linux/arch/arm/mach-omap1/serial.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * linux/arch/arm/mach-omap1/serial.c
   4 *
   5 * OMAP1 serial support.
   6 */
   7#include <linux/gpio.h>
   8#include <linux/module.h>
   9#include <linux/kernel.h>
  10#include <linux/init.h>
  11#include <linux/irq.h>
  12#include <linux/delay.h>
  13#include <linux/serial.h>
  14#include <linux/tty.h>
  15#include <linux/serial_8250.h>
  16#include <linux/serial_reg.h>
  17#include <linux/clk.h>
  18#include <linux/io.h>
  19
  20#include <asm/mach-types.h>
  21
  22#include <mach/mux.h>
  23
  24#include "pm.h"
  25#include "soc.h"
  26
  27static struct clk * uart1_ck;
  28static struct clk * uart2_ck;
  29static struct clk * uart3_ck;
  30
  31static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
  32                                          int offset)
  33{
  34        offset <<= up->regshift;
  35        return (unsigned int)__raw_readb(up->membase + offset);
  36}
  37
  38static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
  39                                    int value)
  40{
  41        offset <<= p->regshift;
  42        __raw_writeb(value, p->membase + offset);
  43}
  44
  45/*
  46 * Internal UARTs need to be initialized for the 8250 autoconfig to work
  47 * properly. Note that the TX watermark initialization may not be needed
  48 * once the 8250.c watermark handling code is merged.
  49 */
  50static void __init omap_serial_reset(struct plat_serial8250_port *p)
  51{
  52        omap_serial_outp(p, UART_OMAP_MDR1,
  53                        UART_OMAP_MDR1_DISABLE);        /* disable UART */
  54        omap_serial_outp(p, UART_OMAP_SCR, 0x08);       /* TX watermark */
  55        omap_serial_outp(p, UART_OMAP_MDR1,
  56                        UART_OMAP_MDR1_16X_MODE);       /* enable UART */
  57
  58        if (!cpu_is_omap15xx()) {
  59                omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
  60                while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
  61        }
  62}
  63
  64static struct plat_serial8250_port serial_platform_data[] = {
  65        {
  66                .mapbase        = OMAP1_UART1_BASE,
  67                .irq            = INT_UART1,
  68                .flags          = UPF_BOOT_AUTOCONF,
  69                .iotype         = UPIO_MEM,
  70                .regshift       = 2,
  71                .uartclk        = OMAP16XX_BASE_BAUD * 16,
  72        },
  73        {
  74                .mapbase        = OMAP1_UART2_BASE,
  75                .irq            = INT_UART2,
  76                .flags          = UPF_BOOT_AUTOCONF,
  77                .iotype         = UPIO_MEM,
  78                .regshift       = 2,
  79                .uartclk        = OMAP16XX_BASE_BAUD * 16,
  80        },
  81        {
  82                .mapbase        = OMAP1_UART3_BASE,
  83                .irq            = INT_UART3,
  84                .flags          = UPF_BOOT_AUTOCONF,
  85                .iotype         = UPIO_MEM,
  86                .regshift       = 2,
  87                .uartclk        = OMAP16XX_BASE_BAUD * 16,
  88        },
  89        { },
  90};
  91
  92static struct platform_device serial_device = {
  93        .name                   = "serial8250",
  94        .id                     = PLAT8250_DEV_PLATFORM,
  95        .dev                    = {
  96                .platform_data  = serial_platform_data,
  97        },
  98};
  99
 100/*
 101 * Note that on Innovator-1510 UART2 pins conflict with USB2.
 102 * By default UART2 does not work on Innovator-1510 if you have
 103 * USB OHCI enabled. To use UART2, you must disable USB2 first.
