stm32: Convert serial driver to DM

Signed-off-by: Kamil Lulko <kamil.lulko@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/Kconfig

@@ -697,6 +697,8 @@ config ARCH_UNIPHIER
 config TARGET_STM32F429_DISCOVERY
 	bool "Support STM32F429 Discovery"
 	select CPU_V7M
+	select DM
+	select DM_SERIAL
 
 config ARCH_ROCKCHIP
 	bool "Support Rockchip SoCs"

arch/arm/include/asm/arch-stm32f4/stm32.h

@@ -3,7 +3,7 @@
  * Yuri Tikhonov, Emcraft Systems, yur@emcraft.com
  *
  * (C) Copyright 2015
- * Kamil Lulko, <rev13@wp.pl>
+ * Kamil Lulko, <kamil.lulko@gmail.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -106,6 +106,14 @@ struct stm32_flash_regs {
 #define STM32_FLASH_CR_SNB_OFFSET	3
 #define STM32_FLASH_CR_SNB_MASK		(15 << STM32_FLASH_CR_SNB_OFFSET)
 
+/*
+ * Peripheral base addresses
+ */
+#define STM32_USART1_BASE	(STM32_APB2PERIPH_BASE + 0x1000)
+#define STM32_USART2_BASE	(STM32_APB1PERIPH_BASE + 0x4400)
+#define STM32_USART3_BASE	(STM32_APB1PERIPH_BASE + 0x4800)
+#define STM32_USART6_BASE	(STM32_APB2PERIPH_BASE + 0x1400)
+
 enum clock {
 	CLOCK_CORE,
 	CLOCK_AHB,

board/st/stm32f429-discovery/stm32f429-discovery.c

@@ -6,7 +6,7 @@
  * Pavel Boldin, Emcraft Systems, paboldin@emcraft.com
  *
  * (C) Copyright 2015
- * Kamil Lulko, <rev13@wp.pl>
+ * Kamil Lulko, <kamil.lulko@gmail.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -17,6 +17,8 @@
 #include <asm/arch/stm32.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/fmc.h>
+#include <dm/platdata.h>
+#include <dm/platform_data/serial_stm32.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -263,6 +265,15 @@ int dram_init(void)
 	return rv;
 }
 
+static const struct stm32_serial_platdata serial_platdata = {
+	.base = (struct stm32_usart *)STM32_USART1_BASE,
+};
+
+U_BOOT_DEVICE(stm32_serials) = {
+	.name = "serial_stm32",
+	.platdata = &serial_platdata,
+};
+
 u32 get_board_rev(void)
 {
 	return 0;

doc/driver-model/serial-howto.txt

@@ -18,7 +18,6 @@ is time for maintainers to start converting over the remaining serial drivers:
    serial_pxa.c
    serial_s3c24x0.c
    serial_sa1100.c
-   serial_stm32.c
    serial_xuartlite.c
    usbtty.c
 

drivers/serial/serial_stm32.c

@@ -1,45 +1,18 @@
 /*
  * (C) Copyright 2015
- * Kamil Lulko, <rev13@wp.pl>
+ * Kamil Lulko, <kamil.lulko@gmail.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
+#include <dm.h>
 #include <asm/io.h>
 #include <serial.h>
 #include <asm/arch/stm32.h>
+#include <dm/platform_data/serial_stm32.h>
 
-/*
- * Set up the usart port
- */
-#if (CONFIG_STM32_USART >= 1) && (CONFIG_STM32_USART <= 6)
-#define USART_PORT	(CONFIG_STM32_USART - 1)
-#else
-#define USART_PORT	0
-#endif
-/*
- * Set up the usart base address
- *
- * --STM32_USARTD_BASE means default setting
- */
-#define STM32_USART1_BASE	(STM32_APB2PERIPH_BASE + 0x1000)
-#define STM32_USART2_BASE	(STM32_APB1PERIPH_BASE + 0x4400)
-#define STM32_USART3_BASE	(STM32_APB1PERIPH_BASE + 0x4800)
-#define STM32_USART6_BASE	(STM32_APB2PERIPH_BASE + 0x1400)
-#define STM32_USARTD_BASE	STM32_USART1_BASE
-/*
- * RCC USART specific definitions
- *
- * --RCC_ENR_USARTDEN means default setting
- */
-#define RCC_ENR_USART1EN	(1 << 4)
-#define RCC_ENR_USART2EN	(1 << 17)
-#define RCC_ENR_USART3EN	(1 << 18)
-#define RCC_ENR_USART6EN	(1 <<  5)
-#define RCC_ENR_USARTDEN	RCC_ENR_USART1EN
-
-struct stm32_serial {
+struct stm32_usart {
 	u32 sr;
 	u32 dr;
 	u32 brr;
@@ -49,120 +22,136 @@ struct stm32_serial {
 	u32 gtpr;
 };
 
