Baud rate divisor reg */
+	u32	endofpacket;	/* End-of-packet reg */
+};
+
+struct altera_uart_platdata {
+	struct altera_uart_regs *regs;
+	unsigned int uartclk;
+};
 
 /* status register */
-#define NIOS_UART_PE		(1 << 0)	/* parity error */
-#define NIOS_UART_FE		(1 << 1)	/* frame error */
-#define NIOS_UART_BRK		(1 << 2)	/* break detect */
-#define NIOS_UART_ROE		(1 << 3)	/* rx overrun */
-#define NIOS_UART_TOE		(1 << 4)	/* tx overrun */
-#define NIOS_UART_TMT		(1 << 5)	/* tx empty */
-#define NIOS_UART_TRDY		(1 << 6)	/* tx ready */
-#define NIOS_UART_RRDY		(1 << 7)	/* rx ready */
-#define NIOS_UART_E		(1 << 8)	/* exception */
-#define NIOS_UART_DCTS		(1 << 10)	/* cts change */
-#define NIOS_UART_CTS		(1 << 11)	/* cts */
-#define NIOS_UART_EOP		(1 << 12)	/* eop detected */
-
-/* control register */
-#define NIOS_UART_IPE		(1 << 0)	/* parity error int ena*/
-#define NIOS_UART_IFE		(1 << 1)	/* frame error int ena */
-#define NIOS_UART_IBRK		(1 << 2)	/* break detect int ena */
-#define NIOS_UART_IROE		(1 << 3)	/* rx overrun int ena */
-#define NIOS_UART_ITOE		(1 << 4)	/* tx overrun int ena */
-#define NIOS_UART_ITMT		(1 << 5)	/* tx empty int ena */
-#define NIOS_UART_ITRDY		(1 << 6)	/* tx ready int ena */
-#define NIOS_UART_IRRDY		(1 << 7)	/* rx ready int ena */
-#define NIOS_UART_IE		(1 << 8)	/* exception int ena */
-#define NIOS_UART_TBRK		(1 << 9)	/* transmit break */
-#define NIOS_UART_IDCTS		(1 << 10)	/* cts change int ena */
-#define NIOS_UART_RTS		(1 << 11)	/* rts */
-#define NIOS_UART_IEOP		(1 << 12)	/* eop detected int ena */
+#define ALTERA_UART_TMT		(1 << 5)	/* tx empty */
+#define ALTERA_UART_TRDY	(1 << 6)	/* tx ready */
+#define ALTERA_UART_RRDY	(1 << 7)	/* rx ready */
 
 DECLARE_GLOBAL_DATA_PTR;
 
-/*------------------------------------------------------------------
- * UART the serial port
- *-----------------------------------------------------------------*/
-
-static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
+static int altera_uart_setbrg(struct udevice *dev, int baudrate)
+{
+	struct altera_uart_platdata *plat = dev->platdata;
+	struct altera_uart_regs *const regs = plat->regs;
+	u32 div;
 
-#if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
+	div = (plat->uartclk / baudrate) - 1;
+	writel(div, &regs->divisor);
 
-/*
- * Everything's already setup for fixed-baud PTF
- * assignment
- */
-static void altera_serial_setbrg(void)
-{
+	return 0;
 }
 
-static int altera_serial_init(void)
+static int altera_uart_putc(struct udevice *dev, const char ch)
 {
-	return 0;
-}
+	struct altera_uart_platdata *plat = dev->platdata;
+	struct altera_uart_regs *const regs = plat->regs;
 
-#else
+	if (!(readl(&regs->status) & ALTERA_UART_TRDY))
+		return -EAGAIN;
 
-static void altera_serial_setbrg(void)
-{
-	unsigned div;
+	writel(ch, &regs->txdata);
 
-	div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
-	writel (div, &uart->divisor);
+	return 0;
 }
 
-static int altera_serial_init(void)
+static int altera_uart_pending(struct udevice *dev, bool input)
 {
-	serial_setbrg();
-	return 0;
+	struct altera_uart_platdata *plat = dev->platdata;
+	struct altera_uart_regs *const regs = plat->regs;
+	u32 st = readl(&regs->status);
+
+	if (input)
+		return st & ALTERA_UART_RRDY ? 1 : 0;
+	else
+		return !(st & ALTERA_UART_TMT);
 }
 
