[U-Boot] [PATCH v4 13/15] dm: serial: Add driver model support for ns16550
Simon Glass
sjg at chromium.org
Mon Aug 11 17:27:51 CEST 2014
Add driver model support so that ns16550 can support operation both with
and without driver model.
The driver needs a clock frequency so cannot stand alone unfortunately. The
clock frequency must be provided by a separate driver.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v4:
- Remove clock frequency setup for ns16550 driver
Changes in v3:
- Add new patch to support driver model in ns16550
Changes in v2: None
doc/device-tree-bindings/serial/ns16550.txt | 10 ++
drivers/serial/Makefile | 2 +-
drivers/serial/ns16550.c | 156 +++++++++++++++++++++++++++-
include/ns16550.h | 51 +++++++++
4 files changed, 216 insertions(+), 3 deletions(-)
create mode 100644 doc/device-tree-bindings/serial/ns16550.txt
diff --git a/doc/device-tree-bindings/serial/ns16550.txt b/doc/device-tree-bindings/serial/ns16550.txt
new file mode 100644
index 0000000..ef0b9ae
--- /dev/null
+++ b/doc/device-tree-bindings/serial/ns16550.txt
@@ -0,0 +1,10 @@
+NS16550 UART
+
+This UART driver supports many chip variants and is used in mamy SoCs.
+
+Required properties:
+- compatible: "ns16550" or "nvidia,tegra20-uart"
+- reg: start address and size of registers
+- reg-shift: shift value indicating register size: 0=byte, 1=16bit,2=32bit etc.
+- clock-frequency: input clock frequency for the UART (used to calculate the
+ baud rate divisor)
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 4720e1d..5ae6416 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -9,6 +9,7 @@ ifdef CONFIG_DM_SERIAL
obj-y += serial-uclass.o
else
obj-y += serial.o
+obj-$(CONFIG_SYS_NS16550_SERIAL) += serial_ns16550.o
endif
obj-$(CONFIG_ALTERA_UART) += altera_uart.o
@@ -20,7 +21,6 @@ obj-$(CONFIG_MCFUART) += mcfuart.o
obj-$(CONFIG_OPENCORES_YANU) += opencores_yanu.o
obj-$(CONFIG_SYS_NS16550) += ns16550.o
obj-$(CONFIG_S5P) += serial_s5p.o
-obj-$(CONFIG_SYS_NS16550_SERIAL) += serial_ns16550.o
obj-$(CONFIG_IMX_SERIAL) += serial_imx.o
obj-$(CONFIG_KS8695_SERIAL) += serial_ks8695.o
obj-$(CONFIG_MAX3100_SERIAL) += serial_max3100.o
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 185e7a8..b3e297e 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -5,17 +5,25 @@
*/
#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
#include <ns16550.h>
+#include <serial.h>
#include <watchdog.h>
#include <linux/types.h>
#include <asm/io.h>
+DECLARE_GLOBAL_DATA_PTR;
+
#define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
#define UART_MCRVAL (UART_MCR_DTR | \
UART_MCR_RTS) /* RTS/DTR */
#define UART_FCRVAL (UART_FCR_FIFO_EN | \
UART_FCR_RXSR | \
UART_FCR_TXSR) /* Clear & enable FIFOs */
+
+#ifndef CONFIG_DM_SERIAL
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
#define serial_out(x, y) outb(x, (ulong)y)
#define serial_in(y) inb((ulong)y)
@@ -29,6 +37,7 @@
#define serial_out(x, y) writeb(x, y)
#define serial_in(y) readb(y)
#endif
+#endif /* !CONFIG_DM_SERIAL */
#if defined(CONFIG_SOC_KEYSTONE)
#define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE 0
@@ -45,6 +54,58 @@
#define CONFIG_SYS_NS16550_IER 0x00
#endif /* CONFIG_SYS_NS16550_IER */
+#ifdef CONFIG_DM_SERIAL
+static void ns16550_writeb(NS16550_t port, int offset, int value)
+{
+ struct ns16550_platdata *plat = port->plat;
+ unsigned char *addr;
+
+ offset *= 1 << plat->reg_shift;
+ addr = plat->base + offset;
+ /*
+ * As far as we know it doesn't make sense to support selection of
+ * these options at run-time, so use the existing CONFIG options.
