OMAP4: hwmod: Replace RSTCTRL absolute address with offset macros

The RSTCTRL register was accessed using an absolute address.
The usage of hardcoded macros to calculate virtual address from physical
one should be avoided as much as possible.
The usage of an offset will allow future improvement like migration from
the current architecture code toward a module driver.

Update prm_xxx accessors, move definition to the proper header file and
update copyrights.
Change the s16 register offset parameter to u16.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: use '_prminst_' in function names that are part of the
 prminst44xx.c file]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

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;
+}