181 lines
4.4 KiB
C
181 lines
4.4 KiB
C
/*
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* Driver for Samsung S3C2440 and S3C2442 SoC onboard UARTs.
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*
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* Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
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* http://armlinux.simtec.co.uk/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/io.h>
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#include <linux/platform_device.h>
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#include <linux/init.h>
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#include <linux/serial_core.h>
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#include <linux/serial.h>
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#include <asm/irq.h>
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#include <mach/hardware.h>
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#include <plat/regs-serial.h>
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#include <mach/regs-gpio.h>
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#include "samsung.h"
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static int s3c2440_serial_setsource(struct uart_port *port,
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struct s3c24xx_uart_clksrc *clk)
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{
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unsigned long ucon = rd_regl(port, S3C2410_UCON);
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/* todo - proper fclk<>nonfclk switch. */
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ucon &= ~S3C2440_UCON_CLKMASK;
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if (strcmp(clk->name, "uclk") == 0)
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ucon |= S3C2440_UCON_UCLK;
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else if (strcmp(clk->name, "pclk") == 0)
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ucon |= S3C2440_UCON_PCLK;
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else if (strcmp(clk->name, "fclk") == 0)
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ucon |= S3C2440_UCON_FCLK;
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else {
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printk(KERN_ERR "unknown clock source %s\n", clk->name);
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return -EINVAL;
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}
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wr_regl(port, S3C2410_UCON, ucon);
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return 0;
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}
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static int s3c2440_serial_getsource(struct uart_port *port,
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struct s3c24xx_uart_clksrc *clk)
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{
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unsigned long ucon = rd_regl(port, S3C2410_UCON);
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unsigned long ucon0, ucon1, ucon2;
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switch (ucon & S3C2440_UCON_CLKMASK) {
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case S3C2440_UCON_UCLK:
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clk->divisor = 1;
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clk->name = "uclk";
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break;
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case S3C2440_UCON_PCLK:
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case S3C2440_UCON_PCLK2:
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clk->divisor = 1;
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clk->name = "pclk";
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break;
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case S3C2440_UCON_FCLK:
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/* the fun of calculating the uart divisors on
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* the s3c2440 */
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ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
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ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
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ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);
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printk("ucons: %08lx, %08lx, %08lx\n", ucon0, ucon1, ucon2);
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ucon0 &= S3C2440_UCON0_DIVMASK;
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ucon1 &= S3C2440_UCON1_DIVMASK;
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ucon2 &= S3C2440_UCON2_DIVMASK;
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if (ucon0 != 0) {
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clk->divisor = ucon0 >> S3C2440_UCON_DIVSHIFT;
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clk->divisor += 6;
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} else if (ucon1 != 0) {
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clk->divisor = ucon1 >> S3C2440_UCON_DIVSHIFT;
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clk->divisor += 21;
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} else if (ucon2 != 0) {
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clk->divisor = ucon2 >> S3C2440_UCON_DIVSHIFT;
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clk->divisor += 36;
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} else {
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/* manual calims 44, seems to be 9 */
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clk->divisor = 9;
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}
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clk->name = "fclk";
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break;
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}
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return 0;
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}
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static int s3c2440_serial_resetport(struct uart_port *port,
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struct s3c2410_uartcfg *cfg)
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{
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unsigned long ucon = rd_regl(port, S3C2410_UCON);
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dbg("s3c2440_serial_resetport: port=%p (%08lx), cfg=%p\n",
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port, port->mapbase, cfg);
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/* ensure we don't change the clock settings... */
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ucon &= (S3C2440_UCON0_DIVMASK | (3<<10));
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wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
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wr_regl(port, S3C2410_ULCON, cfg->ulcon);
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/* reset both fifos */
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wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
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wr_regl(port, S3C2410_UFCON, cfg->ufcon);
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return 0;
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}
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static struct s3c24xx_uart_info s3c2440_uart_inf = {
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.name = "Samsung S3C2440 UART",
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.type = PORT_S3C2440,
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.fifosize = 64,
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.rx_fifomask = S3C2440_UFSTAT_RXMASK,
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.rx_fifoshift = S3C2440_UFSTAT_RXSHIFT,
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.rx_fifofull = S3C2440_UFSTAT_RXFULL,
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.tx_fifofull = S3C2440_UFSTAT_TXFULL,
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.tx_fifomask = S3C2440_UFSTAT_TXMASK,
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.tx_fifoshift = S3C2440_UFSTAT_TXSHIFT,
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.get_clksrc = s3c2440_serial_getsource,
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.set_clksrc = s3c2440_serial_setsource,
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.reset_port = s3c2440_serial_resetport,
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};
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/* device management */
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static int s3c2440_serial_probe(struct platform_device *dev)
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{
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dbg("s3c2440_serial_probe: dev=%p\n", dev);
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return s3c24xx_serial_probe(dev, &s3c2440_uart_inf);
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}
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static struct platform_driver s3c2440_serial_driver = {
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.probe = s3c2440_serial_probe,
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.remove = __devexit_p(s3c24xx_serial_remove),
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.driver = {
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.name = "s3c2440-uart",
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.owner = THIS_MODULE,
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},
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};
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s3c24xx_console_init(&s3c2440_serial_driver, &s3c2440_uart_inf);
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static int __init s3c2440_serial_init(void)
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{
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return s3c24xx_serial_init(&s3c2440_serial_driver, &s3c2440_uart_inf);
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}
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static void __exit s3c2440_serial_exit(void)
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{
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platform_driver_unregister(&s3c2440_serial_driver);
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}
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module_init(s3c2440_serial_init);
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module_exit(s3c2440_serial_exit);
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MODULE_DESCRIPTION("Samsung S3C2440,S3C2442 SoC Serial port driver");
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MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:s3c2440-uart");
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