-#endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
-
-/*-----------------------------------------------------------------------
- * UART CONSOLE
- *---------------------------------------------------------------------*/
-static void altera_serial_putc(char c)
+static int altera_uart_getc(struct udevice *dev)
 {
-	if (c == '\n')
-		serial_putc ('\r');
-	while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
-		WATCHDOG_RESET ();
-	writel ((unsigned char)c, &uart->txdata);
+	struct altera_uart_platdata *plat = dev->platdata;
+	struct altera_uart_regs *const regs = plat->regs;
+
+	if (!(readl(&regs->status) & ALTERA_UART_RRDY))
+		return -EAGAIN;
+
+	return readl(&regs->rxdata) & 0xff;
 }
 
-static int altera_serial_tstc(void)
+static int altera_uart_probe(struct udevice *dev)
 {
-	return (readl (&uart->status) & NIOS_UART_RRDY);
+	return 0;
 }
 
-static int altera_serial_getc(void)
+static int altera_uart_ofdata_to_platdata(struct udevice *dev)
 {
-	while (serial_tstc () == 0)
-		WATCHDOG_RESET ();
-	return (readl (&uart->rxdata) & 0x00ff );
+	struct altera_uart_platdata *plat = dev_get_platdata(dev);
+
+	plat->regs = ioremap(dev_get_addr(dev),
+		sizeof(struct altera_uart_regs));
+	plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+		"clock-frequency", 0);
+
+	return 0;
 }
 
-static struct serial_device altera_serial_drv = {
-	.name	= "altera_serial",
-	.start	= altera_serial_init,
-	.stop	= NULL,
-	.setbrg	= altera_serial_setbrg,
-	.putc	= altera_serial_putc,
-	.puts	= default_serial_puts,
-	.getc	= altera_serial_getc,
-	.tstc	= altera_serial_tstc,
+static const struct dm_serial_ops altera_uart_ops = {
+	.putc = altera_uart_putc,
+	.pending = altera_uart_pending,
+	.getc = altera_uart_getc,
+	.setbrg = altera_uart_setbrg,
+};
+
+static const struct udevice_id altera_uart_ids[] = {
+	{ .compatible = "altr,uart-1.0", },
+	{ }
+};
+
+U_BOOT_DRIVER(altera_uart) = {
+	.name	= "altera_uart",
+	.id	= UCLASS_SERIAL,
+	.of_match = altera_uart_ids,
+	.ofdata_to_platdata = altera_uart_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct altera_uart_platdata),
+	.probe = altera_uart_probe,
+	.ops	= &altera_uart_ops,
+	.flags = DM_FLAG_PRE_RELOC,
 };
 
-void altera_serial_initialize(void)
+#ifdef CONFIG_DEBUG_UART_ALTERA_UART
+
+#include <debug_uart.h>
+
+void debug_uart_init(void)
 {
-	serial_register(&altera_serial_drv);
+	struct altera_uart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
+	u32 div;
+
+	div = (CONFIG_DEBUG_UART_CLOCK / CONFIG_BAUDRATE) - 1;
+	writel(div, &regs->divisor);
 }
 
-__weak struct serial_device *default_serial_console(void)
+static inline void _debug_uart_putc(int ch)
 {
-	return &altera_serial_drv;
+	struct altera_uart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
+
+	while (1) {
+		u32 st = readl(&regs->status);
+
+		if (st & ALTERA_UART_TRDY)
+			break;
+	}
+
+	writel(ch, &regs->txdata);
 }
+
+DEBUG_UART_FUNCS
+
+#endif

include/configs/nios2-generic.h

@@ -23,14 +23,7 @@
 /*
  * SERIAL
  */
-#if defined(CONFIG_ALTERA_JTAG_UART)
-#else
-# define CONFIG_SYS_NIOS_CONSOLE	CONFIG_SYS_UART_BASE
-#endif
-
-#define CONFIG_SYS_NIOS_FIXEDBAUD
-#define CONFIG_BAUDRATE		CONFIG_SYS_UART_BAUD
-#define CONFIG_SYS_BAUDRATE_TABLE	{CONFIG_BAUDRATE}
+#define CONFIG_BAUDRATE			115200
 #define CONFIG_SYS_CONSOLE_INFO_QUIET	/* Suppress console info */
 
 /*