git.sur5r.net Git - u-boot/blob - drivers/serial/atmel_usart.c

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   3  *
   4  * Modified to support C structur SoC access by
   5  * Andreas Bießmann <biessmann@corscience.de>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <errno.h>
  12 #include <watchdog.h>
  13 #include <serial.h>
  14 #include <debug_uart.h>
  15 #include <linux/compiler.h>
  16
  17 #include <asm/io.h>
  18 #ifdef CONFIG_DM_SERIAL
  19 #include <asm/arch/atmel_serial.h>
  20 #endif
  21 #include <asm/arch/clk.h>
  22 #include <asm/arch/hardware.h>
  23
  24 #include "atmel_usart.h"
  25
  26 DECLARE_GLOBAL_DATA_PTR;
  27
  28 static void atmel_serial_setbrg_internal(atmel_usart3_t *usart, int id,
  29                                          int baudrate)
  30 {
  31         unsigned long divisor;
  32         unsigned long usart_hz;
  33
  34         /*
  35          *              Master Clock
  36          * Baud Rate = --------------
  37          *                16 * CD
  38          */
  39         usart_hz = get_usart_clk_rate(id);
  40         divisor = (usart_hz / 16 + baudrate / 2) / baudrate;
  41         writel(USART3_BF(CD, divisor), &usart->brgr);
  42 }
  43
  44 static void atmel_serial_init_internal(atmel_usart3_t *usart)
  45 {
  46         /*
  47          * Just in case: drain transmitter register
  48          * 1000us is enough for baudrate >= 9600
  49          */
  50         if (!(readl(&usart->csr) & USART3_BIT(TXEMPTY)))
  51                 __udelay(1000);
  52
  53         writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
  54 }
  55
  56 static void atmel_serial_activate(atmel_usart3_t *usart)
  57 {
  58         writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
  59                            | USART3_BF(USCLKS, USART3_USCLKS_MCK)
  60                            | USART3_BF(CHRL, USART3_CHRL_8)
  61                            | USART3_BF(PAR, USART3_PAR_NONE)
  62                            | USART3_BF(NBSTOP, USART3_NBSTOP_1)),
  63                            &usart->mr);
  64         writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
  65         /* 100us is enough for the new settings to be settled */
  66         __udelay(100);
  67 }
  68
  69 #ifndef CONFIG_DM_SERIAL
  70 static void atmel_serial_setbrg(void)
  71 {
  72         atmel_serial_setbrg_internal((atmel_usart3_t *)CONFIG_USART_BASE,
  73                                      CONFIG_USART_ID, gd->baudrate);
  74 }
  75
  76 static int atmel_serial_init(void)
  77 {
  78         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  79
  80         atmel_serial_init_internal(usart);
  81         serial_setbrg();
  82         atmel_serial_activate(usart);
  83
  84         return 0;
  85 }
  86
  87 static void atmel_serial_putc(char c)
  88 {
  89         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  90
  91         if (c == '\n')
  92                 serial_putc('\r');
  93
  94         while (!(readl(&usart->csr) & USART3_BIT(TXRDY)));
  95         writel(c, &usart->thr);
  96 }
  97
  98 static int atmel_serial_getc(void)
  99 {
 100         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 101
 102         while (!(readl(&usart->csr) & USART3_BIT(RXRDY)))
 103                  WATCHDOG_RESET();
 104         return readl(&usart->rhr);
 105 }
 106
 107 static int atmel_serial_tstc(void)
 108 {
 109         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
 110         return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0;
 111 }
 112
 113 static struct serial_device atmel_serial_drv = {
 114         .name   = "atmel_serial",
 115         .start  = atmel_serial_init,
 116         .stop   = NULL,
 117         .setbrg = atmel_serial_setbrg,
 118         .putc   = atmel_serial_putc,
 119         .puts   = default_serial_puts,
 120         .getc   = atmel_serial_getc,
