1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * OMAP1 reset support
4  */
5 #include <linux/kernel.h>
6 #include <linux/io.h>
7 #include <linux/reboot.h>
8 
9 #include <mach/hardware.h>
10 
11 #include "iomap.h"
12 #include "common.h"
13 
14 /* ARM_SYSST bit shifts related to SoC reset sources */
15 #define ARM_SYSST_POR_SHIFT				5
16 #define ARM_SYSST_EXT_RST_SHIFT				4
17 #define ARM_SYSST_ARM_WDRST_SHIFT			2
18 #define ARM_SYSST_GLOB_SWRST_SHIFT			1
19 
20 /* Standardized reset source bits (across all OMAP SoCs) */
21 #define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT		0
22 #define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT		1
23 #define OMAP_MPU_WD_RST_SRC_ID_SHIFT			3
24 #define OMAP_EXTWARM_RST_SRC_ID_SHIFT			5
25 
26 
omap1_restart(enum reboot_mode mode,const char * cmd)27 void omap1_restart(enum reboot_mode mode, const char *cmd)
28 {
29 	/*
30 	 * Workaround for 5912/1611b bug mentioned in sprz209d.pdf p. 28
31 	 * "Global Software Reset Affects Traffic Controller Frequency".
32 	 */
33 	if (cpu_is_omap5912()) {
34 		omap_writew(omap_readw(DPLL_CTL) & ~(1 << 4), DPLL_CTL);
35 		omap_writew(0x8, ARM_RSTCT1);
36 	}
37 
38 	omap_writew(1, ARM_RSTCT1);
39 }
40 
41 /**
42  * omap1_get_reset_sources - return the source of the SoC's last reset
43  *
44  * Returns bits that represent the last reset source for the SoC.  The
45  * format is standardized across OMAPs for use by the OMAP watchdog.
46  */
omap1_get_reset_sources(void)47 u32 omap1_get_reset_sources(void)
48 {
49 	u32 ret = 0;
50 	u16 rs;
51 
52 	rs = __raw_readw(OMAP1_IO_ADDRESS(ARM_SYSST));
53 
54 	if (rs & (1 << ARM_SYSST_POR_SHIFT))
55 		ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT;
56 	if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT))
57 		ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT;
58 	if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT))
59 		ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT;
60 	if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT))
61 		ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT;
62 
63 	return ret;
64 }
65