139 lines
3.3 KiB
C
139 lines
3.3 KiB
C
/*
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* Copyright (C) 2012-2015 Panasonic Corporation
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* Copyright (C) 2015-2016 Socionext Inc.
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* Author: Masahiro Yamada <yamada.masahiro@socionext.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <linux/io.h>
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#include <linux/serial_reg.h>
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#include <linux/sizes.h>
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#include <linux/errno.h>
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#include <dm/device.h>
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#include <serial.h>
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#include <fdtdec.h>
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/*
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* Note: Register map is slightly different from that of 16550.
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*/
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struct uniphier_serial {
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u32 rx; /* In: Receive buffer */
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#define tx rx /* Out: Transmit buffer */
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u32 ier; /* Interrupt Enable Register */
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u32 iir; /* In: Interrupt ID Register */
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u32 char_fcr; /* Charactor / FIFO Control Register */
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u32 lcr_mcr; /* Line/Modem Control Register */
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#define LCR_SHIFT 8
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#define LCR_MASK (0xff << (LCR_SHIFT))
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u32 lsr; /* In: Line Status Register */
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u32 msr; /* In: Modem Status Register */
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u32 __rsv0;
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u32 __rsv1;
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u32 dlr; /* Divisor Latch Register */
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};
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struct uniphier_serial_private_data {
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struct uniphier_serial __iomem *membase;
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unsigned int uartclk;
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};
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#define uniphier_serial_port(dev) \
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((struct uniphier_serial_private_data *)dev_get_priv(dev))->membase
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static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
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{
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struct uniphier_serial_private_data *priv = dev_get_priv(dev);
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struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
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const unsigned int mode_x_div = 16;
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unsigned int divisor;
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divisor = DIV_ROUND_CLOSEST(priv->uartclk, mode_x_div * baudrate);
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writel(divisor, &port->dlr);
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return 0;
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}
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static int uniphier_serial_getc(struct udevice *dev)
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{
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struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
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if (!(readl(&port->lsr) & UART_LSR_DR))
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return -EAGAIN;
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return readl(&port->rx);
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}
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static int uniphier_serial_putc(struct udevice *dev, const char c)
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{
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struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
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if (!(readl(&port->lsr) & UART_LSR_THRE))
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return -EAGAIN;
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writel(c, &port->tx);
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return 0;
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}
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static int uniphier_serial_pending(struct udevice *dev, bool input)
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{
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struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
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if (input)
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return readl(&port->lsr) & UART_LSR_DR;
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else
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return !(readl(&port->lsr) & UART_LSR_THRE);
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}
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static int uniphier_serial_probe(struct udevice *dev)
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{
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DECLARE_GLOBAL_DATA_PTR;
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struct uniphier_serial_private_data *priv = dev_get_priv(dev);
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struct uniphier_serial __iomem *port;
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fdt_addr_t base;
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u32 tmp;
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base = dev_get_addr(dev);
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if (base == FDT_ADDR_T_NONE)
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return -EINVAL;
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port = devm_ioremap(dev, base, SZ_64);
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if (!port)
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return -ENOMEM;
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priv->membase = port;
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priv->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
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"clock-frequency", 0);
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tmp = readl(&port->lcr_mcr);
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tmp &= ~LCR_MASK;
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tmp |= UART_LCR_WLEN8 << LCR_SHIFT;
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writel(tmp, &port->lcr_mcr);
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return 0;
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}
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static const struct udevice_id uniphier_uart_of_match[] = {
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{ .compatible = "socionext,uniphier-uart" },
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{ /* sentinel */ }
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};
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static const struct dm_serial_ops uniphier_serial_ops = {
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.setbrg = uniphier_serial_setbrg,
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.getc = uniphier_serial_getc,
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.putc = uniphier_serial_putc,
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.pending = uniphier_serial_pending,
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};
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U_BOOT_DRIVER(uniphier_serial) = {
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.name = "uniphier-uart",
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.id = UCLASS_SERIAL,
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.of_match = uniphier_uart_of_match,
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.probe = uniphier_serial_probe,
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.priv_auto_alloc_size = sizeof(struct uniphier_serial_private_data),
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.ops = &uniphier_serial_ops,
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};
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