dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / power / reset / at91-reset.c
blob3f6b5dd7c3d4e47041611b3e6baab483c2ae41db
1 /*
2 * Atmel AT91 SAM9 & SAMA5 SoCs reset code
4 * Copyright (C) 2007 Atmel Corporation.
5 * Copyright (C) BitBox Ltd 2010
6 * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcosoft.com>
7 * Copyright (C) 2014 Free Electrons
9 * This file is licensed under the terms of the GNU General Public
10 * License version 2. This program is licensed "as is" without any
11 * warranty of any kind, whether express or implied.
14 #include <linux/clk.h>
15 #include <linux/io.h>
16 #include <linux/module.h>
17 #include <linux/of_address.h>
18 #include <linux/platform_device.h>
19 #include <linux/reboot.h>
21 #include <soc/at91/at91sam9_ddrsdr.h>
22 #include <soc/at91/at91sam9_sdramc.h>
24 #define AT91_RSTC_CR 0x00 /* Reset Controller Control Register */
25 #define AT91_RSTC_PROCRST BIT(0) /* Processor Reset */
26 #define AT91_RSTC_PERRST BIT(2) /* Peripheral Reset */
27 #define AT91_RSTC_EXTRST BIT(3) /* External Reset */
28 #define AT91_RSTC_KEY (0xa5 << 24) /* KEY Password */
30 #define AT91_RSTC_SR 0x04 /* Reset Controller Status Register */
31 #define AT91_RSTC_URSTS BIT(0) /* User Reset Status */
32 #define AT91_RSTC_RSTTYP GENMASK(10, 8) /* Reset Type */
33 #define AT91_RSTC_NRSTL BIT(16) /* NRST Pin Level */
34 #define AT91_RSTC_SRCMP BIT(17) /* Software Reset Command in Progress */
36 #define AT91_RSTC_MR 0x08 /* Reset Controller Mode Register */
37 #define AT91_RSTC_URSTEN BIT(0) /* User Reset Enable */
38 #define AT91_RSTC_URSTIEN BIT(4) /* User Reset Interrupt Enable */
39 #define AT91_RSTC_ERSTL GENMASK(11, 8) /* External Reset Length */
41 enum reset_type {
42 RESET_TYPE_GENERAL = 0,
43 RESET_TYPE_WAKEUP = 1,
44 RESET_TYPE_WATCHDOG = 2,
45 RESET_TYPE_SOFTWARE = 3,
46 RESET_TYPE_USER = 4,
49 static void __iomem *at91_ramc_base[2], *at91_rstc_base;
50 static struct clk *sclk;
53 * unless the SDRAM is cleanly shutdown before we hit the
54 * reset register it can be left driving the data bus and
55 * killing the chance of a subsequent boot from NAND
57 static int at91sam9260_restart(struct notifier_block *this, unsigned long mode,
58 void *cmd)
60 asm volatile(
61 /* Align to cache lines */
62 ".balign 32\n\t"
64 /* Disable SDRAM accesses */
65 "str %2, [%0, #" __stringify(AT91_SDRAMC_TR) "]\n\t"
67 /* Power down SDRAM */
68 "str %3, [%0, #" __stringify(AT91_SDRAMC_LPR) "]\n\t"
70 /* Reset CPU */
71 "str %4, [%1, #" __stringify(AT91_RSTC_CR) "]\n\t"
73 "b .\n\t"
75 : "r" (at91_ramc_base[0]),
76 "r" (at91_rstc_base),
77 "r" (1),
78 "r" cpu_to_le32(AT91_SDRAMC_LPCB_POWER_DOWN),
79 "r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST));
81 return NOTIFY_DONE;
84 static int at91sam9g45_restart(struct notifier_block *this, unsigned long mode,
85 void *cmd)
87 asm volatile(
89 * Test wether we have a second RAM controller to care
90 * about.
92 * First, test that we can dereference the virtual address.
