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authorPaul Walmsley <paul@pwsan.com>2010-09-21 20:34:10 +0400
committerPaul Walmsley <paul@pwsan.com>2010-09-22 01:12:40 +0400
commitcf21405fd51b416f071edb546631a6ecd2112263 (patch)
treec443eb696bb2d4d564a520a1196bd76dd7349b0c /arch/arm/mach-omap2/prm2xxx_3xxx.c
parent0be1621a749907ada0101e4139a1f57168c5410b (diff)
downloadlinux-cf21405fd51b416f071edb546631a6ecd2112263.tar.xz
OMAP2/3: PRM: add module hard reset support
This patch adds hard-reset support for processor modules (e.g., DSP, IVA) on OMAP2/3 platforms. It's based on the OMAP4 hard-reset support that Benoît developed in the previous patch. This patch is a collaboration between Benoît Cousson <b-cousson@ti.com> and Paul Walmsley <paul@pwsan.com>. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Benoît Cousson <b-cousson@ti.com>
Diffstat (limited to 'arch/arm/mach-omap2/prm2xxx_3xxx.c')
-rw-r--r--arch/arm/mach-omap2/prm2xxx_3xxx.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
new file mode 100644
index 000000000000..421771eee450
--- /dev/null
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -0,0 +1,110 @@
+/*
+ * OMAP2/3 PRM module functions
+ *
+ * Copyright (C) 2010 Texas Instruments, Inc.
+ * Copyright (C) 2010 Nokia Corporation
+ * Benoît 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-24xx.h"
+#include "prm-regbits-34xx.h"
+
+/**
+ * omap2_prm_is_hardreset_asserted - read the HW reset line state of
+ * submodules contained in the hwmod module
+ * @prm_mod: PRM submodule base (e.g. CORE_MOD)
+ * @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 if called while running on a non-OMAP2/3 chip.
+ */
+int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift)
+{
+ if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
+ return -EINVAL;
+
+ return prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
+ (1 << shift));
+}
+
+/**
+ * omap2_prm_assert_hardreset - assert the HW reset line of a submodule
+ * @prm_mod: PRM submodule base (e.g. CORE_MOD)
+ * @shift: register bit shift corresponding to the reset line to assert
+ *
+ * Some IPs like dsp 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 omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
+{
+ u32 mask;
+
+ if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
+ return -EINVAL;
+
+ mask = 1 << shift;
+ prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);
+
+ return 0;
+}
+
+/**
+ * omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
+ * @prm_mod: PRM submodule base (e.g. CORE_MOD)
+ * @shift: register bit shift corresponding to the reset line to deassert
+ *
+ * Some IPs like dsp 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 omap2_prm_deassert_hardreset(s16 prm_mod, u8 shift)
+{
+ u32 mask;
+ int c;
+
+ if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
+ return -EINVAL;
+
+ mask = 1 << shift;
+
+ /* Check the current status to avoid de-asserting the line twice */
+ if (prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, mask) == 0)
+ return -EEXIST;
+
+ /* Clear the reset status by writing 1 to the status bit */
+ prm_rmw_mod_reg_bits(0xffffffff, mask, prm_mod, OMAP2_RM_RSTST);
+ /* de-assert the reset control line */
+ prm_rmw_mod_reg_bits(mask, 0, prm_mod, OMAP2_RM_RSTCTRL);
+ /* wait the status to be set */
+ omap_test_timeout(prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
+ mask),
+ MAX_MODULE_HARDRESET_WAIT, c);
+
+ return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
+}
+