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