diff options
Diffstat (limited to 'drivers/serial/serial_imx.c')
| -rw-r--r-- | drivers/serial/serial_imx.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/serial/serial_imx.c b/drivers/serial/serial_imx.c new file mode 100644 index 0000000..b9ca748 --- /dev/null +++ b/drivers/serial/serial_imx.c @@ -0,0 +1,221 @@ +/* + * (c) 2004 Sascha Hauer <sascha@saschahauer.de> + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <common.h> +#include <asm/arch/imx-regs.h> + +#if defined CONFIG_IMX_SERIAL1 +#define UART_BASE IMX_UART1_BASE +#elif defined CONFIG_IMX_SERIAL2 +#define UART_BASE IMX_UART2_BASE +#else +#error "define CONFIG_IMX_SERIAL1, CONFIG_IMX_SERIAL2 or CONFIG_IMX_SERIAL_NONE" +#endif + +struct imx_serial { + volatile uint32_t urxd[16]; + volatile uint32_t utxd[16]; + volatile uint32_t ucr1; + volatile uint32_t ucr2; + volatile uint32_t ucr3; + volatile uint32_t ucr4; + volatile uint32_t ufcr; + volatile uint32_t usr1; + volatile uint32_t usr2; + volatile uint32_t uesc; + volatile uint32_t utim; + volatile uint32_t ubir; + volatile uint32_t ubmr; + volatile uint32_t ubrc; + volatile uint32_t bipr[4]; + volatile uint32_t bmpr[4]; + volatile uint32_t uts; +}; + +DECLARE_GLOBAL_DATA_PTR; + +void serial_setbrg (void) +{ + serial_init(); +} + +extern void imx_gpio_mode(int gpio_mode); + +/* + * Initialise the serial port with the given baudrate. The settings + * are always 8 data bits, no parity, 1 stop bit, no start bits. + * + */ +int serial_init (void) +{ + volatile struct imx_serial* base = (struct imx_serial *)UART_BASE; + unsigned int ufcr_rfdiv; + unsigned int refclk; + +#ifdef CONFIG_IMX_SERIAL1 + imx_gpio_mode(PC11_PF_UART1_TXD); + imx_gpio_mode(PC12_PF_UART1_RXD); +#else + imx_gpio_mode(PB30_PF_UART2_TXD); + imx_gpio_mode(PB31_PF_UART2_RXD); +#endif + + /* Disable UART */ + base->ucr1 &= ~UCR1_UARTEN; + + /* Set to default POR state */ + + base->ucr1 = 0x00000004; + base->ucr2 = 0x00000000; + base->ucr3 = 0x00000000; + base->ucr4 = 0x00008040; + base->uesc = 0x0000002B; + base->utim = 0x00000000; + base->ubir = 0x00000000; + base->ubmr = 0x00000000; + base->uts = 0x00000000; + /* Set clocks */ + base->ucr4 |= UCR4_REF16; + + /* Configure FIFOs */ + base->ufcr = 0xa81; + + /* set the baud rate. + * + * baud * 16 x + * --------- = - + * refclk y + * + * x - 1 = UBIR + * y - 1 = UBMR + * + * each register is 16 bits wide. refclk max is 96 MHz + * + */ + + ufcr_rfdiv = ((base->ufcr) & UFCR_RFDIV) >> 7; + if (ufcr_rfdiv == 6) + ufcr_rfdiv = 7; + else + ufcr_rfdiv = 6 - ufcr_rfdiv; + + refclk = get_PERCLK1(); + refclk /= ufcr_rfdiv; + + /* Set the numerator value minus one of the BRM ratio */ + base->ubir = (gd->baudrate / 100) - 1; + + /* Set the denominator value minus one of the BRM ratio */ + base->ubmr = (refclk/(16 * 100)) - 1; + + /* Set to 8N1 */ + base->ucr2 &= ~UCR2_PREN; + base->ucr2 |= UCR2_WS; + base->ucr2 &= ~UCR2_STPB; + + /* Ignore RTS */ + base->ucr2 |= UCR2_IRTS; + + /* Enable UART */ + base->ucr1 |= UCR1_UARTEN | UCR1_UARTCLKEN; + + /* Enable FIFOs */ + base->ucr2 |= UCR2_SRST | UCR2_RXEN | UCR2_TXEN; + + /* Clear status flags */ + base->usr2 |= USR2_ADET | + USR2_DTRF | + USR2_IDLE | + USR2_IRINT | + USR2_WAKE | + USR2_RTSF | + USR2_BRCD | + USR2_ORE; + + /* Clear status flags */ + base->usr1 |= USR1_PARITYERR | + USR1_RTSD | + USR1_ESCF | + USR1_FRAMERR | + USR1_AIRINT | + USR1_AWAKE; + return (0); +} + +/* + * Read a single byte from the serial port. Returns 1 on success, 0 + * otherwise. When the function is successful, the character read is + * written into its argument c. + */ +int serial_getc (void) +{ + volatile struct imx_serial* base = (struct imx_serial *)UART_BASE; + unsigned char ch; + + while(base->uts & UTS_RXEMPTY); + + ch = (char)base->urxd[0]; + + return ch; +} + +#ifdef CONFIG_HWFLOW +static int hwflow = 0; /* turned off by default */ +int hwflow_onoff(int on) +{ +} +#endif + +/* + * Output a single byte to the serial port. + */ +void serial_putc (const char c) +{ + volatile struct imx_serial* base = (struct imx_serial *)UART_BASE; + + /* Wait for Tx FIFO not full */ + while (base->uts & UTS_TXFULL); + + base->utxd[0] = c; + + /* If \n, also do \r */ + if (c == '\n') + serial_putc ('\r'); +} + +/* + * Test whether a character is in the RX buffer + */ +int serial_tstc (void) +{ + volatile struct imx_serial* base = (struct imx_serial *)UART_BASE; + + /* If receive fifo is empty, return false */ + if (base->uts & UTS_RXEMPTY) + return 0; + return 1; +} + +void +serial_puts (const char *s) +{ + while (*s) { + serial_putc (*s++); + } +} |