projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 9e1b7498 PW |
1 | /* |
| 2 | * IP block integration code for the HDQ1W/1-wire IP block | |
| 3 | * | |
| 4 | * Copyright (C) 2012 Texas Instruments, Inc. | |
| 5 | * Paul Walmsley | |
| 6 | * | |
| 7 | * Based on the I2C reset code in arch/arm/mach-omap2/i2c.c by | |
| 8 | * Avinash.H.M <avinashhm@ti.com> | |
| 9 | * | |
| 10 | * This program is free software; you can redistribute it and/or | |
| 11 | * modify it under the terms of the GNU General Public License | |
| 12 | * version 2 as published by the Free Software Foundation. | |
| 13 | * | |
| 14 | * This program is distributed in the hope that it will be useful, but | |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 17 | * General Public License for more details. | |
| 18 | * | |
| 19 | * You should have received a copy of the GNU General Public License | |
| 20 | * along with this program; if not, write to the Free Software | |
| 21 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
| 22 | * 02110-1301 USA | |
| 23 | */ | |
| 24 | ||
| 96b1b29d PW |
25 | #include <linux/kernel.h> |
| 26 | #include <linux/init.h> | |
| 27 | #include <linux/err.h> | |
| 28 | #include <linux/platform_device.h> | |
| 29 | ||
| 2a296c8f | 30 | #include "omap_hwmod.h" |
| 25c7d49e | 31 | #include "omap_device.h" |
| a0b30ca5 | 32 | #include "hdq1w.h" |
| 9e1b7498 | 33 | |
| b13159af | 34 | #include "prm.h" |
| 9e1b7498 PW |
35 | #include "common.h" |
| 36 | ||
| 9e1b7498 PW |
37 | /** |
| 38 | * omap_hdq1w_reset - reset the OMAP HDQ1W module | |
| 39 | * @oh: struct omap_hwmod * | |
| 40 | * | |
| 41 | * OCP soft reset the HDQ1W IP block. Section 20.6.1.4 "HDQ1W/1-Wire | |
| 42 | * Software Reset" of the OMAP34xx Technical Reference Manual Revision | |
| 43 | * ZR (SWPU223R) does not include the rather important fact that, for | |
| 44 | * the reset to succeed, the HDQ1W module's internal clock gate must be | |
| 45 | * programmed to allow the clock to propagate to the rest of the | |
| 46 | * module. In this sense, it's rather similar to the I2C custom reset | |
| 47 | * function. Returns 0. | |
| 48 | */ | |
| 49 | int omap_hdq1w_reset(struct omap_hwmod *oh) | |
| 50 | { | |
| 51 | u32 v; | |
| 52 | int c = 0; | |
| 53 | ||
| 54 | /* Write to the SOFTRESET bit */ | |
| 55 | omap_hwmod_softreset(oh); | |
| 56 | ||
| 57 | /* Enable the module's internal clocks */ | |
| 58 | v = omap_hwmod_read(oh, HDQ_CTRL_STATUS_OFFSET); | |
| 59 | v |= 1 << HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT; | |
| 60 | omap_hwmod_write(v, oh, HDQ_CTRL_STATUS_OFFSET); | |
| 61 | ||
| 62 | /* Poll on RESETDONE bit */ | |
| 63 | omap_test_timeout((omap_hwmod_read(oh, | |
| 64 | oh->class->sysc->syss_offs) | |
| 65 | & SYSS_RESETDONE_MASK), | |
| 66 | MAX_MODULE_SOFTRESET_WAIT, c); | |
| 67 | ||
| 68 | if (c == MAX_MODULE_SOFTRESET_WAIT) | |
| 69 | pr_warning("%s: %s: softreset failed (waited %d usec)\n", | |
| 70 | __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); | |
| 71 | else | |
| 72 | pr_debug("%s: %s: softreset in %d usec\n", __func__, | |
| 73 | oh->name, c); | |
| 74 | ||
| 75 | return 0; | |
| 76 | } | |
| 96b1b29d PW |
77 | |
| 78 | static int __init omap_init_hdq(void) | |
| 79 | { | |
| 80 | int id = -1; | |
| 81 | struct platform_device *pdev; | |
| 82 | struct omap_hwmod *oh; | |
| 83 | char *oh_name = "hdq1w"; | |
| 84 | char *devname = "omap_hdq"; | |
| 85 | ||
| 86 | oh = omap_hwmod_lookup(oh_name); | |
| 87 | if (!oh) | |
| 88 | return 0; | |
| 89 | ||
| 90 | pdev = omap_device_build(devname, id, oh, NULL, 0, NULL, 0, 0); | |
| 91 | WARN(IS_ERR(pdev), "Can't build omap_device for %s:%s.\n", | |
| 92 | devname, oh->name); | |
| 93 | ||
| 94 | return 0; | |
| 95 | } | |
| 96 | arch_initcall(omap_init_hdq); |