xref: /openbmc/linux/arch/arm/mach-lpc32xx/common.c (revision 94cdda6b)
1 /*
2  * arch/arm/mach-lpc32xx/common.c
3  *
4  * Author: Kevin Wells <kevin.wells@nxp.com>
5  *
6  * Copyright (C) 2010 NXP Semiconductors
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  */
18 
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/err.h>
24 #include <linux/i2c.h>
25 #include <linux/i2c-pnx.h>
26 #include <linux/io.h>
27 
28 #include <asm/mach/map.h>
29 #include <asm/system_info.h>
30 
31 #include <mach/hardware.h>
32 #include <mach/platform.h>
33 #include "common.h"
34 
35 /*
36  * Returns the unique ID for the device
37  */
38 void lpc32xx_get_uid(u32 devid[4])
39 {
40 	int i;
41 
42 	for (i = 0; i < 4; i++)
43 		devid[i] = __raw_readl(LPC32XX_CLKPWR_DEVID(i << 2));
44 }
45 
46 /*
47  * Returns SYSCLK source
48  * 0 = PLL397, 1 = main oscillator
49  */
50 int clk_is_sysclk_mainosc(void)
51 {
52 	if ((__raw_readl(LPC32XX_CLKPWR_SYSCLK_CTRL) &
53 		LPC32XX_CLKPWR_SYSCTRL_SYSCLKMUX) == 0)
54 		return 1;
55 
56 	return 0;
57 }
58 
59 /*
60  * Detects and returns IRAM size for the device variation
61  */
62 #define LPC32XX_IRAM_BANK_SIZE SZ_128K
63 static u32 iram_size;
64 u32 lpc32xx_return_iram_size(void)
65 {
66 	if (iram_size == 0) {
67 		u32 savedval1, savedval2;
68 		void __iomem *iramptr1, *iramptr2;
69 
70 		iramptr1 = io_p2v(LPC32XX_IRAM_BASE);
71 		iramptr2 = io_p2v(LPC32XX_IRAM_BASE + LPC32XX_IRAM_BANK_SIZE);
72 		savedval1 = __raw_readl(iramptr1);
73 		savedval2 = __raw_readl(iramptr2);
74 
75 		if (savedval1 == savedval2) {
76 			__raw_writel(savedval2 + 1, iramptr2);
77 			if (__raw_readl(iramptr1) == savedval2 + 1)
78 				iram_size = LPC32XX_IRAM_BANK_SIZE;
79 			else
80 				iram_size = LPC32XX_IRAM_BANK_SIZE * 2;
81 			__raw_writel(savedval2, iramptr2);
82 		} else
83 			iram_size = LPC32XX_IRAM_BANK_SIZE * 2;
84 	}
85 
86 	return iram_size;
87 }
88 EXPORT_SYMBOL_GPL(lpc32xx_return_iram_size);
89 
90 /*
91  * Computes PLL rate from PLL register and input clock
92  */
93 u32 clk_check_pll_setup(u32 ifreq, struct clk_pll_setup *pllsetup)
94 {
95 	u32 ilfreq, p, m, n, fcco, fref, cfreq;
96 	int mode;
97 
98 	/*
99 	 * PLL requirements
100 	 * ifreq must be >= 1MHz and <= 20MHz
101 	 * FCCO must be >= 156MHz and <= 320MHz
102 	 * FREF must be >= 1MHz and <= 27MHz
103 	 * Assume the passed input data is not valid
104 	 */
105 
106 	ilfreq = ifreq;
107 	m = pllsetup->pll_m;
108 	n = pllsetup->pll_n;
109 	p = pllsetup->pll_p;
110 
111 	mode = (pllsetup->cco_bypass_b15 << 2) |
112 		(pllsetup->direct_output_b14 << 1) |
113 	pllsetup->fdbk_div_ctrl_b13;
114 
115 	switch (mode) {
116 	case 0x0: /* Non-integer mode */
117 		cfreq = (m * ilfreq) / (2 * p * n);
118 		fcco = (m * ilfreq) / n;
119 		fref = ilfreq / n;