 121         .tstc   = atmel_serial_tstc,
 122 };
 123
 124 void atmel_serial_initialize(void)
 125 {
 126         serial_register(&atmel_serial_drv);
 127 }
 128
 129 __weak struct serial_device *default_serial_console(void)
 130 {
 131         return &atmel_serial_drv;
 132 }
 133 #endif
 134
 135 #ifdef CONFIG_DM_SERIAL
 136
 137 struct atmel_serial_priv {
 138         atmel_usart3_t *usart;
 139 };
 140
 141 int atmel_serial_setbrg(struct udevice *dev, int baudrate)
 142 {
 143         struct atmel_serial_priv *priv = dev_get_priv(dev);
 144
 145         atmel_serial_setbrg_internal(priv->usart, 0 /* ignored */, baudrate);
 146         atmel_serial_activate(priv->usart);
 147
 148         return 0;
 149 }
 150
 151 static int atmel_serial_getc(struct udevice *dev)
 152 {
 153         struct atmel_serial_priv *priv = dev_get_priv(dev);
 154
 155         if (!(readl(&priv->usart->csr) & USART3_BIT(RXRDY)))
 156                 return -EAGAIN;
 157
 158         return readl(&priv->usart->rhr);
 159 }
 160
 161 static int atmel_serial_putc(struct udevice *dev, const char ch)
 162 {
 163         struct atmel_serial_priv *priv = dev_get_priv(dev);
 164
 165         if (!(readl(&priv->usart->csr) & USART3_BIT(TXRDY)))
 166                 return -EAGAIN;
 167
 168         writel(ch, &priv->usart->thr);
 169
 170         return 0;
 171 }
 172
 173 static int atmel_serial_pending(struct udevice *dev, bool input)
 174 {
 175         struct atmel_serial_priv *priv = dev_get_priv(dev);
 176         uint32_t csr = readl(&priv->usart->csr);
 177
 178         if (input)
 179                 return csr & USART3_BIT(RXRDY) ? 1 : 0;
 180         else
 181                 return csr & USART3_BIT(TXEMPTY) ? 0 : 1;
 182 }
 183
 184 static const struct dm_serial_ops atmel_serial_ops = {
 185         .putc = atmel_serial_putc,
 186         .pending = atmel_serial_pending,
 187         .getc = atmel_serial_getc,
 188         .setbrg = atmel_serial_setbrg,
 189 };
 190
 191 static int atmel_serial_probe(struct udevice *dev)
 192 {
 193         struct atmel_serial_platdata *plat = dev->platdata;
 194         struct atmel_serial_priv *priv = dev_get_priv(dev);
 195 #if CONFIG_IS_ENABLED(OF_CONTROL)
 196         fdt_addr_t addr_base;
 197
 198         addr_base = dev_get_addr(dev);
 199         if (addr_base == FDT_ADDR_T_NONE)
 200                 return -ENODEV;
 201
 202         plat->base_addr = (uint32_t)addr_base;
 203 #endif
 204         priv->usart = (atmel_usart3_t *)plat->base_addr;
 205         atmel_serial_init_internal(priv->usart);
 206
 207         return 0;
 208 }
 209
 210 #if CONFIG_IS_ENABLED(OF_CONTROL)
 211 static const struct udevice_id atmel_serial_ids[] = {
 212         { .compatible = "atmel,at91sam9260-usart" },
 213         { }
 214 };
 215 #endif
 216
 217 U_BOOT_DRIVER(serial_atmel) = {
 218         .name   = "serial_atmel",
 219         .id     = UCLASS_SERIAL,
 220 #if CONFIG_IS_ENABLED(OF_CONTROL)
 221         .of_match = atmel_serial_ids,
 222         .platdata_auto_alloc_size = sizeof(struct atmel_serial_platdata),
 223 #endif
 224         .probe = atmel_serial_probe,
 225         .ops    = &atmel_serial_ops,
 226         .flags = DM_FLAG_PRE_RELOC,
 227         .priv_auto_alloc_size   = sizeof(struct atmel_serial_priv),
 228 };
 229 #endif
 230
 231 #ifdef CONFIG_DEBUG_UART_ATMEL
 232 static inline void _debug_uart_init(void)
 233 {
 234         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_DEBUG_UART_BASE;
 235
 236         atmel_serial_setbrg_internal(usart, 0, CONFIG_BAUDRATE);
 237 }
 238
 239 static inline void _debug_uart_putc(int ch)
 240 {
 241         atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_DEBUG_UART_BASE;
 242
 243         while (!(readl(&usart->csr) & USART3_BIT(TXRDY)))
 244                 ;
 245
 246         writel(ch, &usart->thr);
 247 }
 248
 249 DEBUG_UART_FUNCS
 250 #endif