diff options
Diffstat (limited to 'drivers/tty/serial/s3c2440.c')
| -rw-r--r-- | drivers/tty/serial/s3c2440.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/tty/serial/s3c2440.c b/drivers/tty/serial/s3c2440.c new file mode 100644 index 000000000000..094cc3904b13 --- /dev/null +++ b/drivers/tty/serial/s3c2440.c @@ -0,0 +1,181 @@ +/* linux/drivers/serial/s3c2440.c + * + * Driver for Samsung S3C2440 and S3C2442 SoC onboard UARTs. + * + * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * + * 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. +*/ + +#include <linux/module.h> +#include <linux/ioport.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/init.h> +#include <linux/serial_core.h> +#include <linux/serial.h> + +#include <asm/irq.h> +#include <mach/hardware.h> + +#include <plat/regs-serial.h> +#include <mach/regs-gpio.h> + +#include "samsung.h" + + +static int s3c2440_serial_setsource(struct uart_port *port, + struct s3c24xx_uart_clksrc *clk) +{ + unsigned long ucon = rd_regl(port, S3C2410_UCON); + + /* todo - proper fclk<>nonfclk switch. */ + + ucon &= ~S3C2440_UCON_CLKMASK; + + if (strcmp(clk->name, "uclk") == 0) + ucon |= S3C2440_UCON_UCLK; + else if (strcmp(clk->name, "pclk") == 0) + ucon |= S3C2440_UCON_PCLK; + else if (strcmp(clk->name, "fclk") == 0) + ucon |= S3C2440_UCON_FCLK; + else { + printk(KERN_ERR "unknown clock source %s\n", clk->name); + return -EINVAL; + } + + wr_regl(port, S3C2410_UCON, ucon); + return 0; +} + + +static int s3c2440_serial_getsource(struct uart_port *port, + struct s3c24xx_uart_clksrc *clk) +{ + unsigned long ucon = rd_regl(port, S3C2410_UCON); + unsigned long ucon0, ucon1, ucon2; + + switch (ucon & S3C2440_UCON_CLKMASK) { + case S3C2440_UCON_UCLK: + clk->divisor = 1; + clk->name = "uclk"; + break; + + case S3C2440_UCON_PCLK: + case S3C2440_UCON_PCLK2: + clk->divisor = 1; + clk->name = "pclk"; + break; + + case S3C2440_UCON_FCLK: + /* the fun of calculating the uart divisors on + * the s3c2440 */ + + ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON); + ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON); + ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON); + + printk("ucons: %08lx, %08lx, %08lx\n", ucon0, ucon1, ucon2); + + ucon0 &= S3C2440_UCON0_DIVMASK; + ucon1 &= S3C2440_UCON1_DIVMASK; + ucon2 &= S3C2440_UCON2_DIVMASK; + + if (ucon0 != 0) { + clk->divisor = ucon0 >> S3C2440_UCON_DIVSHIFT; + clk->divisor += 6; + } else if (ucon1 != 0) { + clk->divisor = ucon1 >> S3C2440_UCON_DIVSHIFT; + clk->divisor += 21; + } else if (ucon2 != 0) { + clk->divisor = ucon2 >> S3C2440_UCON_DIVSHIFT; + clk->divisor += 36; + } else { + /* manual calims 44, seems to be 9 */ + clk->divisor = 9; + } + + clk->name = "fclk"; + break; + } + + return 0; +} + +static int s3c2440_serial_resetport(struct uart_port *port, + struct s3c2410_uartcfg *cfg) +{ + unsigned long ucon = rd_regl(port, S3C2410_UCON); + + dbg("s3c2440_serial_resetport: port=%p (%08lx), cfg=%p\n", + port, port->mapbase, cfg); + + /* ensure we don't change the clock settings... */ + + ucon &= (S3C2440_UCON0_DIVMASK | (3<<10)); + + wr_regl(port, S3C2410_UCON, ucon | cfg->ucon); + wr_regl(port, S3C2410_ULCON, cfg->ulcon); + + /* reset both fifos */ + + wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH); + wr_regl(port, S3C2410_UFCON, cfg->ufcon); + + return 0; +} + +static struct s3c24xx_uart_info s3c2440_uart_inf = { + .name = "Samsung S3C2440 UART", + .type = PORT_S3C2440, + .fifosize = 64, + .rx_fifomask = S3C2440_UFSTAT_RXMASK, + .rx_fifoshift = S3C2440_UFSTAT_RXSHIFT, + .rx_fifofull = S3C2440_UFSTAT_RXFULL, + .tx_fifofull = S3C2440_UFSTAT_TXFULL, + .tx_fifomask = S3C2440_UFSTAT_TXMASK, + .tx_fifoshift = S3C2440_UFSTAT_TXSHIFT, + .get_clksrc = s3c2440_serial_getsource, + .set_clksrc = s3c2440_serial_setsource, + .reset_port = s3c2440_serial_resetport, +}; + +/* device management */ + +static int s3c2440_serial_probe(struct platform_device *dev) +{ + dbg("s3c2440_serial_probe: dev=%p\n", dev); + return s3c24xx_serial_probe(dev, &s3c2440_uart_inf); +} + +static struct platform_driver s3c2440_serial_driver = { + .probe = s3c2440_serial_probe, + .remove = __devexit_p(s3c24xx_serial_remove), + .driver = { + .name = "s3c2440-uart", + .owner = THIS_MODULE, + }, +}; + +s3c24xx_console_init(&s3c2440_serial_driver, &s3c2440_uart_inf); + +static int __init s3c2440_serial_init(void) +{ + return s3c24xx_serial_init(&s3c2440_serial_driver, &s3c2440_uart_inf); +} + +static void __exit s3c2440_serial_exit(void) +{ + platform_driver_unregister(&s3c2440_serial_driver); +} + +module_init(s3c2440_serial_init); +module_exit(s3c2440_serial_exit); + +MODULE_DESCRIPTION("Samsung S3C2440,S3C2442 SoC Serial port driver"); +MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:s3c2440-uart"); |