xref: /openbmc/linux/arch/arm/mach-lpc32xx/common.c (revision 455f9726)
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 EXPORT_SYMBOL_GPL(lpc32xx_return_iram_size);
103 
104 /*
105  * Computes PLL rate from PLL register and input clock
106  */
107 u32 clk_check_pll_setup(u32 ifreq, struct clk_pll_setup *pllsetup)
108 {
109 	u32 ilfreq, p, m, n, fcco, fref, cfreq;
110 	int mode;
111 
112 	/*
113 	 * PLL requirements
114 	 * ifreq must be >= 1MHz and <= 20MHz
115 	 * FCCO must be >= 156MHz and <= 320MHz
116 	 * FREF must be >= 1MHz and <= 27MHz
117 	 * Assume the passed input data is not valid
118 	 */
119 
120 	ilfreq = ifreq;
121 	m = pllsetup->pll_m;
122 	n = pllsetup->pll_n;
123 	p = pllsetup->pll_p;
124 
125 	mode = (pllsetup->cco_bypass_b15 << 2) |
126 		(pllsetup->direct_output_b14 << 1) |
127 	pllsetup->fdbk_div_ctrl_b13;
128 
129 	switch (mode) {
130 	case 0x0: /* Non-integer mode */
131 		cfreq = (m * ilfreq) / (2 * p * n);
132 		fcco = (m * ilfreq) / n;
133 		fref = ilfreq / n;
134 		break;
135 
136 	case 0x1: /* integer mode */
137 		cfreq = (m * ilfreq) / n;
138 		fcco = (m * ilfreq) / (n * 2 * p);
139 		fref = ilfreq / n;
140 		break;
141 
142 	case 0x2:
143 	case 0x3: /* Direct mode */
144 		cfreq = (m * ilfreq) / n;
145 		fcco = cfreq;
146 		fref = ilfreq / n;
147 		break;
148 
149 	case 0x4:
150 	case 0x5: /* Bypass mode */
151 		cfreq = ilfreq / (2 * p);
152 		fcco = 156000000;
153 		fref = 1000000;
154 		break;
155 
156 	case 0x6:
157 	case 0x7: /* Direct bypass mode */
158 	default:
159 		cfreq = ilfreq;
160 		fcco = 156000000;
161 		fref = 1000000;
162 		break;
163 	}
164 
165 	if (fcco < 156000000 || fcco > 320000000)
166 		cfreq = 0;
167 
168 	if (fref < 1000000 || fref > 27000000)
169 		cfreq = 0;
170 
171 	return (u32) cfreq;
172 }
173 
174 u32 clk_get_pclk_div(void)
175 {
176 	return 1 + ((__raw_readl(LPC32XX_CLKPWR_HCLK_DIV) >> 2) & 0x1F);
177 }
178 
179 static struct map_desc lpc32xx_io_desc[] __initdata = {
180 	{
181 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB0_START),
182 		.pfn		= __phys_to_pfn(LPC32XX_AHB0_START),
183 		.length		= LPC32XX_AHB0_SIZE,
184 		.type		= MT_DEVICE
185 	},
186 	{
187 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB1_START),
188 		.pfn		= __phys_to_pfn(LPC32XX_AHB1_START),
189 		.length		= LPC32XX_AHB1_SIZE,
190 		.type		= MT_DEVICE
191 	},
192 	{
193 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_FABAPB_START),
194 		.pfn		= __phys_to_pfn(LPC32XX_FABAPB_START),
195 		.length		= LPC32XX_FABAPB_SIZE,
196 		.type		= MT_DEVICE
197 	},
198 	{
199 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_IRAM_BASE),
200 		.pfn		= __phys_to_pfn(LPC32XX_IRAM_BASE),
201 		.length		= (LPC32XX_IRAM_BANK_SIZE * 2),
202 		.type		= MT_DEVICE
203 	},
204 };
205 
206 void __init lpc32xx_map_io(void)
207 {
208 	iotable_init(lpc32xx_io_desc, ARRAY_SIZE(lpc32xx_io_desc));
209 }
210 
211 void lpc23xx_restart(enum reboot_mode mode, const char *cmd)
212 {
213 	switch (mode) {
214 	case REBOOT_SOFT:
215 	case REBOOT_HARD:
216 		lpc32xx_watchdog_reset();
217 		break;
218 
219 	default:
220 		/* Do nothing */
221 		break;
222 	}
223 
224 	/* Wait for watchdog to reset system */
225 	while (1)
226 		;
227 }
228 
229 static int __init lpc32xx_check_uid(void)
230 {
231 	u32 uid[4];
232 
233 	lpc32xx_get_uid(uid);
234 
235 	printk(KERN_INFO "LPC32XX unique ID: %08x%08x%08x%08x\n",
236 		uid[3], uid[2], uid[1], uid[0]);
237 
238 	if (!system_serial_low && !system_serial_high) {
239 		system_serial_low = uid[0];
240 		system_serial_high = uid[1];
241 	}
242 
243 	return 1;
244 }
245 arch_initcall(lpc32xx_check_uid);
246