cpu/arm920t/imx/serial.c

   1 /*
   2  * (c) 2004 Sascha Hauer <sascha@saschahauer.de>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  *
  18  */
  19
  20 #include <common.h>
  21 #if defined (CONFIG_IMX)
  22
  23 #include <asm/arch/imx-regs.h>
  24
  25 #ifndef CONFIG_IMX_SERIAL_NONE
  26
  27 #if defined CONFIG_IMX_SERIAL1
  28 #define UART_BASE IMX_UART1_BASE
  29 #elif defined CONFIG_IMX_SERIAL2
  30 #define UART_BASE IMX_UART2_BASE
  31 #else
  32 #error "define CONFIG_IMX_SERIAL1, CONFIG_IMX_SERIAL2 or CONFIG_IMX_SERIAL_NONE"
  33 #endif
  34
  35 struct imx_serial {
  36         volatile uint32_t urxd[16];
  37         volatile uint32_t utxd[16];
  38         volatile uint32_t ucr1;
  39         volatile uint32_t ucr2;
  40         volatile uint32_t ucr3;
  41         volatile uint32_t ucr4;
  42         volatile uint32_t ufcr;
  43         volatile uint32_t usr1;
  44         volatile uint32_t usr2;
  45         volatile uint32_t uesc;
  46         volatile uint32_t utim;
  47         volatile uint32_t ubir;
  48         volatile uint32_t ubmr;
  49         volatile uint32_t ubrc;
  50         volatile uint32_t bipr[4];
  51         volatile uint32_t bmpr[4];
  52         volatile uint32_t uts;
  53 };
  54
  55 void serial_setbrg (void)
  56 {
  57         serial_init();
  58 }
  59
  60 extern void imx_gpio_mode(int gpio_mode);
  61
  62 /*
  63  * Initialise the serial port with the given baudrate. The settings
  64  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  65  *
  66  */
  67 int serial_init (void)
  68 {
  69         volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
  70 #ifdef CONFIG_IMX_SERIAL1
  71         imx_gpio_mode(PC11_PF_UART1_TXD);
  72         imx_gpio_mode(PC12_PF_UART1_RXD);
  73 #else
  74         imx_gpio_mode(PB30_PF_UART2_TXD);
  75         imx_gpio_mode(PB31_PF_UART2_RXD);
  76 #endif
  77
  78         /* Disable UART */
  79         base->ucr1 &= ~UCR1_UARTEN;
  80
  81         /* Set to default POR state */
  82
  83         base->ucr1 = 0x00000004;
  84         base->ucr2 = 0x00000000;
  85         base->ucr3 = 0x00000000;
  86         base->ucr4 = 0x00008040;
  87         base->uesc = 0x0000002B;
  88         base->utim = 0x00000000;
  89         base->ubir = 0x00000000;
  90         base->ubmr = 0x00000000;
  91         base->uts  = 0x00000000;
  92         /* Set clocks */
  93         base->ucr4 |= UCR4_REF16;
  94
  95         /* Configure FIFOs */
  96         base->ufcr = 0xa81;
  97
  98         /* Set the numerator value minus one of the BRM ratio */
  99         base->ubir = (CONFIG_BAUDRATE / 100) - 1;
 100
 101         /* Set the denominator value minus one of the BRM ratio */
 102         base->ubmr = 10000 - 1;
 103
 104         /* Set to 8N1 */
 105         base->ucr2 &= ~UCR2_PREN;
 106         base->ucr2 |= UCR2_WS;
 107         base->ucr2 &= ~UCR2_STPB;
 108
 109         /* Ignore RTS */
 110         base->ucr2 |= UCR2_IRTS;
 111
 112         /* Enable UART */
 113         base->ucr1 |= UCR1_UARTEN | UCR1_UARTCLKEN;
 114
 115         /* Enable FIFOs */
 116         base->ucr2 |= UCR2_SRST | UCR2_RXEN | UCR2_TXEN;
 117
 118         /* Clear status flags */
 119         base->usr2 |= USR2_ADET  |
 120                   USR2_DTRF  |
 121                   USR2_IDLE  |
 122                   USR2_IRINT |
 123                   USR2_WAKE  |
 124                   USR2_RTSF  |
 125                   USR2_BRCD  |
 126                   USR2_ORE   |
 127                   USR2_RDR;
 128
 129         /* Clear status flags */
 130         base->usr1 |= USR1_PARITYERR |
 131                   USR1_RTSD      |
 132                   USR1_ESCF      |
 133                   USR1_FRAMERR   |
 134                   USR1_AIRINT    |
 135                   USR1_AWAKE;
 136         return (0);
 137 }
 138
 139 /*
 140  * Read a single byte from the serial port. Returns 1 on success, 0
 141  * otherwise. When the function is successful, the character read is
 142  * written into its argument c.
 143  */
 144 int serial_getc (void)
 145 {
 146         volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
 147         unsigned char ch;
 148
 149         while(base->uts & UTS_RXEMPTY);
 150
 151         ch = (char)base->urxd[0];
 152
 153         return ch;
 154 }
 155
 156 #ifdef CONFIG_HWFLOW
 157 static int hwflow = 0; /* turned off by default */
 158 int hwflow_onoff(int on)
 159 {
 160 }
 161 #endif
 162
 163 /*
 164  * Output a single byte to the serial port.
 165  */
 166 void serial_putc (const char c)
 167 {
 168         volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
 169
 170         /* Wait for Tx FIFO not full */
 171         while (base->uts & UTS_TXFULL);
 172
 173         base->utxd[0] = c;
 174
 175         /* If \n, also do \r */
 176         if (c == '\n')
 177                 serial_putc ('\r');
 178 }
 179
 180 /*
 181  * Test whether a character is in the RX buffer
 182  */
 183 int serial_tstc (void)
 184 {
 185         volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
 186
 187         /* If receive fifo is empty, return false */
 188         if (base->uts & UTS_RXEMPTY)
 189                 return 0;
 190         return 1;
 191 }
 192
 193 void
 194 serial_puts (const char *s)
 195 {
 196         while (*s) {
 197                 serial_putc (*s++);
 198         }
 199 }
 200 #endif /* CONFIG_IMX_SERIAL_NONE */
 201 #endif /* defined CONFIG_IMX */