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authorAntony Pavlov <antonynpavlov@gmail.com>2014-03-28 01:26:39 +0400
committerSascha Hauer <s.hauer@pengutronix.de>2014-03-28 10:28:15 +0100
commitdbee996459f847119243c08a355334bff394f94d (patch)
treea61167e9432b97b40aecd6ed970fe88490e4731e /drivers
parentcf93dcd0dbb55a4fd45a0a02e167cc642248785d (diff)
downloadbarebox-dbee996459f847119243c08a355334bff394f94d.tar.gz
barebox-dbee996459f847119243c08a355334bff394f94d.tar.xz
serial: add Atheros AR933x driver
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com> Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/serial/Kconfig7
-rw-r--r--drivers/serial/Makefile1
-rw-r--r--drivers/serial/serial_ar933x.c204
-rw-r--r--drivers/serial/serial_ar933x.h69
4 files changed, 281 insertions, 0 deletions
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 11fc15507..f51c6e6b0 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -14,6 +14,13 @@ config SERIAL_AMBA_PL011
If unsure, say N.
+config DRIVER_SERIAL_AR933X
+ bool "AR933X serial driver"
+ depends on MACH_MIPS_ATH79
+ help
+ If you have an Atheros AR933X SOC based board and want to use the
+ built-in UART of the SoC, say Y to this option.
+
config DRIVER_SERIAL_IMX
depends on ARCH_IMX
default y
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 93790b534..e1865f725 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_DRIVER_SERIAL_ARM_DCC) += arm_dcc.o
obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
+obj-$(CONFIG_DRIVER_SERIAL_AR933X) += serial_ar933x.o
obj-$(CONFIG_DRIVER_SERIAL_IMX) += serial_imx.o
obj-$(CONFIG_DRIVER_SERIAL_STM378X) += stm-serial.o
obj-$(CONFIG_DRIVER_SERIAL_ATMEL) += atmel.o
diff --git a/drivers/serial/serial_ar933x.c b/drivers/serial/serial_ar933x.c
new file mode 100644
index 000000000..27cccba11
--- /dev/null
+++ b/drivers/serial/serial_ar933x.c
@@ -0,0 +1,204 @@
+/*
+ * based on linux.git/drivers/tty/serial/serial_ar933x.c
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <malloc.h>
+#include <io.h>
+#include <asm-generic/div64.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#include "serial_ar933x.h"
+
+#define AR933X_UART_MAX_SCALE 0xff
+#define AR933X_UART_MAX_STEP 0xffff
+
+struct ar933x_uart_priv {
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static inline void ar933x_serial_writel(struct console_device *cdev,
+ u32 b, int offset)
+{
+ struct ar933x_uart_priv *priv = cdev->dev->priv;
+
+ cpu_writel(b, priv->base + offset);
+}
+
+static inline u32 ar933x_serial_readl(struct console_device *cdev,
+ int offset)
+{
+ struct ar933x_uart_priv *priv = cdev->dev->priv;
+
+ return cpu_readl(priv->base + offset);
+}
+
+/*
+ * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
+ * take from linux.
