diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/samsung_tty.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 0cf4dfe77c32..857afcd5fe2d 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -65,6 +65,7 @@ enum s3c24xx_port_type { struct s3c24xx_uart_info { char *name; enum s3c24xx_port_type type; + unsigned int has_usi; unsigned int port_type; unsigned int fifosize; unsigned long rx_fifomask; @@ -1356,6 +1357,28 @@ static int apple_s5l_serial_startup(struct uart_port *port) return ret; } +static void exynos_usi_init(struct uart_port *port) +{ + struct s3c24xx_uart_port *ourport = to_ourport(port); + struct s3c24xx_uart_info *info = ourport->info; + unsigned int val; + + if (!info->has_usi) + return; + + /* Clear the software reset of USI block (it's set at startup) */ + val = rd_regl(port, USI_CON); + val &= ~USI_CON_RESET_MASK; + wr_regl(port, USI_CON, val); + udelay(1); + + /* Continuously provide the clock to USI IP w/o gating (for Rx mode) */ + val = rd_regl(port, USI_OPTION); + val &= ~USI_OPTION_HWACG_MASK; + val |= USI_OPTION_HWACG_CLKREQ_ON; + wr_regl(port, USI_OPTION, val); +} + /* power power management control */ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, @@ -1383,6 +1406,7 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, if (!IS_ERR(ourport->baudclk)) clk_prepare_enable(ourport->baudclk); + exynos_usi_init(port); break; default: dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level); @@ -2106,6 +2130,8 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport, if (ret) pr_warn("uart: failed to enable baudclk\n"); + exynos_usi_init(port); + /* Keep all interrupts masked and cleared */ switch (ourport->info->type) { case TYPE_S3C6400: @@ -2754,10 +2780,11 @@ static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = { #endif #if defined(CONFIG_ARCH_EXYNOS) -#define EXYNOS_COMMON_SERIAL_DRV_DATA \ +#define EXYNOS_COMMON_SERIAL_DRV_DATA_USI(_has_usi) \ .info = &(struct s3c24xx_uart_info) { \ .name = "Samsung Exynos UART", \ .type = TYPE_S3C6400, \ + .has_usi = _has_usi, \ .port_type = PORT_S3C6400, \ .has_divslot = 1, \ .rx_fifomask = S5PV210_UFSTAT_RXMASK, \ @@ -2777,6 +2804,9 @@ static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = { .has_fracval = 1, \ } \ +#define EXYNOS_COMMON_SERIAL_DRV_DATA \ + EXYNOS_COMMON_SERIAL_DRV_DATA_USI(0) + static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = { EXYNOS_COMMON_SERIAL_DRV_DATA, .fifosize = { 256, 64, 16, 16 }, |