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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 13:46:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 13:46:56 -0700
commit7b6181e06841f5ad15c4ff708b967b4db65a64de (patch)
treebdfcf5b74b692f76581156e452d268b64c795200 /arch/arm/mach-omap2/prm44xx.c
parent72e58063d63c5f0a7bf65312f1e3a5ed9bb5c2ff (diff)
parentbc487fb341af05120bccb9f59ce76302391dcc77 (diff)
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Merge branch 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (163 commits) omap: complete removal of machine_desc.io_pg_offst and .phys_io omap: UART: fix wakeup registers for OMAP24xx UART2 omap: Fix spotty MMC voltages ASoC: OMAP4: MCPDM: Remove unnecessary include of plat/control.h serial: omap-serial: fix signess error OMAP3: DMA: Errata i541: sDMA FIFO draining does not finish omap: dma: Fix buffering disable bit setting for omap24xx omap: serial: Fix the boot-up crash/reboot without CONFIG_PM OMAP3: PM: fix scratchpad memory accesses for off-mode omap4: pandaboard: enable the ehci port on pandaboard omap4: pandaboard: Fix the init if CONFIG_MMC_OMAP_HS is not set omap4: pandaboard: remove unused hsmmc definition OMAP: McBSP: Remove null omap44xx ops comment OMAP: McBSP: Swap CLKS source definition OMAP: McBSP: Fix CLKR and FSR signal muxing OMAP2+: clock: reduce the amount of standard debugging while disabling unused clocks OMAP: control: move plat-omap/control.h to mach-omap2/control.h OMAP: split plat-omap/common.c OMAP: McBSP: implement functional clock switching via clock framework OMAP: McBSP: implement McBSP CLKR and FSR signal muxing via mach-omap2/mcbsp.c ... Fixed up trivial conflicts in arch/arm/mach-omap2/ {board-zoom-peripherals.c,devices.c} as per Tony
Diffstat (limited to 'arch/arm/mach-omap2/prm44xx.c')
-rw-r--r--arch/arm/mach-omap2/prm44xx.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
new file mode 100644
index 0000000..a1ff918
--- /dev/null
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -0,0 +1,116 @@
+/*
+ * OMAP4 PRM module functions
+ *
+ * Copyright (C) 2010 Texas Instruments, Inc.
+ * Copyright (C) 2010 Nokia Corporation
+ * BenoƮt Cousson
+ * Paul Walmsley
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+
+#include <plat/common.h>
+#include <plat/cpu.h>
+#include <plat/prcm.h>
+
+#include "prm.h"
+#include "prm-regbits-44xx.h"
+
+/*
+ * Address offset (in bytes) between the reset control and the reset
+ * status registers: 4 bytes on OMAP4
+ */
+#define OMAP4_RST_CTRL_ST_OFFSET 4
+
+/**
+ * omap4_prm_is_hardreset_asserted - read the HW reset line state of
+ * submodules contained in the hwmod module
+ * @rstctrl_reg: RM_RSTCTRL register address for this module
+ * @shift: register bit shift corresponding to the reset line to check
+ *
+ * Returns 1 if the (sub)module hardreset line is currently asserted,
+ * 0 if the (sub)module hardreset line is not currently asserted, or
+ * -EINVAL upon parameter error.
+ */
+int omap4_prm_is_hardreset_asserted(void __iomem *rstctrl_reg, u8 shift)
+{
+ if (!cpu_is_omap44xx() || !rstctrl_reg)
+ return -EINVAL;
+
+ return omap4_prm_read_bits_shift(rstctrl_reg, (1 << shift));
+}
+
+/**
+ * omap4_prm_assert_hardreset - assert the HW reset line of a submodule
+ * @rstctrl_reg: RM_RSTCTRL register address for this module
+ * @shift: register bit shift corresponding to the reset line to assert
+ *
+ * Some IPs like dsp, ipu or iva contain processors that require an HW
+ * reset line to be asserted / deasserted in order to fully enable the
+ * IP. These modules may have multiple hard-reset lines that reset
+ * different 'submodules' inside the IP block. This function will
+ * place the submodule into reset. Returns 0 upon success or -EINVAL
+ * upon an argument error.
+ */
+int omap4_prm_assert_hardreset(void __iomem *rstctrl_reg, u8 shift)
+{
+ u32 mask;
+
+ if (!cpu_is_omap44xx() || !rstctrl_reg)
+ return -EINVAL;
+
+ mask = 1 << shift;
+ omap4_prm_rmw_reg_bits(mask, mask, rstctrl_reg);
+
+ return 0;
+}
+
+/**
+ * omap4_prm_deassert_hardreset - deassert a submodule hardreset line and wait
+ * @rstctrl_reg: RM_RSTCTRL register address for this module
+ * @shift: register bit shift corresponding to the reset line to deassert
+ *
+ * Some IPs like dsp, ipu or iva contain processors that require an HW
+ * reset line to be asserted / deasserted in order to fully enable the
+ * IP. These modules may have multiple hard-reset lines that reset
+ * different 'submodules' inside the IP block. This function will
+ * take the submodule out of reset and wait until the PRCM indicates
+ * that the reset has completed before returning. Returns 0 upon success or
+ * -EINVAL upon an argument error, -EEXIST if the submodule was already out
+ * of reset, or -EBUSY if the submodule did not exit reset promptly.
+ */
+int omap4_prm_deassert_hardreset(void __iomem *rstctrl_reg, u8 shift)
+{
+ u32 mask;
+ void __iomem *rstst_reg;
+ int c;
+
+ if (!cpu_is_omap44xx() || !rstctrl_reg)
+ return -EINVAL;
+
+ rstst_reg = rstctrl_reg + OMAP4_RST_CTRL_ST_OFFSET;
+
+ mask = 1 << shift;
+
+ /* Check the current status to avoid de-asserting the line twice */
+ if (omap4_prm_read_bits_shift(rstctrl_reg, mask) == 0)
+ return -EEXIST;
+
+ /* Clear the reset status by writing 1 to the status bit */
+ omap4_prm_rmw_reg_bits(0xffffffff, mask, rstst_reg);
+ /* de-assert the reset control line */
+ omap4_prm_rmw_reg_bits(mask, 0, rstctrl_reg);
+ /* wait the status to be set */
+ omap_test_timeout(omap4_prm_read_bits_shift(rstst_reg, mask),
+ MAX_MODULE_HARDRESET_WAIT, c);
+
+ return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
+}
+
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