+ */
+static unsigned long ar933x_uart_get_baud(unsigned int clk,
+ unsigned int scale,
+ unsigned int step)
+{
+ u64 t;
+ u32 div;
+
+ div = (2 << 16) * (scale + 1);
+ t = clk;
+ t *= step;
+ t += (div / 2);
+ do_div(t, div);
+
+ return t;
+}
+
+static void ar933x_uart_get_scale_step(unsigned int clk,
+ unsigned int baud,
+ unsigned int *scale,
+ unsigned int *step)
+{
+ unsigned int tscale;
+ long min_diff;
+
+ *scale = 0;
+ *step = 0;
+
+ min_diff = baud;
+ for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
+ u64 tstep;
+ int diff;
+
+ tstep = baud * (tscale + 1);
+ tstep *= (2 << 16);
+ do_div(tstep, clk);
+
+ if (tstep > AR933X_UART_MAX_STEP)
+ break;
+
+ diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
+ if (diff < min_diff) {
+ min_diff = diff;
+ *scale = tscale;
+ *step = tstep;
+ }
+ }
+}
+
+static int ar933x_serial_setbaudrate(struct console_device *cdev, int baudrate)
+{
+ struct ar933x_uart_priv *priv = cdev->dev->priv;
+ unsigned int scale, step;
+
+ ar933x_uart_get_scale_step(clk_get_rate(priv->clk), baudrate, &scale,
+ &step);
+ ar933x_serial_writel(cdev, (scale << AR933X_UART_CLOCK_SCALE_S) | step,
+ AR933X_UART_CLOCK_REG);
+
+ return 0;
+}
+
+static void ar933x_serial_putc(struct console_device *cdev, char ch)
+{
+ u32 data;
+
+ /* wait transmitter ready */
+ data = ar933x_serial_readl(cdev, AR933X_UART_DATA_REG);
+ while (!(data & AR933X_UART_DATA_TX_CSR))
+ data = ar933x_serial_readl(cdev, AR933X_UART_DATA_REG);
+
+ data = (ch & AR933X_UART_DATA_TX_RX_MASK) | AR933X_UART_DATA_TX_CSR;
+ ar933x_serial_writel(cdev, data, AR933X_UART_DATA_REG);
+}
+
+static int ar933x_serial_tstc(struct console_device *cdev)
+{
+ u32 rdata;
+
+ rdata = ar933x_serial_readl(cdev, AR933X_UART_DATA_REG);
+
+ return rdata & AR933X_UART_DATA_RX_CSR;
+}
+
+static int ar933x_serial_getc(struct console_device *cdev)
+{
+ u32 rdata;
+
+ while (!ar933x_serial_tstc(cdev))
+ ;
+
+ rdata = ar933x_serial_readl(cdev, AR933X_UART_DATA_REG);
+
+ /* remove the character from the FIFO */
+ ar933x_serial_writel(cdev, AR933X_UART_DATA_RX_CSR,
+ AR933X_UART_DATA_REG);
+
+ return rdata & AR933X_UART_DATA_TX_RX_MASK;
+}
+
+static int ar933x_serial_probe(struct device_d *dev)
+{
+ struct console_device *cdev;
+ struct ar933x_uart_priv *priv;
+ u32 uart_cs;
+
+ cdev = xzalloc(sizeof(struct console_device));
+ priv = xzalloc(sizeof(struct ar933x_uart_priv));
+ priv->base = dev_request_mem_region(dev, 0);
+ dev->priv = priv;
+
+ cdev->dev = dev;
+ cdev->tstc = ar933x_serial_tstc;
+ cdev->putc = ar933x_serial_putc;
+ cdev->getc = ar933x_serial_getc;
+ cdev->setbrg = ar933x_serial_setbaudrate;
+
+ priv->clk = clk_get(dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(dev, "unable to get UART clock\n");
+ return PTR_ERR(priv->clk);
+ }
+
+ uart_cs = (AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S)
