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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 09:41:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 09:41:01 -0700
commitcdd3a354a05b0c33fe33ab11a0fb0838396cad19 (patch)
treeea2c87bbc2dc5865a97e73e201661d69937b45d5 /arch/arm/mach-omap2/hdq1w.c
parent813a95e5b4fa936bbde10ef89188932745dcd7f4 (diff)
parentada2e35defe6c6f0a986ec8147e47726fbd0e7b1 (diff)
Merge tag 'pm' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc power management changes from Olof Johansson: "Power management changes here are mostly for the omap platform, but also include cpuidle changes for ux500 and suspend/resume code for mmp." * tag 'pm' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (48 commits) ARM: OMAP2+: WDTIMER integration: fix !PM boot crash, disarm timer after hwmod reset ARM: OMAP2/3: hwmod data: Add 32k-sync timer data to hwmod database ARM: OMAP4: hwmod_data: Name the common irq for McBSP ports ARM: OMAP4: hwmod data: I2C: add flag for context restore ARM: OMAP3: hwmod_data: Rename the common irq for McBSP ports ARM: OMAP2xxx: hwmod data: add HDQ/1-wire hwmod ARM: OMAP3: hwmod data: add HDQ/1-wire hwmod ARM: OMAP2+: hwmod data: add HDQ/1-wire hwmod shared data ARM: OMAP2+: HDQ1W: add custom reset function ARM: OMAP2420: hwmod data: Add MMC hwmod data for 2420 arm: omap3: clockdomain data: Remove superfluous commas from gfx_sgx_3xxx_wkdeps[] ARM: OMAP2+: powerdomain: Get rid off duplicate pwrdm_clkdm_state_switch() API ARM: OMAP3: clock data: add clockdomain for HDQ functional clock ARM: OMAP3+: dpll: Configure autoidle mode only if it's supported ARM: OMAP2+: dmtimer: cleanup iclk usage ARM: OMAP4+: Add prm and cm base init function. ARM: OMAP2/3: Add idle_st bits for ST_32KSYNC timer to prcm-common header ARM: OMAP3: Fix CM register bit masks ARM: OMAP: clock: convert AM3517/3505 detection/flags to AM35xx ARM: OMAP3: clock data: treat all AM35x devices the same ...
Diffstat (limited to 'arch/arm/mach-omap2/hdq1w.c')
-rw-r--r--arch/arm/mach-omap2/hdq1w.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/hdq1w.c b/arch/arm/mach-omap2/hdq1w.c
new file mode 100644
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+++ b/arch/arm/mach-omap2/hdq1w.c
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+/*
+ * IP block integration code for the HDQ1W/1-wire IP block
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ * Paul Walmsley
+ *
+ * Based on the I2C reset code in arch/arm/mach-omap2/i2c.c by
+ * Avinash.H.M <avinashhm@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <plat/omap_hwmod.h>
+#include <plat/hdq1w.h>
+
+#include "common.h"
+
+/* Maximum microseconds to wait for OMAP module to softreset */
+#define MAX_MODULE_SOFTRESET_WAIT 10000
+
+/**
+ * omap_hdq1w_reset - reset the OMAP HDQ1W module
+ * @oh: struct omap_hwmod *
+ *
+ * OCP soft reset the HDQ1W IP block. Section 20.6.1.4 "HDQ1W/1-Wire
+ * Software Reset" of the OMAP34xx Technical Reference Manual Revision
+ * ZR (SWPU223R) does not include the rather important fact that, for
+ * the reset to succeed, the HDQ1W module's internal clock gate must be
+ * programmed to allow the clock to propagate to the rest of the
+ * module. In this sense, it's rather similar to the I2C custom reset
+ * function. Returns 0.
+ */
+int omap_hdq1w_reset(struct omap_hwmod *oh)
+{
+ u32 v;
+ int c = 0;
+
+ /* Write to the SOFTRESET bit */
+ omap_hwmod_softreset(oh);
+
+ /* Enable the module's internal clocks */
+ v = omap_hwmod_read(oh, HDQ_CTRL_STATUS_OFFSET);
+ v |= 1 << HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT;
+ omap_hwmod_write(v, oh, HDQ_CTRL_STATUS_OFFSET);
+
+ /* Poll on RESETDONE bit */
+ omap_test_timeout((omap_hwmod_read(oh,
+ oh->class->sysc->syss_offs)
+ & SYSS_RESETDONE_MASK),
+ MAX_MODULE_SOFTRESET_WAIT, c);
+
+ if (c == MAX_MODULE_SOFTRESET_WAIT)
+ pr_warning("%s: %s: softreset failed (waited %d usec)\n",
+ __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
+ else
+ pr_debug("%s: %s: softreset in %d usec\n", __func__,
+ oh->name, c);
+
+ return 0;
+}