/* * 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 unsigned int serial_read_reg(struct plat_serial8250_port *up, int offset) { offset <<= up->regshift; WARN_ONCE(!up->membase, "unmapped read: uart[%d]\n", offset); return (unsigned int)__raw_readl(up->membase + offset); } 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 davinci_uart_config *info) { int i; char name[16]; struct clk *uart_clk; struct davinci_soc_info *soc_info = &davinci_soc_info; struct device *dev = &soc_info->serial_dev->dev; struct plat_serial8250_port *p = dev->platform_data; /* * 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; p->flags; i++, p++) { if (!(info->enabled_uarts & (1 << i))) continue; sprintf(name, "uart%d", i); uart_clk = clk_get(dev, name); if (IS_ERR(uart_clk)) { printk(KERN_ERR "%s:%d: failed to get UART%d clock\n", __func__, __LINE__, i); continue; } clk_enable(uart_clk); p->uartclk = clk_get_rate(uart_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 platform_device_register(soc_info->serial_dev); }