diff options
Diffstat (limited to 'arch/arm/mach-davinci/serial.c')
-rw-r--r-- | arch/arm/mach-davinci/serial.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c new file mode 100644 index 000000000..951b620bf --- /dev/null +++ b/arch/arm/mach-davinci/serial.c @@ -0,0 +1,106 @@ +/* + * TI DaVinci serial driver + * + * Copyright (C) 2006 Texas Instruments. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/serial_8250.h> +#include <linux/serial_reg.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include <mach/serial.h> +#include <mach/cputype.h> + +static inline void serial_write_reg(struct plat_serial8250_port *p, int offset, + int value) +{ + offset <<= p->regshift; + + WARN_ONCE(!p->membase, "unmapped write: uart[%d]\n", offset); + + __raw_writel(value, p->membase + offset); +} + +static void __init davinci_serial_reset(struct plat_serial8250_port *p) +{ + unsigned int pwremu = 0; + + serial_write_reg(p, UART_IER, 0); /* disable all interrupts */ + + /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */ + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); + mdelay(10); + + pwremu |= (0x3 << 13); + pwremu |= 0x1; + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); + + if (cpu_is_davinci_dm646x()) + serial_write_reg(p, UART_DM646X_SCR, + UART_DM646X_SCR_TX_WATERMARK); +} + +int __init davinci_serial_init(struct platform_device *serial_dev) +{ + int i, ret = 0; + struct device *dev; + struct plat_serial8250_port *p; + struct clk *clk; + + /* + * Make sure the serial ports are muxed on at this point. + * You have to mux them off in device drivers later on if not needed. + */ + for (i = 0; serial_dev[i].dev.platform_data != NULL; i++) { + dev = &serial_dev[i].dev; + p = dev->platform_data; + + ret = platform_device_register(&serial_dev[i]); + if (ret) + continue; + + clk = clk_get(dev, NULL); + if (IS_ERR(clk)) { + pr_err("%s:%d: failed to get UART%d clock\n", + __func__, __LINE__, i); + continue; + } + + clk_prepare_enable(clk); + + p->uartclk = clk_get_rate(clk); + + if (!p->membase && p->mapbase) { + p->membase = ioremap(p->mapbase, SZ_4K); + + if (p->membase) + p->flags &= ~UPF_IOREMAP; + else + pr_err("uart regs ioremap failed\n"); + } + + if (p->membase && p->type != PORT_AR7) + davinci_serial_reset(p); + } + return ret; +} |