2016-01-04 15:00 GMT+01:00 Purna Chandra Mandal purna.mandal@microchip.com:
Signed-off-by: Paul Thacker paul.thacker@microchip.com Signed-off-by: Purna Chandra Mandal purna.mandal@microchip.com
Changes in v2:
- fix missing or corrupted chars during baud rate change
- remove loop until any new char is available in _getc()
.../serial/microchip,pic32-uart.txt | 5 + drivers/serial/Kconfig | 13 ++ drivers/serial/Makefile | 1 + drivers/serial/serial_pic32.c | 230 +++++++++++++++++++++ 4 files changed, 249 insertions(+) create mode 100644 doc/device-tree-bindings/serial/microchip,pic32-uart.txt create mode 100644 drivers/serial/serial_pic32.c
diff --git a/doc/device-tree-bindings/serial/microchip,pic32-uart.txt b/doc/device-tree-bindings/serial/microchip,pic32-uart.txt new file mode 100644 index 0000000..f00e215 --- /dev/null +++ b/doc/device-tree-bindings/serial/microchip,pic32-uart.txt @@ -0,0 +1,5 @@ +* Microchip PIC32 serial UART
+Required properties: +- compatible: must be "microchip,pic32mzda-uart". +- reg: exactly one register range. diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 1fc287e..9763ea1 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -107,6 +107,14 @@ config DEBUG_UART_APBUART 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_PIC32
bool "Microchip PIC32"helpSelect this to enable a debug UART using the serial_pic32 driver. Youwill need to provide parameters to make this work. The driver willbe available until the real driver model serial is running.endchoice
config DEBUG_UART_BASE @@ -223,4 +231,9 @@ config UNIPHIER_SERIAL If you have a UniPhier based board and want to use the on-chip serial ports, say Y to this option. If unsure, say N.
+config PIC32_SERIAL
bool "Support for Microchip PIC32 on-chip UART"helpSupport for the UART found on Microchip PIC32 SoC's.endmenu diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index dd87147..57cd38b 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_MXS_AUART) += mxs_auart.o obj-$(CONFIG_ARC_SERIAL) += serial_arc.o obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o +obj-$(CONFIG_PIC32_SERIAL) += serial_pic32.o
ifndef CONFIG_SPL_BUILD obj-$(CONFIG_USB_TTY) += usbtty.o diff --git a/drivers/serial/serial_pic32.c b/drivers/serial/serial_pic32.c new file mode 100644 index 0000000..3eddb57 --- /dev/null +++ b/drivers/serial/serial_pic32.c @@ -0,0 +1,230 @@ +/*
- (c) 2015 Paul Thacker paul.thacker@microchip.com
- SPDX-License-Identifier: GPL-2.0+
- */
+#include <common.h> +#include <config.h> +#include <dm.h> +#include <clk.h> +#include <serial.h> +#include <wait_bit.h> +#include <mach/pic32.h> +#include <dt-bindings/clock/microchip,clock.h>
+DECLARE_GLOBAL_DATA_PTR;
+/* UART Control Registers */ +#define U_MOD 0x00 +#define U_MODCLR (U_MOD + _CLR_OFFSET) +#define U_MODSET (U_MOD + _SET_OFFSET) +#define U_STA 0x10 +#define U_STACLR (U_STA + _CLR_OFFSET) +#define U_STASET (U_STA + _SET_OFFSET) +#define U_TXR 0x20 +#define U_RXR 0x30 +#define U_BRG 0x40
+/* U_MOD bits */ +#define UART_ENABLE BIT(15)
+/* U_STA bits */ +#define UART_RX_ENABLE BIT(12) +#define UART_TX_BRK BIT(11) +#define UART_TX_ENABLE BIT(10) +#define UART_TX_FULL BIT(9) +#define UART_TX_EMPTY BIT(8) +#define UART_RX_OERR BIT(1) +#define UART_RX_DATA_AVAIL BIT(0)
+struct pic32_uart_priv {
void __iomem *base;ulong uartclk;+};
+static void pic32_serial_setbrg(void __iomem *base, ulong uart_clk, u32 baud) +{
writel(0, base + U_BRG);writel((uart_clk / baud / 16) - 1, base + U_BRG);+}
+/*
- Initialize the serial port with the given baudrate.
- The settings are always 8 data bits, no parity, 1 stop bit, no start bits.
