1 files changed, 92 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/prminst44xx.c b/arch/arm/mach-omap2/prminst44xx.c
index a30324297278..35e02aac1de9 100644
--- a/arch/arm/mach-omap2/prminst44xx.c
+++ b/arch/arm/mach-omap2/prminst44xx.c
@@ -2,6 +2,7 @@
  * OMAP4 PRM instance functions
  *
  * Copyright (C) 2009 Nokia Corporation
+ * Copyright (C) 2011 Texas Instruments, Inc.
  * Paul Walmsley
  *
  * This program is free software; you can redistribute it and/or modify
@@ -53,7 +54,7 @@ void omap4_prminst_write_inst_reg(u32 val, u8 part, s16 inst, u16 idx)
 
 /* Read-modify-write a register in PRM. Caller must lock */
 u32 omap4_prminst_rmw_inst_reg_bits(u32 mask, u32 bits, u8 part, s16 inst,
-                                   s16 idx)
+                                    u16 idx)
 {
         u32 v;
 
@@ -64,3 +65,93 @@ u32 omap4_prminst_rmw_inst_reg_bits(u32 mask, u32 bits, u8 part, s16 inst,
 
         return v;
 }
+
+/*
+ * 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_prminst_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_prminst_is_hardreset_asserted(u8 shift, u8 part, s16 inst,
+                                        u16 rstctrl_offs)
+{
+        u32 v;
+
+        v = omap4_prminst_read_inst_reg(part, inst, rstctrl_offs);
+        v &= 1 << shift;
+        v >>= shift;
+
+        return v;
+}
+
+/**
+ * omap4_prminst_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_prminst_assert_hardreset(u8 shift, u8 part, s16 inst,
+                                   u16 rstctrl_offs)
+{
+        u32 mask = 1 << shift;
+
+        omap4_prminst_rmw_inst_reg_bits(mask, mask, part, inst, rstctrl_offs);
+
+        return 0;
+}
+
+/**
+ * omap4_prminst_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_prminst_deassert_hardreset(u8 shift, u8 part, s16 inst,
+                                     u16 rstctrl_offs)
+{
+        int c;
+        u32 mask = 1 << shift;
+        u16 rstst_offs = rstctrl_offs + OMAP4_RST_CTRL_ST_OFFSET;
+
+        /* Check the current status to avoid de-asserting the line twice */
+        if (omap4_prminst_is_hardreset_asserted(shift, part, inst,
+                                                rstctrl_offs) == 0)
+                return -EEXIST;
+
+        /* Clear the reset status by writing 1 to the status bit */
+        omap4_prminst_rmw_inst_reg_bits(0xffffffff, mask, part, inst,
+                                        rstst_offs);
+        /* de-assert the reset control line */
+        omap4_prminst_rmw_inst_reg_bits(mask, 0, part, inst, rstctrl_offs);
+        /* wait the status to be set */
+        omap_test_timeout(omap4_prminst_is_hardreset_asserted(shift, part, inst,
+                                                              rstst_offs),
+                          MAX_MODULE_HARDRESET_WAIT, c);
+
+        return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
+}