xref: /openbmc/linux/arch/arm/mach-lpc32xx/common.c (revision 12eb4683)
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  * System reset via the watchdog timer
61  */
62 static void lpc32xx_watchdog_reset(void)
63 {
64 	/* Make sure WDT clocks are enabled */
65 	__raw_writel(LPC32XX_CLKPWR_PWMCLK_WDOG_EN,
66 		LPC32XX_CLKPWR_TIMER_CLK_CTRL);
67 
68 	/* Instant assert of RESETOUT_N with pulse length 1mS */
69 	__raw_writel(13000, io_p2v(LPC32XX_WDTIM_BASE + 0x18));
70 	__raw_writel(0x70, io_p2v(LPC32XX_WDTIM_BASE + 0xC));
71 }
72 
73 /*
74  * Detects and returns IRAM size for the device variation
75  */
76 #define LPC32XX_IRAM_BANK_SIZE SZ_128K
77 static u32 iram_size;
78 u32 lpc32xx_return_iram_size(void)
79 {
80 	if (iram_size == 0) {
81 		u32 savedval1, savedval2;
82 		void __iomem *iramptr1, *iramptr2;
83 
84 		iramptr1 = io_p2v(LPC32XX_IRAM_BASE);
85 		iramptr2 = io_p2v(LPC32XX_IRAM_BASE + LPC32XX_IRAM_BANK_SIZE);
86 		savedval1 = __raw_readl(iramptr1);
87 		savedval2 = __raw_readl(iramptr2);
88 
89 		if (savedval1 == savedval2) {
90 			__raw_writel(savedval2 + 1, iramptr2);
91 			if (__raw_readl(iramptr1) == savedval2 + 1)
92 				iram_size = LPC32XX_IRAM_BANK_SIZE;
93 			else
94 				iram_size = LPC32XX_IRAM_BANK_SIZE * 2;
95 			__raw_writel(savedval2, iramptr2);
96 		} else
97 			iram_size = LPC32XX_IRAM_BANK_SIZE * 2;
98 	}
99 
100 	return iram_size;
101 }
102 
103 /*
104  * Computes PLL rate from PLL register and input clock
105  */
106 u32 clk_check_pll_setup(u32 ifreq, struct clk_pll_setup *pllsetup)
107 {
108 	u32 ilfreq, p, m, n, fcco, fref, cfreq;
109 	int mode;
110 
111 	/*
112 	 * PLL requirements
113 	 * ifreq must be >= 1MHz and <= 20MHz
114 	 * FCCO must be >= 156MHz and <= 320MHz
115 	 * FREF must be >= 1MHz and <= 27MHz
116 	 * Assume the passed input data is not valid
117 	 */
118 
119 	ilfreq = ifreq;
120 	m = pllsetup->pll_m;
121 	n = pllsetup->pll_n;
122 	p = pllsetup->pll_p;
123 
124 	mode = (pllsetup->cco_bypass_b15 << 2) |
125 		(pllsetup->direct_output_b14 << 1) |
126 	pllsetup->fdbk_div_ctrl_b13;
127 
128 	switch (mode) {
129 	case 0x0: /* Non-integer mode */
130 		cfreq = (m * ilfreq) / (2 * p * n);
131 		fcco = (m * ilfreq) / n;
132 		fref = ilfreq / n;
133 		break;
134 
135 	case 0x1: /* integer mode */
136 		cfreq = (m * ilfreq) / n;
137 		fcco = (m * ilfreq) / (n * 2 * p);
138 		fref = ilfreq / n;
139 		break;
140 
141 	case 0x2:
142 	case 0x3: /* Direct mode */
143 		cfreq = (m * ilfreq) / n;
144 		fcco = cfreq;
145 		fref = ilfreq / n;
146 		break;
147 
148 	case 0x4:
149 	case 0x5: /* Bypass mode */
150 		cfreq = ilfreq / (2 * p);
151 		fcco = 156000000;
152 		fref = 1000000;
153 		break;
154 
155 	case 0x6:
156 	case 0x7: /* Direct bypass mode */
157 	default:
158 		cfreq = ilfreq;
159 		fcco = 156000000;
160 		fref = 1000000;
161 		break;
162 	}
163 
164 	if (fcco < 156000000 || fcco > 320000000)
165 		cfreq = 0;
166 
167 	if (fref < 1000000 || fref > 27000000)
168 		cfreq = 0;
169 
170 	return (u32) cfreq;
171 }
172 
173 u32 clk_get_pclk_div(void)
174 {
175 	return 1 + ((__raw_readl(LPC32XX_CLKPWR_HCLK_DIV) >> 2) & 0x1F);
176 }
177 
178 static struct map_desc lpc32xx_io_desc[] __initdata = {
179 	{
180 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB0_START),
181 		.pfn		= __phys_to_pfn(LPC32XX_AHB0_START),
182 		.length		= LPC32XX_AHB0_SIZE,
183 		.type		= MT_DEVICE
184 	},
185 	{
186 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB1_START),
187 		.pfn		= __phys_to_pfn(LPC32XX_AHB1_START),
188 		.length		= LPC32XX_AHB1_SIZE,
189 		.type		= MT_DEVICE
190 	},
191 	{
192 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_FABAPB_START),
193 		.pfn		= __phys_to_pfn(LPC32XX_FABAPB_START),
194 		.length		= LPC32XX_FABAPB_SIZE,
195 		.type		= MT_DEVICE
196 	},
197 	{
198 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_IRAM_BASE),
199 		.pfn		= __phys_to_pfn(LPC32XX_IRAM_BASE),
200 		.length		= (LPC32XX_IRAM_BANK_SIZE * 2),
201 		.type		= MT_DEVICE
202 	},
203 };
204 
205 void __init lpc32xx_map_io(void)
206 {
207 	iotable_init(lpc32xx_io_desc, ARRAY_SIZE(lpc32xx_io_desc));
208 }
209 
210 void lpc23xx_restart(enum reboot_mode mode, const char *cmd)
211 {
212 	switch (mode) {
213 	case REBOOT_SOFT:
214 	case REBOOT_HARD:
215 		lpc32xx_watchdog_reset();
216 		break;
217 
218 	default:
219 		/* Do nothing */
220 		break;
221 	}
222 
223 	/* Wait for watchdog to reset system */
224 	while (1)
225 		;
226 }
227 
228 static int __init lpc32xx_check_uid(void)
229 {
230 	u32 uid[4];
231 
232 	lpc32xx_get_uid(uid);
233 
234 	printk(KERN_INFO "LPC32XX unique ID: %08x%08x%08x%08x\n",
235 		uid[3], uid[2], uid[1], uid[0]);
236 
237 	if (!system_serial_low && !system_serial_high) {
238 		system_serial_low = uid[0];
239 		system_serial_high = uid[1];
240 	}
241 
242 	return 1;
243 }
244 arch_initcall(lpc32xx_check_uid);
245