-#define USART_CR1_RE		(1 << 2)
-#define USART_CR1_TE		(1 << 3)
-#define USART_CR1_UE		(1 << 13)
+#define USART_CR1_RE			(1 << 2)
+#define USART_CR1_TE			(1 << 3)
+#define USART_CR1_UE			(1 << 13)
 
 #define USART_SR_FLAG_RXNE	(1 << 5)
-#define USART_SR_FLAG_TXE	(1 << 7)
+#define USART_SR_FLAG_TXE		(1 << 7)
 
-#define USART_BRR_F_MASK	0xF
+#define USART_BRR_F_MASK		0xF
 #define USART_BRR_M_SHIFT	4
 #define USART_BRR_M_MASK	0xFFF0
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static const unsigned long usart_base[] = {
-	STM32_USART1_BASE,
-	STM32_USART2_BASE,
-	STM32_USART3_BASE,
-	STM32_USARTD_BASE,
-	STM32_USARTD_BASE,
-	STM32_USART6_BASE
-};
+#define MAX_SERIAL_PORTS		4
 
-static const unsigned long rcc_enr_en[] = {
-	RCC_ENR_USART1EN,
-	RCC_ENR_USART2EN,
-	RCC_ENR_USART3EN,
-	RCC_ENR_USARTDEN,
-	RCC_ENR_USARTDEN,
-	RCC_ENR_USART6EN
+/*
+ * RCC USART specific definitions
+ */
+#define RCC_ENR_USART1EN		(1 << 4)
+#define RCC_ENR_USART2EN		(1 << 17)
+#define RCC_ENR_USART3EN		(1 << 18)
+#define RCC_ENR_USART6EN		(1 <<  5)
+
+/* Array used to figure out which RCC bit needs to be set */
+static const unsigned long usart_port_rcc_pairs[MAX_SERIAL_PORTS][2] = {
+	{ STM32_USART1_BASE, RCC_ENR_USART1EN },
+	{ STM32_USART2_BASE, RCC_ENR_USART2EN },
+	{ STM32_USART3_BASE, RCC_ENR_USART3EN },
+	{ STM32_USART6_BASE, RCC_ENR_USART6EN }
 };
 
-static void stm32_serial_setbrg(void)
+static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
 {
-	serial_init();
-}
+	struct stm32_serial_platdata *plat = dev->platdata;
+	struct stm32_usart *const usart = plat->base;
+	u32  clock, int_div, frac_div, tmp;
 
-static int stm32_serial_init(void)
-{
-	struct stm32_serial *usart =
-		(struct stm32_serial *)usart_base[USART_PORT];
-	u32 clock, int_div, frac_div, tmp;
-
-	if ((usart_base[USART_PORT] & STM32_BUS_MASK) ==
-			STM32_APB1PERIPH_BASE) {
-		setbits_le32(&STM32_RCC->apb1enr, rcc_enr_en[USART_PORT]);
+	if (((u32)usart & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE)
 		clock = clock_get(CLOCK_APB1);
-	} else if ((usart_base[USART_PORT] & STM32_BUS_MASK) ==
-			STM32_APB2PERIPH_BASE) {
-		setbits_le32(&STM32_RCC->apb2enr, rcc_enr_en[USART_PORT]);
+	else if (((u32)usart & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE)
 		clock = clock_get(CLOCK_APB2);
-	} else {
-		return -1;
-	}
+	else
+		return -EINVAL;
 
-	int_div = (25 * clock) / (4 * gd->baudrate);
+	int_div = (25 * clock) / (4 * baudrate);
 	tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK;
 	frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT));
 	tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK;
-
 	writel(tmp, &usart->brr);
-	setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
 
 	return 0;
 }
 
-static int stm32_serial_getc(void)
+static int stm32_serial_getc(struct udevice *dev)
 {
-	struct stm32_serial *usart =
-		(struct stm32_serial *)usart_base[USART_PORT];
-	while ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
-		;
+	struct stm32_serial_platdata *plat = dev->platdata;
+	struct stm32_usart *const usart = plat->base;
+
+	if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
+		return -EAGAIN;
+
 	return readl(&usart->dr);
 }
 