+ | AR933X_UART_CS_TX_READY_ORIDE
+ | AR933X_UART_CS_RX_READY_ORIDE;
+ ar933x_serial_writel(cdev, uart_cs, AR933X_UART_CS_REG);
+ /* FIXME: need ar933x_serial_init_port(cdev); */
+
+ console_register(cdev);
+
+ return 0;
+}
+
+static struct of_device_id ar933x_serial_dt_ids[] = {
+ {
+ .compatible = "qca,ar9330-uart",
+ }, {
+ /* sentinel */
+ },
+};
+
+static struct driver_d ar933x_serial_driver = {
+ .name = "ar933x_serial",
+ .probe = ar933x_serial_probe,
+ .of_compatible = DRV_OF_COMPAT(ar933x_serial_dt_ids),
+};
+console_platform_driver(ar933x_serial_driver);
diff --git a/drivers/serial/serial_ar933x.h b/drivers/serial/serial_ar933x.h
new file mode 100644
index 000000000..f55f0fa3d
--- /dev/null
+++ b/drivers/serial/serial_ar933x.h
@@ -0,0 +1,69 @@
+/*
+ * Atheros AR933X UART defines
+ *
+ * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#ifndef __AR933X_UART_H
+#define __AR933X_UART_H
+
+#include <linux/bitops.h>
+
+#define AR933X_UART_REGS_SIZE 20
+#define AR933X_UART_FIFO_SIZE 16
+
+#define AR933X_UART_DATA_REG 0x00
+#define AR933X_UART_CS_REG 0x04
+#define AR933X_UART_CLOCK_REG 0x08
+#define AR933X_UART_INT_REG 0x0c
+#define AR933X_UART_INT_EN_REG 0x10
+
+#define AR933X_UART_DATA_TX_RX_MASK 0xff
+#define AR933X_UART_DATA_RX_CSR BIT(8)
+#define AR933X_UART_DATA_TX_CSR BIT(9)
+
+#define AR933X_UART_CS_PARITY_S 0
+#define AR933X_UART_CS_PARITY_M 0x3
+#define AR933X_UART_CS_PARITY_NONE 0
+#define AR933X_UART_CS_PARITY_ODD 1
+#define AR933X_UART_CS_PARITY_EVEN 2
+#define AR933X_UART_CS_IF_MODE_S 2
+#define AR933X_UART_CS_IF_MODE_M 0x3
+#define AR933X_UART_CS_IF_MODE_NONE 0
+#define AR933X_UART_CS_IF_MODE_DTE 1
+#define AR933X_UART_CS_IF_MODE_DCE 2
+#define AR933X_UART_CS_FLOW_CTRL_S 4
+#define AR933X_UART_CS_FLOW_CTRL_M 0x3
+#define AR933X_UART_CS_DMA_EN BIT(6)
+#define AR933X_UART_CS_TX_READY_ORIDE BIT(7)
+#define AR933X_UART_CS_RX_READY_ORIDE BIT(8)
+#define AR933X_UART_CS_TX_READY BIT(9)
+#define AR933X_UART_CS_RX_BREAK BIT(10)
+#define AR933X_UART_CS_TX_BREAK BIT(11)
+#define AR933X_UART_CS_HOST_INT BIT(12)
+#define AR933X_UART_CS_HOST_INT_EN BIT(13)
+#define AR933X_UART_CS_TX_BUSY BIT(14)
+#define AR933X_UART_CS_RX_BUSY BIT(15)
+
+#define AR933X_UART_CLOCK_STEP_M 0xffff
+#define AR933X_UART_CLOCK_SCALE_M 0xfff
+#define AR933X_UART_CLOCK_SCALE_S 16
+#define AR933X_UART_CLOCK_STEP_M 0xffff
+
+#define AR933X_UART_INT_RX_VALID BIT(0)
+#define AR933X_UART_INT_TX_READY BIT(1)
+#define AR933X_UART_INT_RX_FRAMING_ERR BIT(2)
+#define AR933X_UART_INT_RX_OFLOW_ERR BIT(3)
+#define AR933X_UART_INT_TX_OFLOW_ERR BIT(4)
+#define AR933X_UART_INT_RX_PARITY_ERR BIT(5)
+#define AR933X_UART_INT_RX_BREAK_ON BIT(6)
+#define AR933X_UART_INT_RX_BREAK_OFF BIT(7)
+#define AR933X_UART_INT_RX_FULL BIT(8)
+#define AR933X_UART_INT_TX_EMPTY BIT(9)
+#define AR933X_UART_INT_ALLINTS 0x3ff
+
+#endif /* __AR933X_UART_H */