From dbee996459f847119243c08a355334bff394f94d Mon Sep 17 00:00:00 2001 From: Antony Pavlov Date: Fri, 28 Mar 2014 01:26:39 +0400 Subject: serial: add Atheros AR933x driver Signed-off-by: Antony Pavlov Signed-off-by: Oleksij Rempel Signed-off-by: Sascha Hauer --- drivers/serial/Kconfig | 7 ++ drivers/serial/Makefile | 1 + drivers/serial/serial_ar933x.c | 204 +++++++++++++++++++++++++++++++++++++++++ drivers/serial/serial_ar933x.h | 69 ++++++++++++++ 4 files changed, 281 insertions(+) create mode 100644 drivers/serial/serial_ar933x.c create mode 100644 drivers/serial/serial_ar933x.h (limited to 'drivers') diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 11fc155074..f51c6e6b02 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 93790b5349..e1865f725a 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 0000000000..27cccba119 --- /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 +#include +#include +#include +#include +#include +#include +#include + +#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 0000000000..f55f0fa3d7 --- /dev/null +++ b/drivers/serial/serial_ar933x.h @@ -0,0 +1,69 @@ +/* + * Atheros AR933X UART defines + * + * Copyright (C) 2011 Gabor Juhos + * + * 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 + +#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 */ -- cgit v1.2.3