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 000000000000..a1ff918d9bed
--- /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
+ * 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-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;
+}
+