* [U-Boot] [PATCH v2 04/13] drivers: serial: add driver for Microchip PIC32 UART controller.
@ 2016-01-04 14:00 Purna Chandra Mandal
2016-01-05 19:59 ` Daniel Schwierzeck
0 siblings, 1 reply; 3+ messages in thread
From: Purna Chandra Mandal @ 2016-01-04 14:00 UTC (permalink / raw)
To: u-boot
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"
+ help
+ Select this to enable a debug UART using the serial_pic32 driver. You
+ will need to provide parameters to make this work. The driver will
+ be 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"
+ help
+ Support 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');
+
+ /* Wait for Tx FIFO not full */
+ wait_for_bit(__func__, base + U_STA, UART_TX_FULL,
+ false, CONFIG_SYS_HZ, false);
+
+ /* 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);
+
+ 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),
+};
+
+#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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [U-Boot] [PATCH v2 04/13] drivers: serial: add driver for Microchip PIC32 UART controller.
2016-01-04 14:00 [U-Boot] [PATCH v2 04/13] drivers: serial: add driver for Microchip PIC32 UART controller Purna Chandra Mandal
@ 2016-01-05 19:59 ` Daniel Schwierzeck
2016-01-06 8:07 ` Purna Chandra Mandal
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Schwierzeck @ 2016-01-05 19:59 UTC (permalink / raw)
To: u-boot
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"
> + help
> + Select this to enable a debug UART using the serial_pic32 driver. You
> + will need to provide parameters to make this work. The driver will
> + be 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"
> + help
> + Support 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
>
>
--
- Daniel
^ permalink raw reply [flat|nested] 3+ messages in thread
* [U-Boot] [PATCH v2 04/13] drivers: serial: add driver for Microchip PIC32 UART controller.
2016-01-05 19:59 ` Daniel Schwierzeck
@ 2016-01-06 8:07 ` Purna Chandra Mandal
0 siblings, 0 replies; 3+ messages in thread
From: Purna Chandra Mandal @ 2016-01-06 8:07 UTC (permalink / raw)
To: u-boot
On 01/06/2016 01:29 AM, Daniel Schwierzeck wrote:
> 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"
>> + help
>> + Select this to enable a debug UART using the serial_pic32 driver. You
>> + will need to provide parameters to make this work. The driver will
>> + be 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"
>> + help
>> + Support 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
ack. Will remove.
>> +
>> + /* 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
> .
ack.
>> +
>> + /* 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
ack. Will move these to _probe().
>> +
>> + 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
ack.
>> +};
>> +
>> +#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
>>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-01-06 8:07 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-01-04 14:00 [U-Boot] [PATCH v2 04/13] drivers: serial: add driver for Microchip PIC32 UART controller Purna Chandra Mandal
2016-01-05 19:59 ` Daniel Schwierzeck
2016-01-06 8:07 ` Purna Chandra Mandal
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