2 * Copyright (C) 2012-2015 Panasonic Corporation
3 * Copyright (C) 2015-2016 Socionext Inc.
4 * Author: Masahiro Yamada <yamada.masahiro@socionext.com>
6 * SPDX-License-Identifier: GPL-2.0+
12 #include <linux/serial_reg.h>
13 #include <linux/sizes.h>
14 #include <linux/errno.h>
19 * Note: Register map is slightly different from that of 16550.
21 struct uniphier_serial {
22 u32 rx; /* In: Receive buffer */
23 #define tx rx /* Out: Transmit buffer */
24 u32 ier; /* Interrupt Enable Register */
25 u32 iir; /* In: Interrupt ID Register */
26 u32 char_fcr; /* Charactor / FIFO Control Register */
27 u32 lcr_mcr; /* Line/Modem Control Register */
29 #define LCR_MASK (0xff << (LCR_SHIFT))
30 u32 lsr; /* In: Line Status Register */
31 u32 msr; /* In: Modem Status Register */
34 u32 dlr; /* Divisor Latch Register */
37 struct uniphier_serial_private_data {
38 struct uniphier_serial __iomem *membase;
42 #define uniphier_serial_port(dev) \
43 ((struct uniphier_serial_private_data *)dev_get_priv(dev))->membase
45 static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
47 struct uniphier_serial_private_data *priv = dev_get_priv(dev);
48 struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
49 const unsigned int mode_x_div = 16;
52 divisor = DIV_ROUND_CLOSEST(priv->uartclk, mode_x_div * baudrate);
54 writel(divisor, &port->dlr);
59 static int uniphier_serial_getc(struct udevice *dev)
61 struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
63 if (!(readl(&port->lsr) & UART_LSR_DR))
66 return readl(&port->rx);
69 static int uniphier_serial_putc(struct udevice *dev, const char c)
71 struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
73 if (!(readl(&port->lsr) & UART_LSR_THRE))
81 static int uniphier_serial_pending(struct udevice *dev, bool input)
83 struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
86 return readl(&port->lsr) & UART_LSR_DR;
88 return !(readl(&port->lsr) & UART_LSR_THRE);
91 static int uniphier_serial_probe(struct udevice *dev)
93 DECLARE_GLOBAL_DATA_PTR;
94 struct uniphier_serial_private_data *priv = dev_get_priv(dev);
95 struct uniphier_serial __iomem *port;
99 base = devfdt_get_addr(dev);
100 if (base == FDT_ADDR_T_NONE)
103 port = devm_ioremap(dev, base, SZ_64);
107 priv->membase = port;
109 priv->uartclk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
110 "clock-frequency", 0);
112 tmp = readl(&port->lcr_mcr);
114 tmp |= UART_LCR_WLEN8 << LCR_SHIFT;
115 writel(tmp, &port->lcr_mcr);
120 static const struct udevice_id uniphier_uart_of_match[] = {
121 { .compatible = "socionext,uniphier-uart" },
125 static const struct dm_serial_ops uniphier_serial_ops = {
126 .setbrg = uniphier_serial_setbrg,
127 .getc = uniphier_serial_getc,
128 .putc = uniphier_serial_putc,
129 .pending = uniphier_serial_pending,
132 U_BOOT_DRIVER(uniphier_serial) = {
133 .name = "uniphier-uart",
135 .of_match = uniphier_uart_of_match,
136 .probe = uniphier_serial_probe,
137 .priv_auto_alloc_size = sizeof(struct uniphier_serial_private_data),
138 .ops = &uniphier_serial_ops,