summaryrefslogtreecommitdiffstats
path: root/kernel/arch/arm/mach-lpc32xx/serial.c
blob: 05621a29fba22cb5a1754f525d90817c9eaf3c57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * arch/arm/mach-lpc32xx/serial.c
 *
 * Author: Kevin Wells <kevin.wells@nxp.com>
 *
 * Copyright (C) 2010 NXP Semiconductors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/serial_8250.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <mach/hardware.h>
#include <mach/platform.h>
#include "common.h"

#define LPC32XX_SUART_FIFO_SIZE	64

struct uartinit {
	char *uart_ck_name;
	u32 ck_mode_mask;
	void __iomem *pdiv_clk_reg;
	resource_size_t mapbase;
};

static struct uartinit uartinit_data[] __initdata = {
	{
		.uart_ck_name = "uart5_ck",
		.ck_mode_mask =
			LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 5),
		.pdiv_clk_reg = LPC32XX_CLKPWR_UART5_CLK_CTRL,
		.mapbase = LPC32XX_UART5_BASE,
	},
	{
		.uart_ck_name = "uart3_ck",
		.ck_mode_mask =
			LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 3),
		.pdiv_clk_reg = LPC32XX_CLKPWR_UART3_CLK_CTRL,
		.mapbase = LPC32XX_UART3_BASE,
	},
	{
		.uart_ck_name = "uart4_ck",
		.ck_mode_mask =
			LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 4),
		.pdiv_clk_reg = LPC32XX_CLKPWR_UART4_CLK_CTRL,
		.mapbase = LPC32XX_UART4_BASE,
	},
	{
		.uart_ck_name = "uart6_ck",
		.ck_mode_mask =
			LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 6),
		.pdiv_clk_reg = LPC32XX_CLKPWR_UART6_CLK_CTRL,
		.mapbase = LPC32XX_UART6_BASE,
	},
};

void __init lpc32xx_serial_init(void)
{
	u32 tmp, clkmodes = 0;
	struct clk *clk;
	unsigned int puart;
	int i, j;

	/* UART clocks are off, let clock driver manage them */
	__raw_writel(0, LPC32XX_CLKPWR_UART_CLK_CTRL);

	for (i = 0; i < ARRAY_SIZE(uartinit_data); i++) {
		clk = clk_get(NULL, uartinit_data[i].uart_ck_name);
		if (!IS_ERR(clk)) {
			clk_enable(clk);
		}

		/* Setup UART clock modes for all UARTs, disable autoclock */
		clkmodes |= uartinit_data[i].ck_mode_mask;

		/* pre-UART clock divider set to 1 */
		__raw_writel(0x0101, uartinit_data[i].pdiv_clk_reg);

		/*
		 * Force a flush of the RX FIFOs to work around a
		 * HW bug
		 */
		puart = uartinit_data[i].mapbase;
		__raw_writel(0xC1, LPC32XX_UART_IIR_FCR(puart));
		__raw_writel(0x00, LPC32XX_UART_DLL_FIFO(puart));
		j = LPC32XX_SUART_FIFO_SIZE;
		while (j--)
			tmp = __raw_readl(
				LPC32XX_UART_DLL_FIFO(puart));
		__raw_writel(0, LPC32XX_UART_IIR_FCR(puart));
	}

	/* This needs to be done after all UART clocks are setup */
	__raw_writel(clkmodes, LPC32XX_UARTCTL_CLKMODE);
	for (i = 0; i < ARRAY_SIZE(uartinit_data); i++) {
		/* Force a flush of the RX FIFOs to work around a HW bug */
		puart = uartinit_data[i].mapbase;
		__raw_writel(0xC1, LPC32XX_UART_IIR_FCR(puart));
		__raw_writel(0x00, LPC32XX_UART_DLL_FIFO(puart));
		j = LPC32XX_SUART_FIFO_SIZE;
		while (j--)
			tmp = __raw_readl(LPC32XX_UART_DLL_FIFO(puart));
		__raw_writel(0, LPC32XX_UART_IIR_FCR(puart));
	}

	/* Disable IrDA pulsing support on UART6 */
	tmp = __raw_readl(LPC32XX_UARTCTL_CTRL);
	tmp |= LPC32XX_UART_UART6_IRDAMOD_BYPASS;
	__raw_writel(tmp, LPC32XX_UARTCTL_CTRL);

	/* Disable UART5->USB transparent mode or USB won't work */
	tmp = __raw_readl(LPC32XX_UARTCTL_CTRL);
	tmp &= ~LPC32XX_UART_U5_ROUTE_TO_USB;
	__raw_writel(tmp, LPC32XX_UARTCTL_CTRL);
}