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

   1 /*
   2  * Copyright (C) 2012-2015 Panasonic Corporation
   3  *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <linux/serial_reg.h>
   9 #include <asm/io.h>
  10 #include <asm/errno.h>
  11 #include <dm/device.h>
  12 #include <dm/platform_data/serial-uniphier.h>
  13 #include <serial.h>
  14 #include <fdtdec.h>
  15
  16 /*
  17  * Note: Register map is slightly different from that of 16550.
  18  */
  19 struct uniphier_serial {
  20         u32 rx;                 /* In:  Receive buffer */
  21 #define tx rx                   /* Out: Transmit buffer */
  22         u32 ier;                /* Interrupt Enable Register */
  23         u32 iir;                /* In: Interrupt ID Register */
  24         u32 char_fcr;           /* Charactor / FIFO Control Register */
  25         u32 lcr_mcr;            /* Line/Modem Control Register */
  26 #define LCR_SHIFT       8
  27 #define LCR_MASK        (0xff << (LCR_SHIFT))
  28         u32 lsr;                /* In: Line Status Register */
  29         u32 msr;                /* In: Modem Status Register */
  30         u32 __rsv0;
  31         u32 __rsv1;
  32         u32 dlr;                /* Divisor Latch Register */
  33 };
  34
  35 struct uniphier_serial_private_data {
  36         struct uniphier_serial __iomem *membase;
  37 };
  38
  39 #define uniphier_serial_port(dev)       \
  40         ((struct uniphier_serial_private_data *)dev_get_priv(dev))->membase
  41
  42 static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
  43 {
  44         struct uniphier_serial_platform_data *plat = dev_get_platdata(dev);
  45         struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
  46         const unsigned int mode_x_div = 16;
  47         unsigned int divisor;
  48         u32 tmp;
  49
  50         tmp = readl(&port->lcr_mcr);
  51         tmp &= ~LCR_MASK;
  52         tmp |= UART_LCR_WLEN8 << LCR_SHIFT;
  53         writel(tmp, &port->lcr_mcr);
  54
  55         divisor = DIV_ROUND_CLOSEST(plat->uartclk, mode_x_div * baudrate);
  56
  57         writel(divisor, &port->dlr);
  58
  59         return 0;
  60 }
  61
  62 static int uniphier_serial_getc(struct udevice *dev)
  63 {
  64         struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
  65
  66         if (!(readl(&port->lsr) & UART_LSR_DR))
  67                 return -EAGAIN;
  68
  69         return readl(&port->rx);
  70 }
  71
  72 static int uniphier_serial_putc(struct udevice *dev, const char c)
  73 {
  74         struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
  75
  76         if (!(readl(&port->lsr) & UART_LSR_THRE))
  77                 return -EAGAIN;
  78
  79         writel(c, &port->tx);
  80
  81         return 0;
  82 }
  83
  84 static int uniphier_serial_pending(struct udevice *dev, bool input)
  85 {
  86         struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
  87
  88         if (input)
  89                 return readl(&port->lsr) & UART_LSR_DR;
  90         else
  91                 return !(readl(&port->lsr) & UART_LSR_THRE);
  92 }
  93
  94 static int uniphier_serial_probe(struct udevice *dev)
  95 {
  96         struct uniphier_serial_private_data *priv = dev_get_priv(dev);
  97         struct uniphier_serial_platform_data *plat = dev_get_platdata(dev);
  98
  99         priv->membase = map_sysmem(plat->base, sizeof(struct uniphier_serial));
 100
 101         if (!priv->membase)
 102                 return -ENOMEM;
 103
 104         return 0;
 105 }
 106
 107 static int uniphier_serial_remove(struct udevice *dev)
 108 {
 109         unmap_sysmem(uniphier_serial_port(dev));
 110
 111         return 0;
 112 }
 113
 114 #ifdef CONFIG_OF_CONTROL
 115 static const struct udevice_id uniphier_uart_of_match[] = {
 116         { .compatible = "panasonic,uniphier-uart" },
 117         {},
 118 };
 119
 120 static int uniphier_serial_ofdata_to_platdata(struct udevice *dev)
 121 {
 122         struct uniphier_serial_platform_data *plat = dev_get_platdata(dev);
 123         DECLARE_GLOBAL_DATA_PTR;
 124
 125         plat->base = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
 126         plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 127                                        "clock-frequency", 0);
 128
 129         return 0;
 130 }
 131 #endif
 132
 133 static const struct dm_serial_ops uniphier_serial_ops = {
 134         .setbrg = uniphier_serial_setbrg,
 135         .getc = uniphier_serial_getc,
 136         .putc = uniphier_serial_putc,
 137         .pending = uniphier_serial_pending,
 138 };
 139
 140 U_BOOT_DRIVER(uniphier_serial) = {
 141         .name = DRIVER_NAME,
 142         .id = UCLASS_SERIAL,
 143         .of_match = of_match_ptr(uniphier_uart_of_match),
 144         .ofdata_to_platdata = of_match_ptr(uniphier_serial_ofdata_to_platdata),
 145         .probe = uniphier_serial_probe,
 146         .remove = uniphier_serial_remove,
 147         .priv_auto_alloc_size = sizeof(struct uniphier_serial_private_data),
 148         .platdata_auto_alloc_size =
 149                                 sizeof(struct uniphier_serial_platform_data),
 150         .ops = &uniphier_serial_ops,
 151         .flags = DM_FLAG_PRE_RELOC,
 152 };