+ */
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+ outb(value, addr);
+#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
+ out_le32(addr, value);
+#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
+ out_be32(addr, value);
+#elif defined(CONFIG_SYS_BIG_ENDIAN)
+ writeb(value, addr + (1 << plat->reg_shift) - 1);
+#else
+ writeb(value, addr);
+#endif
+}
+
+static int ns16550_readb(NS16550_t port, int offset)
+{
+ struct ns16550_platdata *plat = port->plat;
+ unsigned char *addr;
+
+ offset *= 1 << plat->reg_shift;
+ addr = plat->base + offset;
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+ return inb(addr);
+#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
+ return in_le32(addr);
+#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
+ return in_be32(addr);
+#elif defined(CONFIG_SYS_BIG_ENDIAN)
+ return readb(addr + (1 << plat->reg_shift) - 1);
+#else
+ return readb(addr);
+#endif
+}
+
+/* We can clean these up once everything is moved to driver model */
+#define serial_out(value, addr) \
+ ns16550_writeb(com_port, addr - (unsigned char *)com_port, value)
+#define serial_in(addr) \
+ ns16550_readb(com_port, addr - (unsigned char *)com_port)
+#endif
+
int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
{
const unsigned int mode_x_div = 16;
@@ -79,7 +140,8 @@ void NS16550_init(NS16550_t com_port, int baud_divisor)
*/
if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
== UART_LSR_THRE) {
- NS16550_setbrg(com_port, baud_divisor);
+ if (baud_divisor != -1)
+ NS16550_setbrg(com_port, baud_divisor);
serial_out(0, &com_port->mdr1);
}
#endif
@@ -95,7 +157,8 @@ void NS16550_init(NS16550_t com_port, int baud_divisor)
NS16550_setbrg(com_port, 0);
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(UART_FCRVAL, &com_port->fcr);
- NS16550_setbrg(com_port, baud_divisor);
+ if (baud_divisor != -1)
+ NS16550_setbrg(com_port, baud_divisor);
#if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
@@ -154,3 +217,92 @@ int NS16550_tstc(NS16550_t com_port)
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
+
+#ifdef CONFIG_DM_SERIAL
+static int ns16550_serial_putc(struct udevice *dev, const char ch)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+
+ if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
+ return -EAGAIN;
+ serial_out(ch, &com_port->thr);
+
+ /*
+ * Call watchdog_reset() upon newline. This is done here in putc
+ * since the environment code uses a single puts() to print the complete
+ * environment upon "printenv". So we can't put this watchdog call
+ * in puts().
+ */
+ if (ch == '\n')
+ WATCHDOG_RESET();
+
+ return 0;
+}
+
+static int ns16550_serial_pending(struct udevice *dev, bool input)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+
+ if (input)
+ return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
+ else
+ return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
+}
+
+static int ns16550_serial_getc(struct udevice *dev)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+
+ if (!serial_in(&com_port->lsr) & UART_LSR_DR)
+ return -EAGAIN;
+
+ return serial_in(&com_port->rbr);
+}
+
+static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+ struct ns16550_platdata *plat = com_port->plat;
+ int clock_divisor;
+
+ clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
+
+ NS16550_setbrg(com_port, clock_divisor);
+
+ return 0;
+}
+
+int ns16550_serial_probe(struct udevice *dev)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+
+ NS16550_init(com_port, -1);
+
+ return 0;
+}
+
+int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+ struct ns16550_platdata *plat = dev->platdata;
+ fdt_addr_t addr;
+
+ addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ plat->base = (unsigned char *)addr;
+ plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+ "reg-shift", 1);
+ com_port->plat = plat;
+
+ return 0;
+}
+
+const struct dm_serial_ops ns16550_serial_ops = {
+ .putc = ns16550_serial_putc,
+ .pending = ns16550_serial_pending,
+ .getc = ns16550_serial_getc,
+ .setbrg = ns16550_serial_setbrg,
+};
+#endif /* CONFIG_DM_SERIAL */
diff --git a/include/ns16550.h b/include/ns16550.h
index b106f8a..9212c68 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -23,6 +23,14 @@
#include <linux/types.h>
+#ifdef CONFIG_DM_SERIAL
+/*
+ * For driver model we always use one byte per register, and sort out the
+ * differences in the driver
+ */
+#define CONFIG_SYS_NS16550_REG_SIZE (-1)
+#endif
+
#if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
#error "Please define NS16550 registers size."
#elif defined(CONFIG_SYS_NS16550_MEM32)
@@ -37,6 +45,19 @@
unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1];
#endif
+/**
+ * struct ns16550_platdata - information about a NS16550 port
+ *
+ * @base: Base register address
+ * @reg_shift: Shift size of registers (0=byte, 1=16bit, 2=32bit...)
+ * @clock: UART base clock speed in Hz
+ */
+struct ns16550_platdata {
+ unsigned char *base;
+ int reg_shift;
+ int clock;
+};
+
struct NS16550 {
UART_REG(rbr); /* 0 */
UART_REG(ier); /* 1 */
@@ -67,6 +88,9 @@ struct NS16550 {
UART_REG(reg12); /* 12*/
UART_REG(osc_12m_sel); /* 13*/
#endif
+#ifdef CONFIG_DM_SERIAL
+ struct ns16550_platdata *plat;
+#endif
};
#define thr rbr
@@ -190,3 +214,30 @@ void NS16550_reinit(NS16550_t com_port, int baud_divisor);
* @return baud rate divisor that should be used
*/
int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate);
+
+/**
+ * ns16550_serial_ofdata_to_platdata() - convert DT to platform data
+ *
+ * Decode a device tree node for an ns16550 device. This includes the
+ * register base address and register shift properties. The caller must set
+ * up the clock frequency.
+ *
+ * @dev: dev to decode platform data for
+ * @return: 0 if OK, -EINVAL on error
+ */
+int ns16550_serial_ofdata_to_platdata(struct udevice *dev);
+
+/**
+ * ns16550_serial_probe() - probe a serial port
+ *
+ * This sets up the serial port ready for use, except for the baud rate
+ * @return 0, or -ve on error
+ */
+int ns16550_serial_probe(struct udevice *dev);
+
+/**
+ * struct ns16550_serial_ops - ns16550 serial operations
+ *
+ * These should be used by the client driver for the driver's 'ops' member
+ */
+extern const struct dm_serial_ops ns16550_serial_ops;
--
2.0.0.526.g5318336
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