 104 */
 105void __init omap_serial_init(void)
 106{
 107        int i;
 108
 109        if (cpu_is_omap7xx()) {
 110                serial_platform_data[0].regshift = 0;
 111                serial_platform_data[1].regshift = 0;
 112                serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
 113                serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
 114        }
 115
 116        if (cpu_is_omap15xx()) {
 117                serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
 118                serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
 119                serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
 120        }
 121
 122        for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {
 123
 124                /* Don't look at UARTs higher than 2 for omap7xx */
 125                if (cpu_is_omap7xx() && i > 1) {
 126                        serial_platform_data[i].membase = NULL;
 127                        serial_platform_data[i].mapbase = 0;
 128                        continue;
 129                }
 130
 131                /* Static mapping, never released */
 132                serial_platform_data[i].membase =
 133                        ioremap(serial_platform_data[i].mapbase, SZ_2K);
 134                if (!serial_platform_data[i].membase) {
 135                        printk(KERN_ERR "Could not ioremap uart%i\n", i);
 136                        continue;
 137                }
 138                switch (i) {
 139                case 0:
 140                        uart1_ck = clk_get(NULL, "uart1_ck");
 141                        if (IS_ERR(uart1_ck))
 142                                printk("Could not get uart1_ck\n");
 143                        else {
 144                                clk_enable(uart1_ck);
 145                                if (cpu_is_omap15xx())
 146                                        clk_set_rate(uart1_ck, 12000000);
 147                        }
 148                        break;
 149                case 1:
 150                        uart2_ck = clk_get(NULL, "uart2_ck");
 151                        if (IS_ERR(uart2_ck))
 152                                printk("Could not get uart2_ck\n");
 153                        else {
 154                                clk_enable(uart2_ck);
 155                                if (cpu_is_omap15xx())
 156                                        clk_set_rate(uart2_ck, 12000000);
 157                                else
 158                                        clk_set_rate(uart2_ck, 48000000);
 159                        }
 160                        break;
 161                case 2:
 162                        uart3_ck = clk_get(NULL, "uart3_ck");
 163                        if (IS_ERR(uart3_ck))
 164                                printk("Could not get uart3_ck\n");
 165                        else {
 166                                clk_enable(uart3_ck);
 167                                if (cpu_is_omap15xx())
 168                                        clk_set_rate(uart3_ck, 12000000);
 169                        }
 170                        break;
 171                }
 172                omap_serial_reset(&serial_platform_data[i]);
 173        }
 174}
 175
 176#ifdef CONFIG_OMAP_SERIAL_WAKE
 177
 178static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
 179{
 180        /* Need to do something with serial port right after wake-up? */
 181        return IRQ_HANDLED;
 182}
 183
 184/*
 185 * Reroutes serial RX lines to GPIO lines for the duration of
 186 * sleep to allow waking up the device from serial port even
 187 * in deep sleep.
 188 */
 189void omap_serial_wake_trigger(int enable)
 190{
 191        if (!cpu_is_omap16xx())
 192                return;
 193
 194        if (uart1_ck != NULL) {
 195                if (enable)
 196                        omap_cfg_reg(V14_16XX_GPIO37);
 197                else
 198                        omap_cfg_reg(V14_16XX_UART1_RX);
 199        }
 200        if (uart2_ck != NULL) {
 201                if (enable)
 202                        omap_cfg_reg(R9_16XX_GPIO18);
 203                else
 204                        omap_cfg_reg(R9_16XX_UART2_RX);
 205        }
 206        if (uart3_ck != NULL) {
 207                if (enable)
 208                        omap_cfg_reg(L14_16XX_GPIO49);
 209                else
 210                        omap_cfg_reg(L14_16XX_UART3_RX);
 211        }
 212}
 213
 214static void __init omap_serial_set_port_wakeup(int gpio_nr)
 215{
 216        int ret;
 217
 218        ret = gpio_request(gpio_nr, "UART wake");
 219        if (ret < 0) {
 220                printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
 221                       gpio_nr);
 222                return;
 223        }
 224        gpio_direction_input(gpio_nr);
 225        ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
 226                          IRQF_TRIGGER_RISING, "serial wakeup", NULL);
 227        if (ret) {
 228                gpio_free(gpio_nr);
 229                printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
 230                       gpio_nr);
 231                return;
 232        }
 233        enable_irq_wake(gpio_to_irq(gpio_nr));
 234}
 235
 236int __init omap_serial_wakeup_init(void)
 237{
 238        if (!cpu_is_omap16xx())
 239                return 0;
 240
 241        if (uart1_ck != NULL)
 242                omap_serial_set_port_wakeup(37);
 243        if (uart2_ck != NULL)
 244                omap_serial_set_port_wakeup(18);
 245        if (uart3_ck != NULL)
 246                omap_serial_set_port_wakeup(49);
 247
 248        return 0;
 249}
 250
 251#endif  /* CONFIG_OMAP_SERIAL_WAKE */
 252
 253static int __init omap_init(void)
 254{
 255        if (!cpu_class_is_omap1())
 256                return -ENODEV;
 257
 258        return platform_device_register(&serial_device);
 259}
 260arch_initcall(omap_init);
 261