-static void stm32_serial_putc(const char c)
+static int stm32_serial_putc(struct udevice *dev, const char c)
 {
-	struct stm32_serial *usart =
-		(struct stm32_serial *)usart_base[USART_PORT];
+	struct stm32_serial_platdata *plat = dev->platdata;
+	struct stm32_usart *const usart = plat->base;
 
-	if (c == '\n')
-		stm32_serial_putc('\r');
+	if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
+		return -EAGAIN;
 
-	while ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
-		;
 	writel(c, &usart->dr);
+
+	return 0;
 }
 
-static int stm32_serial_tstc(void)
+static int stm32_serial_pending(struct udevice *dev, bool input)
 {
-	struct stm32_serial *usart =
-		(struct stm32_serial *)usart_base[USART_PORT];
-	u8 ret;
+	struct stm32_serial_platdata *plat = dev->platdata;
+	struct stm32_usart *const usart = plat->base;
 
-	ret = readl(&usart->sr) & USART_SR_FLAG_RXNE;
-	return ret;
+	if (input)
+		return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
+	else
+		return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
 }
 
-static struct serial_device stm32_serial_drv = {
-	.name	= "stm32_serial",
-	.start	= stm32_serial_init,
-	.stop	= NULL,
-	.setbrg	= stm32_serial_setbrg,
-	.putc	= stm32_serial_putc,
-	.puts	= default_serial_puts,
-	.getc	= stm32_serial_getc,
-	.tstc	= stm32_serial_tstc,
-};
-
-void stm32_serial_initialize(void)
+static int stm32_serial_probe(struct udevice *dev)
 {
-	serial_register(&stm32_serial_drv);
-}
+	struct stm32_serial_platdata *plat = dev->platdata;
+	struct stm32_usart *const usart = plat->base;
+	int usart_port = -1;
+	int i;
+
+	for (i = 0; i < MAX_SERIAL_PORTS; i++) {
+		if ((u32)usart == usart_port_rcc_pairs[i][0]) {
+			usart_port = i;
+			break;
+		}
+	}
 
-__weak struct serial_device *default_serial_console(void)
-{
-	return &stm32_serial_drv;
+	if (usart_port == -1)
+		return -EINVAL;
+
+	if (((u32)usart & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE)
+		setbits_le32(&STM32_RCC->apb1enr,
+			     usart_port_rcc_pairs[usart_port][1]);
+	else if (((u32)usart & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE)
+		setbits_le32(&STM32_RCC->apb2enr,
+			     usart_port_rcc_pairs[usart_port][1]);
+	else
+		return -EINVAL;
+
+	setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
+
+	return 0;
 }
+
+static const struct dm_serial_ops stm32_serial_ops = {
+	.putc = stm32_serial_putc,
+	.pending = stm32_serial_pending,
+	.getc = stm32_serial_getc,
+	.setbrg = stm32_serial_setbrg,
+};
+
+U_BOOT_DRIVER(serial_stm32) = {
+	.name = "serial_stm32",
+	.id = UCLASS_SERIAL,
+	.ops = &stm32_serial_ops,
+	.probe = stm32_serial_probe,
+	.flags = DM_FLAG_PRE_RELOC,
+};

include/configs/stm32f429-discovery.h

@@ -1,6 +1,6 @@
 /*
  * (C) Copyright 2015
- * Kamil Lulko, <rev13@wp.pl>
+ * Kamil Lulko, <kamil.lulko@gmail.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -51,14 +51,6 @@
 
 #define CONFIG_STM32_GPIO
 #define CONFIG_STM32_SERIAL
-/*
- * Configuration of the USART
- * 1:   TX:PA9  RX:PA10
- * 2:   TX:PD5  RX:PD6
- * 3:   TX:PC10 RX:PC11
- * 6:   TX:PG14 RX:PG9
- */
-#define CONFIG_STM32_USART		1
 
 #define CONFIG_STM32_HSE_HZ		8000000
 

include/dm/platform_data/serial_stm32.h

@@ -0,0 +1,16 @@
+/*
+ * (C) Copyright 2015
+ * Kamil Lulko, <kamil.lulko@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __SERIAL_STM32_H
+#define __SERIAL_STM32_H
+
+/* Information about a serial port */
+struct stm32_serial_platdata {
+	struct stm32_usart *base;  /* address of registers in physical memory */
+};
+
+#endif /* __SERIAL_STM32_H */