From: omar ramirez <omar.rami...@ti.com>

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.rami...@ti.com>
[p...@pwsan.com: added a warning if st_shift used on OMAP4; renamed 'r'
 variable; improved some documentation]
Signed-off-by: Paul Walmsley <p...@pwsan.com>
---
 arch/arm/mach-omap2/omap_hwmod.c             |   75 +++++++++++++++-----------
 arch/arm/mach-omap2/prm2xxx_3xxx.c           |   18 +++---
 arch/arm/mach-omap2/prm2xxx_3xxx.h           |    5 +-
 arch/arm/plat-omap/include/plat/omap_hwmod.h |    2 +
 4 files changed, 58 insertions(+), 42 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 671f871..b0238e1 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;
        }
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c 
b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index ec03625..051213f 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -118,7 +118,8 @@ int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
 /**
  * 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
+ * @rst_shift: register bit shift corresponding to the reset line to deassert
+ * @st_shift: register bit shift for the status of the deasserted submodule
  *
  * Some IPs like dsp or iva contain processors that require an HW
  * reset line to be asserted / deasserted in order to fully enable the
@@ -129,27 +130,28 @@ int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
  * -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)
+int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 st_shift)
 {
-       u32 mask;
+       u32 rst, st;
        int c;
 
        if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
                return -EINVAL;
 
-       mask = 1 << shift;
+       rst = 1 << rst_shift;
+       st = 1 << st_shift;
 
        /* Check the current status to avoid de-asserting the line twice */
-       if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, mask) == 0)
+       if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, rst) == 0)
                return -EEXIST;
 
        /* Clear the reset status by writing 1 to the status bit */
-       omap2_prm_rmw_mod_reg_bits(0xffffffff, mask, prm_mod, OMAP2_RM_RSTST);
+       omap2_prm_rmw_mod_reg_bits(0xffffffff, st, prm_mod, OMAP2_RM_RSTST);
        /* de-assert the reset control line */
-       omap2_prm_rmw_mod_reg_bits(mask, 0, prm_mod, OMAP2_RM_RSTCTRL);
+       omap2_prm_rmw_mod_reg_bits(rst, 0, prm_mod, OMAP2_RM_RSTCTRL);
        /* wait the status to be set */
        omap_test_timeout(omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
-                                                 mask),
+                                                 st),
                          MAX_MODULE_HARDRESET_WAIT, c);
 
        return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.h 
b/arch/arm/mach-omap2/prm2xxx_3xxx.h
index 49654c8..a1fc62a 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.h
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.h
@@ -282,7 +282,8 @@ static inline int omap2_prm_assert_hardreset(s16 prm_mod, 
u8 shift)
                "not suppose to be used on omap4\n");
        return 0;
 }
-static inline int omap2_prm_deassert_hardreset(s16 prm_mod, u8 shift)
+static inline int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift,
+                                               u8 st_shift)
 {
        WARN(1, "prm: omap2xxx/omap3xxx specific function and "
                "not suppose to be used on omap4\n");
@@ -300,7 +301,7 @@ extern u32 omap2_prm_read_mod_bits_shift(s16 domain, s16 
idx, u32 mask);
 /* These omap2_ PRM functions apply to both OMAP2 and 3 */
 extern int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift);
 extern int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift);
-extern int omap2_prm_deassert_hardreset(s16 prm_mod, u8 shift);
+extern int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 
st_shift);
 
 #endif /* CONFIG_ARCH_OMAP4 */
 #endif
diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h 
b/arch/arm/plat-omap/include/plat/omap_hwmod.h
index c61e126..867e2e8 100644
--- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
+++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
@@ -124,6 +124,7 @@ struct omap_hwmod_dma_info {
  * struct omap_hwmod_rst_info - IPs reset lines use by hwmod
  * @name: name of the reset line (module local name)
  * @rst_shift: Offset of the reset bit
+ * @st_shift: Offset of the reset status bit (OMAP2/3 only)
  *
  * @name should be something short, e.g., "cpu0" or "rst". It is defined
  * locally to the hwmod.
@@ -131,6 +132,7 @@ struct omap_hwmod_dma_info {
 struct omap_hwmod_rst_info {
        const char      *name;
        u8              rst_shift;
+       u8              st_shift;
 };
 
 /**


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