- */
+static int pic32_serial_init(void __iomem *base, ulong clk, u32 baudrate) +{
/* wait for TX FIFO to empty */wait_for_bit(__func__, base + U_STA, UART_TX_EMPTY,true, CONFIG_SYS_HZ, false);/* send break */writel(UART_TX_BRK, base + U_STASET);/* disable and clear mode */writel(0, base + U_MOD);writel(0, base + U_STA);/* set baud rate generator */pic32_serial_setbrg(base, clk, baudrate);/* enable the UART for TX and RX */writel(UART_TX_ENABLE | UART_RX_ENABLE, base + U_STASET);/* enable the UART */writel(UART_ENABLE, base + U_MODSET);return 0;+}
+/* Output a single byte to the serial port */ +static void pic32_serial_putc(void __iomem *base, const char c) +{
/* if \n, then add a \r */if (c == '\n')pic32_serial_putc(base, '\r');
you can drop this because the serial uclass code takes care of it
/* Wait for Tx FIFO not full */wait_for_bit(__func__, base + U_STA, UART_TX_FULL,false, CONFIG_SYS_HZ, false);
you should merge this function with pic32_uart_putc(). Then remove the wait loop and only return -EAGAIN if there is no space in the TX FIFO .
/* stuff the tx buffer with the character */writel(c, base + U_TXR);+}
+/* Check number of characters in RX fifo */ +static int pic32_serial_tstc(void __iomem *base) +{
/* check if rx buffer overrun error has occurred */if (readl(base + U_STA) & UART_RX_OERR) {readl(base + U_RXR);/* clear OERR to keep receiving */writel(UART_RX_OERR, base + U_STACLR);}return readl(base + U_STA) & UART_RX_DATA_AVAIL;+}
+/*
- Read a single byte from rx fifo.
- Blocking: waits until a character is received, then returns.
- Return the character read directly from the UART's receive register.
- */
+static int pic32_serial_getc(void __iomem *base) +{
/* return error until data is available */if (!pic32_serial_tstc(base))return -EAGAIN;/* read the character from rx buffer */return readl(base + U_RXR) & 0xff;+}
+static int pic32_uart_pending(struct udevice *dev, bool input) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);if (input)return pic32_serial_tstc(priv->base);return !(readl(priv->base + U_STA) & UART_TX_EMPTY);+}
+static int pic32_uart_setbrg(struct udevice *dev, int baudrate) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);pic32_serial_init(priv->base, priv->uartclk, baudrate);return 0;+}
+static int pic32_uart_putc(struct udevice *dev, const char ch) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);pic32_serial_putc(priv->base, ch);return 0;+}
+static int pic32_uart_getc(struct udevice *dev) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);return pic32_serial_getc(priv->base);+}
+static int pic32_uart_probe(struct udevice *dev) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);pic32_serial_init(priv->base, priv->uartclk, CONFIG_BAUDRATE);return 0;+}
+static int pic32_uart_ofdata_to_platdata(struct udevice *dev) +{
struct pic32_uart_priv *priv = dev_get_platdata(dev);struct udevice *clkdev;fdt_addr_t addr;int ret;/* get address */addr = dev_get_addr(dev);if (addr == FDT_ADDR_T_NONE)return -EINVAL;priv->base = pic32_ioremap(addr);/* get clock rate */ret = uclass_get_device(UCLASS_CLK, 0, &clkdev);if (ret) {printf("clk class not found, %d\n", ret);return ret;}priv->uartclk = clk_get_periph_rate(clkdev, PB2CLK);
all that code could be done in pic32_uart_probe(). you do not need to implement ofdata_to_platdata in DT-only drivers
return 0;+}
+static const struct dm_serial_ops pic32_uart_ops = {
.putc = pic32_uart_putc,.pending = pic32_uart_pending,.getc = pic32_uart_getc,.setbrg = pic32_uart_setbrg,+};
+static const struct udevice_id pic32_uart_ids[] = {
{ .compatible = "microchip,pic32mzda-uart" },{}+};
+U_BOOT_DRIVER(pic32_serial) = {
.name = "pic32-uart",.id = UCLASS_SERIAL,.of_match = pic32_uart_ids,.probe = pic32_uart_probe,.ops = &pic32_uart_ops,.flags = DM_FLAG_PRE_RELOC,.ofdata_to_platdata = pic32_uart_ofdata_to_platdata,.platdata_auto_alloc_size = sizeof(struct pic32_uart_priv),
allocation of driver private data should be requested with priv_auto_alloc_size
+};
+#ifdef CONFIG_DEBUG_UART_PIC32 +#include <debug_uart.h>
+static inline void _debug_uart_init(void) +{
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;pic32_serial_init(base, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);+}
+static inline void _debug_uart_putc(int ch) +{
writel(ch, CONFIG_DEBUG_UART_BASE + U_TXR);+}
+DEBUG_UART_FUNCS
+#endif
1.8.3.1