94 "cmp %1, #0\n\t"
95 "beq 1f\n\t"
97 /* Then, test that the RAM controller is enabled */
98 "ldr r0, [%1]\n\t"
99 "cmp r0, #0\n\t"
101 /* Align to cache lines */
102 ".balign 32\n\t"
104 /* Disable SDRAM0 accesses */
105 "1: str %3, [%0, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t"
106 /* Power down SDRAM0 */
107 " str %4, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
108 /* Disable SDRAM1 accesses */
109 " strne %3, [%1, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t"
110 /* Power down SDRAM1 */
111 " strne %4, [%1, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
112 /* Reset CPU */
113 " str %5, [%2, #" __stringify(AT91_RSTC_CR) "]\n\t"
115 " b .\n\t"
117 : "r" (at91_ramc_base[0]),
118 "r" (at91_ramc_base[1]),
119 "r" (at91_rstc_base),
120 "r" (1),
121 "r" cpu_to_le32(AT91_DDRSDRC_LPCB_POWER_DOWN),
122 "r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST)
123 : "r0");
125 return NOTIFY_DONE;
128 static int sama5d3_restart(struct notifier_block *this, unsigned long mode,
129 void *cmd)
131 writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST),
132 at91_rstc_base);
134 return NOTIFY_DONE;
137 static void __init at91_reset_status(struct platform_device *pdev)
139 u32 reg = readl(at91_rstc_base + AT91_RSTC_SR);
140 char *reason;
142 switch ((reg & AT91_RSTC_RSTTYP) >> 8) {
143 case RESET_TYPE_GENERAL:
144 reason = "general reset";
145 break;
146 case RESET_TYPE_WAKEUP:
147 reason = "wakeup";
148 break;
149 case RESET_TYPE_WATCHDOG:
150 reason = "watchdog reset";
151 break;
152 case RESET_TYPE_SOFTWARE:
153 reason = "software reset";
154 break;
155 case RESET_TYPE_USER:
156 reason = "user reset";
157 break;
158 default:
159 reason = "unknown reset";
160 break;
163 pr_info("AT91: Starting after %s\n", reason);
166 static const struct of_device_id at91_ramc_of_match[] = {
167 { .compatible = "atmel,at91sam9260-sdramc", },
168 { .compatible = "atmel,at91sam9g45-ddramc", },
169 { /* sentinel */ }
172 static const struct of_device_id at91_reset_of_match[] = {
173 { .compatible = "atmel,at91sam9260-rstc", .data = at91sam9260_restart },
174 { .compatible = "atmel,at91sam9g45-rstc", .data = at91sam9g45_restart },
175 { .compatible = "atmel,sama5d3-rstc", .data = sama5d3_restart },
176 { /* sentinel */ }
179 static struct notifier_block at91_restart_nb = {
180 .priority = 192,
183 static int __init at91_reset_probe(struct platform_device *pdev)
185 const struct of_device_id *match;
186 struct device_node *np;
187 int ret, idx = 0;
189 at91_rstc_base = of_iomap(pdev->dev.of_node, 0);
190 if (!at91_rstc_base) {
191 dev_err(&pdev->dev, "Could not map reset controller address\n");
192 return -ENODEV;
195 if (!of_device_is_compatible(pdev->dev.of_node, "atmel,sama5d3-rstc")) {
196 /* we need to shutdown the ddr controller, so get ramc base */
197 for_each_matching_node(np, at91_ramc_of_match) {
198 at91_ramc_base[idx] = of_iomap(np, 0);
199 if (!at91_ramc_base[idx]) {
200 dev_err(&pdev->dev, "Could not map ram controller address\n");
201 return -ENODEV;
203 idx++;
207 match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
208 at91_restart_nb.notifier_call = match->data;
210 sclk = devm_clk_get(&pdev->dev, NULL);
211 if (IS_ERR(sclk))
212 return PTR_ERR(sclk);
214 ret = clk_prepare_enable(sclk);
215 if (ret) {
216 dev_err(&pdev->dev, "Could not enable slow clock\n");
217 return ret;
220 ret = register_restart_handler(&at91_restart_nb);
221 if (ret) {
222 clk_disable_unprepare(sclk);
223 return ret;
226 at91_reset_status(pdev);
228 return 0;
231 static int __exit at91_reset_remove(struct platform_device *pdev)
233 unregister_restart_handler(&at91_restart_nb);
234 clk_disable_unprepare(sclk);
236 return 0;
239 static const struct platform_device_id at91_reset_plat_match[] = {
240 { "at91-sam9260-reset", (unsigned long)at91sam9260_restart },
241 { "at91-sam9g45-reset", (unsigned long)at91sam9g45_restart },
242 { /* sentinel */ }
245 static struct platform_driver at91_reset_driver = {
246 .remove = __exit_p(at91_reset_remove),
247 .driver = {
248 .name = "at91-reset",
249 .of_match_table = at91_reset_of_match,
251 .id_table = at91_reset_plat_match,
253 module_platform_driver_probe(at91_reset_driver, at91_reset_probe);
255 MODULE_AUTHOR("Atmel Corporation");
256 MODULE_DESCRIPTION("Reset driver for Atmel SoCs");
257 MODULE_LICENSE("GPL v2");