OMAP2+: hwmod: use status bit info for reset line

On OMAP2 and OMAP3 the reset ctrl shift doesn't match the
status bit, as it does on OMAP4, when handling the reset lines.

This patch adds a new member in the reset info structure, so now it
can be added as part of hwmod data, and checked accordingly for
OMAP2 or 3; otherwise, there could be cases when the shift masks
doesn't match both of the registers, and a successful reset might
throw an error message or vice versa.

Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>
[paul@pwsan.com: added a warning if st_shift used on OMAP4; renamed 'r'
 variable; improved some documentation]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 43 insertions, 32 deletions

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 2146d9aa507a..005264779f8d 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -972,25 +972,29 @@ static int _wait_target_ready(struct omap_hwmod *oh)
 }
 
 /**
- * _lookup_hardreset - return the register bit shift for this hwmod/reset line
+ * _lookup_hardreset - fill register bit info for this hwmod/reset line
  * @oh: struct omap_hwmod *
  * @name: name of the reset line in the context of this hwmod
+ * @ohri: struct omap_hwmod_rst_info * that this function will fill in
  *
  * Return the bit position of the reset line that match the
  * input name. Return -ENOENT if not found.
  */
-static u8 _lookup_hardreset(struct omap_hwmod *oh, const char *name)
+static u8 _lookup_hardreset(struct omap_hwmod *oh, const char *name,
+			    struct omap_hwmod_rst_info *ohri)
 {
 	int i;
 
 	for (i = 0; i < oh->rst_lines_cnt; i++) {
 		const char *rst_line = oh->rst_lines[i].name;
 		if (!strcmp(rst_line, name)) {
-			u8 shift = oh->rst_lines[i].rst_shift;
-			pr_debug("omap_hwmod: %s: _lookup_hardreset: %s: %d\n",
-				 oh->name, rst_line, shift);
+			ohri->rst_shift = oh->rst_lines[i].rst_shift;
+			ohri->st_shift = oh->rst_lines[i].st_shift;
+			pr_debug("omap_hwmod: %s: %s: %s: rst %d st %d\n",
+				 oh->name, __func__, rst_line, ohri->rst_shift,
+				 ohri->st_shift);
 
-			return shift;
+			return 0;
 		}
 	}
 
@@ -1009,21 +1013,22 @@ static u8 _lookup_hardreset(struct omap_hwmod *oh, const char *name)
  */
 static int _assert_hardreset(struct omap_hwmod *oh, const char *name)
 {
-	u8 shift;
+	struct omap_hwmod_rst_info ohri;
+	u8 ret;
 
 	if (!oh)
 		return -EINVAL;
 
-	shift = _lookup_hardreset(oh, name);
-	if (IS_ERR_VALUE(shift))
-		return shift;
+	ret = _lookup_hardreset(oh, name, &ohri);
+	if (IS_ERR_VALUE(ret))
+		return ret;
 
 	if (cpu_is_omap24xx() || cpu_is_omap34xx())
 		return omap2_prm_assert_hardreset(oh->prcm.omap2.module_offs,
-						  shift);
+						  ohri.rst_shift);
 	else if (cpu_is_omap44xx())
 		return omap4_prm_assert_hardreset(oh->prcm.omap4.rstctrl_reg,
-						  shift);
+						  ohri.rst_shift);
 	else
 		return -EINVAL;
 }
@@ -1040,29 +1045,34 @@ static int _assert_hardreset(struct omap_hwmod *oh, const char *name)
  */
 static int _deassert_hardreset(struct omap_hwmod *oh, const char *name)
 {
-	u8 shift;
-	int r;
+	struct omap_hwmod_rst_info ohri;
+	int ret;
 
 	if (!oh)
 		return -EINVAL;
 
-	shift = _lookup_hardreset(oh, name);
-	if (IS_ERR_VALUE(shift))
-		return shift;
+	ret = _lookup_hardreset(oh, name, &ohri);
+	if (IS_ERR_VALUE(ret))
+		return ret;
 
-	if (cpu_is_omap24xx() || cpu_is_omap34xx())
-		r = omap2_prm_deassert_hardreset(oh->prcm.omap2.module_offs,
-						 shift);
-	else if (cpu_is_omap44xx())
-		r = omap4_prm_deassert_hardreset(oh->prcm.omap4.rstctrl_reg,
-						 shift);
-	else
+	if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
+		ret = omap2_prm_deassert_hardreset(oh->prcm.omap2.module_offs,
+						   ohri.rst_shift,
+						   ohri.st_shift);
+	} else if (cpu_is_omap44xx()) {
+		if (ohri.st_shift)
+			pr_err("omap_hwmod: %s: %s: hwmod data error: OMAP4 does not support st_shift\n",
+			       oh->name, name);
+		ret = omap4_prm_deassert_hardreset(oh->prcm.omap4.rstctrl_reg,
+						   ohri.rst_shift);
+	} else {
 		return -EINVAL;
+	}
 
-	if (r == -EBUSY)
+	if (ret == -EBUSY)
 		pr_warning("omap_hwmod: %s: failed to hardreset\n", oh->name);
 
-	return r;
+	return ret;
 }
 
 /**
@@ -1075,21 +1085,22 @@ static int _deassert_hardreset(struct omap_hwmod *oh, const char *name)
  */
 static int _read_hardreset(struct omap_hwmod *oh, const char *name)
 {
-	u8 shift;
+	struct omap_hwmod_rst_info ohri;
+	u8 ret;
 
 	if (!oh)
 		return -EINVAL;
 
-	shift = _lookup_hardreset(oh, name);
-	if (IS_ERR_VALUE(shift))
-		return shift;
+	ret = _lookup_hardreset(oh, name, &ohri);
+	if (IS_ERR_VALUE(ret))
+		return ret;
 
 	if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
 		return omap2_prm_is_hardreset_asserted(oh->prcm.omap2.module_offs,
-						       shift);
+						       ohri.st_shift);
 	} else if (cpu_is_omap44xx()) {
 		return omap4_prm_is_hardreset_asserted(oh->prcm.omap4.rstctrl_reg,
-						       shift);
+						       ohri.rst_shift);
 	} else {
 		return -EINVAL;
 	}