120 		break;
121 
122 	case 0x1: /* integer mode */
123 		cfreq = (m * ilfreq) / n;
124 		fcco = (m * ilfreq) / (n * 2 * p);
125 		fref = ilfreq / n;
126 		break;
127 
128 	case 0x2:
129 	case 0x3: /* Direct mode */
130 		cfreq = (m * ilfreq) / n;
131 		fcco = cfreq;
132 		fref = ilfreq / n;
133 		break;
134 
135 	case 0x4:
136 	case 0x5: /* Bypass mode */
137 		cfreq = ilfreq / (2 * p);
138 		fcco = 156000000;
139 		fref = 1000000;
140 		break;
141 
142 	case 0x6:
143 	case 0x7: /* Direct bypass mode */
144 	default:
145 		cfreq = ilfreq;
146 		fcco = 156000000;
147 		fref = 1000000;
148 		break;
149 	}
150 
151 	if (fcco < 156000000 || fcco > 320000000)
152 		cfreq = 0;
153 
154 	if (fref < 1000000 || fref > 27000000)
155 		cfreq = 0;
156 
157 	return (u32) cfreq;
158 }
159 
160 u32 clk_get_pclk_div(void)
161 {
162 	return 1 + ((__raw_readl(LPC32XX_CLKPWR_HCLK_DIV) >> 2) & 0x1F);
163 }
164 
165 static struct map_desc lpc32xx_io_desc[] __initdata = {
166 	{
167 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB0_START),
168 		.pfn		= __phys_to_pfn(LPC32XX_AHB0_START),
169 		.length		= LPC32XX_AHB0_SIZE,
170 		.type		= MT_DEVICE
171 	},
172 	{
173 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB1_START),
174 		.pfn		= __phys_to_pfn(LPC32XX_AHB1_START),
175 		.length		= LPC32XX_AHB1_SIZE,
176 		.type		= MT_DEVICE
177 	},
178 	{
179 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_FABAPB_START),
180 		.pfn		= __phys_to_pfn(LPC32XX_FABAPB_START),
181 		.length		= LPC32XX_FABAPB_SIZE,
182 		.type		= MT_DEVICE
183 	},
184 	{
185 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_IRAM_BASE),
186 		.pfn		= __phys_to_pfn(LPC32XX_IRAM_BASE),
187 		.length		= (LPC32XX_IRAM_BANK_SIZE * 2),
188 		.type		= MT_DEVICE
189 	},
190 };
191 
192 void __init lpc32xx_map_io(void)
193 {
194 	iotable_init(lpc32xx_io_desc, ARRAY_SIZE(lpc32xx_io_desc));
195 }
196 
197 void lpc23xx_restart(enum reboot_mode mode, const char *cmd)
198 {
199 	/* Make sure WDT clocks are enabled */
200 	__raw_writel(LPC32XX_CLKPWR_PWMCLK_WDOG_EN,
201 		LPC32XX_CLKPWR_TIMER_CLK_CTRL);
202 
203 	/* Instant assert of RESETOUT_N with pulse length 1mS */
204 	__raw_writel(13000, io_p2v(LPC32XX_WDTIM_BASE + 0x18));
205 	__raw_writel(0x70, io_p2v(LPC32XX_WDTIM_BASE + 0xC));
206 
207 	/* Wait for watchdog to reset system */
208 	while (1)
209 		;
210 }
211 
212 static int __init lpc32xx_check_uid(void)
213 {
214 	u32 uid[4];
215 
216 	lpc32xx_get_uid(uid);
217 
218 	printk(KERN_INFO "LPC32XX unique ID: %08x%08x%08x%08x\n",
219 		uid[3], uid[2], uid[1], uid[0]);
220 
221 	if (!system_serial_low && !system_serial_high) {
222 		system_serial_low = uid[0];
223 		system_serial_high = uid[1];
224 	}
225 
226 	return 1;
227 }
228 arch_initcall(lpc32xx_check_uid);
229