Commit | Line | Data |
---|---|---|
2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9e1b7498 PW |
2 | /* |
3 | * IP block integration code for the HDQ1W/1-wire IP block | |
4 | * | |
5 | * Copyright (C) 2012 Texas Instruments, Inc. | |
6 | * Paul Walmsley | |
7 | * | |
8 | * Based on the I2C reset code in arch/arm/mach-omap2/i2c.c by | |
9 | * Avinash.H.M <avinashhm@ti.com> | |
9e1b7498 PW |
10 | */ |
11 | ||
96b1b29d PW |
12 | #include <linux/kernel.h> |
13 | #include <linux/init.h> | |
14 | #include <linux/err.h> | |
15 | #include <linux/platform_device.h> | |
16 | ||
b76c8b19 | 17 | #include "soc.h" |
2a296c8f | 18 | #include "omap_hwmod.h" |
25c7d49e | 19 | #include "omap_device.h" |
a0b30ca5 | 20 | #include "hdq1w.h" |
9e1b7498 | 21 | |
b13159af | 22 | #include "prm.h" |
9e1b7498 PW |
23 | #include "common.h" |
24 | ||
9e1b7498 PW |
25 | /** |
26 | * omap_hdq1w_reset - reset the OMAP HDQ1W module | |
27 | * @oh: struct omap_hwmod * | |
28 | * | |
29 | * OCP soft reset the HDQ1W IP block. Section 20.6.1.4 "HDQ1W/1-Wire | |
30 | * Software Reset" of the OMAP34xx Technical Reference Manual Revision | |
31 | * ZR (SWPU223R) does not include the rather important fact that, for | |
32 | * the reset to succeed, the HDQ1W module's internal clock gate must be | |
33 | * programmed to allow the clock to propagate to the rest of the | |
34 | * module. In this sense, it's rather similar to the I2C custom reset | |
35 | * function. Returns 0. | |
36 | */ | |
37 | int omap_hdq1w_reset(struct omap_hwmod *oh) | |
38 | { | |
39 | u32 v; | |
40 | int c = 0; | |
41 | ||
42 | /* Write to the SOFTRESET bit */ | |
43 | omap_hwmod_softreset(oh); | |
44 | ||
45 | /* Enable the module's internal clocks */ | |
46 | v = omap_hwmod_read(oh, HDQ_CTRL_STATUS_OFFSET); | |
47 | v |= 1 << HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT; | |
48 | omap_hwmod_write(v, oh, HDQ_CTRL_STATUS_OFFSET); | |
49 | ||
50 | /* Poll on RESETDONE bit */ | |
51 | omap_test_timeout((omap_hwmod_read(oh, | |
52 | oh->class->sysc->syss_offs) | |
53 | & SYSS_RESETDONE_MASK), | |
54 | MAX_MODULE_SOFTRESET_WAIT, c); | |
55 | ||
56 | if (c == MAX_MODULE_SOFTRESET_WAIT) | |
3d0cb73e JP |
57 | pr_warn("%s: %s: softreset failed (waited %d usec)\n", |
58 | __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); | |
9e1b7498 PW |
59 | else |
60 | pr_debug("%s: %s: softreset in %d usec\n", __func__, | |
61 | oh->name, c); | |
62 | ||
63 | return 0; | |
64 | } |