1/*
  2 * Driver for Samsung S3C6400 and S3C6410 SoC onboard UARTs.
  3 *
  4 * Copyright 2008 Openmoko,  Inc.
  5 * Copyright 2008 Simtec Electronics
  6 *	Ben Dooks <ben@simtec.co.uk>
  7 *	http://armlinux.simtec.co.uk/
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License version 2 as
 11 * published by the Free Software Foundation.
 12*/
 13
 14#include <linux/module.h>
 15#include <linux/ioport.h>
 16#include <linux/io.h>
 17#include <linux/platform_device.h>
 18#include <linux/init.h>
 19#include <linux/serial_core.h>
 20#include <linux/serial.h>
 21
 22#include <asm/irq.h>
 23#include <mach/hardware.h>
 24
 25#include <plat/regs-serial.h>
 26
 27#include "samsung.h"
 28
 29static int s3c6400_serial_setsource(struct uart_port *port,
 30				    struct s3c24xx_uart_clksrc *clk)
 31{
 32	unsigned long ucon = rd_regl(port, S3C2410_UCON);
 33
 34	if (strcmp(clk->name, "uclk0") == 0) {
 35		ucon &= ~S3C6400_UCON_CLKMASK;
 36		ucon |= S3C6400_UCON_UCLK0;
 37	} else if (strcmp(clk->name, "uclk1") == 0)
 38		ucon |= S3C6400_UCON_UCLK1;
 39	else if (strcmp(clk->name, "pclk") == 0) {
 40		/* See notes about transitioning from UCLK to PCLK */
 41		ucon &= ~S3C6400_UCON_UCLK0;
 42	} else {
 43		printk(KERN_ERR "unknown clock source %s\n", clk->name);
 44		return -EINVAL;
 45	}
 46
 47	wr_regl(port, S3C2410_UCON, ucon);
 48	return 0;
 49}
 50
 51
 52static int s3c6400_serial_getsource(struct uart_port *port,
 53				    struct s3c24xx_uart_clksrc *clk)
 54{
 55	u32 ucon = rd_regl(port, S3C2410_UCON);
 56
 57	clk->divisor = 1;
 58
 59	switch (ucon & S3C6400_UCON_CLKMASK) {
 60	case S3C6400_UCON_UCLK0:
 61		clk->name = "uclk0";
 62		break;
 63
 64	case S3C6400_UCON_UCLK1:
 65		clk->name = "uclk1";
 66		break;
 67
 68	case S3C6400_UCON_PCLK:
 69	case S3C6400_UCON_PCLK2:
 70		clk->name = "pclk";
 71		break;
 72	}
 73
 74	return 0;
 75}
 76
 77static int s3c6400_serial_resetport(struct uart_port *port,
 78				    struct s3c2410_uartcfg *cfg)
 79{
 80	unsigned long ucon = rd_regl(port, S3C2410_UCON);
 81
 82	dbg("s3c6400_serial_resetport: port=%p (%08lx), cfg=%p\n",
 83	    port, port->mapbase, cfg);
 84
 85	/* ensure we don't change the clock settings... */
 86
 87	ucon &= S3C6400_UCON_CLKMASK;
 88
 89	wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
 90	wr_regl(port, S3C2410_ULCON, cfg->ulcon);
 91
 92	/* reset both fifos */
 93
 94	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
 95	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
 96
 97	return 0;
 98}
 99
100static struct s3c24xx_uart_info s3c6400_uart_inf = {
101	.name		= "Samsung S3C6400 UART",
102	.type		= PORT_S3C6400,
103	.fifosize	= 64,
104	.has_divslot	= 1,
105	.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
106	.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
107	.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
108	.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
109	.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
110	.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
111	.get_clksrc	= s3c6400_serial_getsource,
112	.set_clksrc	= s3c6400_serial_setsource,
113	.reset_port	= s3c6400_serial_resetport,
114};
115
116/* device management */
117
118static int s3c6400_serial_probe(struct platform_device *dev)
119{
120	dbg("s3c6400_serial_probe: dev=%p\n", dev);
121	return s3c24xx_serial_probe(dev, &s3c6400_uart_inf);
122}
123
124static struct platform_driver s3c6400_serial_driver = {
125	.probe		= s3c6400_serial_probe,
126	.remove		= __devexit_p(s3c24xx_serial_remove),
127	.driver		= {
128		.name	= "s3c6400-uart",
129		.owner	= THIS_MODULE,
130	},
131};
132
133static int __init s3c6400_serial_init(void)
134{
135	return s3c24xx_serial_init(&s3c6400_serial_driver, &s3c6400_uart_inf);
136}
137
138static void __exit s3c6400_serial_exit(void)
139{
140	platform_driver_unregister(&s3c6400_serial_driver);
141}
142
143module_init(s3c6400_serial_init);
144module_exit(s3c6400_serial_exit);
145
146MODULE_DESCRIPTION("Samsung S3C6400,S3C6410 SoC Serial port driver");
147MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
148MODULE_LICENSE("GPL v2");
149MODULE_ALIAS("platform:s3c6400-uart");