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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2012-2015 Panasonic Corporation
* Copyright (C) 2015-2016 Socionext Inc.
* Author: Masahiro Yamada <yamada.masahiro@socionext.com>
*/
#include <common.h>
#include <dm.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <linux/serial_reg.h>
#include <linux/sizes.h>
#include <linux/errno.h>
#include <serial.h>
#include <fdtdec.h>
#define UNIPHIER_UART_REGSHIFT 2
#define UNIPHIER_UART_RX (0 << (UNIPHIER_UART_REGSHIFT))
#define UNIPHIER_UART_TX UNIPHIER_UART_RX
/* bit[15:8] = CHAR, bit[7:0] = FCR */
#define UNIPHIER_UART_CHAR_FCR (3 << (UNIPHIER_UART_REGSHIFT))
#define UNIPHIER_UART_FCR_MASK GENMASK(7, 0)
/* bit[15:8] = LCR, bit[7:0] = MCR */
#define UNIPHIER_UART_LCR_MCR (4 << (UNIPHIER_UART_REGSHIFT))
#define UNIPHIER_UART_LCR_MASK GENMASK(15, 8)
#define UNIPHIER_UART_LSR (5 << (UNIPHIER_UART_REGSHIFT))
/* Divisor Latch Register */
#define UNIPHIER_UART_DLR (9 << (UNIPHIER_UART_REGSHIFT))
struct uniphier_serial_priv {
void __iomem *membase;
unsigned int uartclk;
};
static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
{
struct uniphier_serial_priv *priv = dev_get_priv(dev);
static const unsigned int mode_x_div = 16;
unsigned int divisor;
divisor = DIV_ROUND_CLOSEST(priv->uartclk, mode_x_div * baudrate);
/* flush the trasmitter before changing hw setting */
while (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_TEMT))
;
writel(divisor, priv->membase + UNIPHIER_UART_DLR);
return 0;
}
static int uniphier_serial_getc(struct udevice *dev)
{
struct uniphier_serial_priv *priv = dev_get_priv(dev);
if (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_DR))
return -EAGAIN;
return readl(priv->membase + UNIPHIER_UART_RX);
}
static int uniphier_serial_putc(struct udevice *dev, const char c)
{
struct uniphier_serial_priv *priv = dev_get_priv(dev);
if (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_THRE))
return -EAGAIN;
writel(c, priv->membase + UNIPHIER_UART_TX);
return 0;
}
static int uniphier_serial_pending(struct udevice *dev, bool input)
{
struct uniphier_serial_priv *priv = dev_get_priv(dev);
if (input)
return readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_DR;
else
return !(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_THRE);
}
/*
* SPL does not have enough memory footprint for the clock driver.
* Hardcode clock frequency for each SoC.
*/
struct uniphier_serial_clk_data {
const char *compatible;
unsigned int clk_rate;
};
static const struct uniphier_serial_clk_data uniphier_serial_clk_data[] = {
{ .compatible = "socionext,uniphier-ld4", .clk_rate = 36864000 },
{ .compatible = "socionext,uniphier-pro4", .clk_rate = 73728000 },
{ .compatible = "socionext,uniphier-sld8", .clk_rate = 80000000 },
{ .compatible = "socionext,uniphier-pro5", .clk_rate = 73728000 },
{ .compatible = "socionext,uniphier-pxs2", .clk_rate = 88888888 },
{ .compatible = "socionext,uniphier-ld6b", .clk_rate = 88888888 },
{ .compatible = "socionext,uniphier-ld11", .clk_rate = 58823529 },
{ .compatible = "socionext,uniphier-ld20", .clk_rate = 58823529 },
{ .compatible = "socionext,uniphier-pxs3", .clk_rate = 58823529 },
{ /* sentinel */ },
};
static int uniphier_serial_probe(struct udevice *dev)
{
struct uniphier_serial_priv *priv = dev_get_priv(dev);
const struct uniphier_serial_clk_data *clk_data;
ofnode root_node;
fdt_addr_t base;
u32 tmp;
base = devfdt_get_addr(dev);
if (base == FDT_ADDR_T_NONE)
return -EINVAL;
priv->membase = devm_ioremap(dev, base, SZ_64);
if (!priv->membase)
return -ENOMEM;
root_node = ofnode_path("/");
clk_data = uniphier_serial_clk_data;
while (clk_data->compatible) {
if (ofnode_device_is_compatible(root_node,
clk_data->compatible))
break;
clk_data++;
}
if (WARN_ON(!clk_data->compatible))
return -ENOTSUPP;
priv->uartclk = clk_data->clk_rate;
/* flush the trasmitter empty before changing hw setting */
while (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_TEMT))
;
/* enable FIFO */
tmp = readl(priv->membase + UNIPHIER_UART_CHAR_FCR);
tmp &= ~UNIPHIER_UART_FCR_MASK;
tmp |= FIELD_PREP(UNIPHIER_UART_FCR_MASK, UART_FCR_ENABLE_FIFO);
writel(tmp, priv->membase + UNIPHIER_UART_CHAR_FCR);
tmp = readl(priv->membase + UNIPHIER_UART_LCR_MCR);
tmp &= ~UNIPHIER_UART_LCR_MASK;
tmp |= FIELD_PREP(UNIPHIER_UART_LCR_MASK, UART_LCR_WLEN8);
writel(tmp, priv->membase + UNIPHIER_UART_LCR_MCR);
return 0;
}
static const struct udevice_id uniphier_uart_of_match[] = {
{ .compatible = "socionext,uniphier-uart" },
{ /* sentinel */ }
};
static const struct dm_serial_ops uniphier_serial_ops = {
.setbrg = uniphier_serial_setbrg,
.getc = uniphier_serial_getc,
.putc = uniphier_serial_putc,
.pending = uniphier_serial_pending,
};
U_BOOT_DRIVER(uniphier_serial) = {
.name = "uniphier-uart",
.id = UCLASS_SERIAL,
.of_match = uniphier_uart_of_match,
.probe = uniphier_serial_probe,
.priv_auto_alloc_size = sizeof(struct uniphier_serial_priv),
.ops = &uniphier_serial_ops,
};
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