ARM: OMAP2+: CM/clock: convert _omap2_module_wait_ready() to use SoC-independent CM functions

Convert the OMAP clock code's _omap2_module_wait_ready() to use
SoC-independent CM functions that are provided by the CM code, rather
than using a deprecated function from mach-omap2/prcm.c.

This facilitates the future conversion of the CM code to a driver, and
also removes a mach-omap2/prcm.c user.  mach-omap2/prcm.c will be removed
by a subsequent patch.

Some modules have IDLEST registers that aren't in the CM module, such
as the AM3517 IDLEST bits.  So we also need a fallback function for
these non-CM odd cases.  Create a temporary one in mach-omap2/clock.c,
intended to exist until the SCM drivers are ready.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>

8 files changed, 257 insertions, 4 deletions

diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 9205ea7d8dde..2fe57d65d0f1 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -33,10 +33,18 @@
 #include "soc.h"
 #include "clockdomain.h"
 #include "clock.h"
+#include "cm.h"
 #include "cm2xxx.h"
 #include "cm3xxx.h"
 #include "cm-regbits-24xx.h"
 #include "cm-regbits-34xx.h"
+#include "common.h"
+
+/*
+ * MAX_MODULE_ENABLE_WAIT: maximum of number of microseconds to wait
+ * for a module to indicate that it is no longer in idle
+ */
+#define MAX_MODULE_ENABLE_WAIT          100000
 
 u16 cpu_mask;
 
@@ -58,6 +66,40 @@ static DEFINE_SPINLOCK(clockfw_lock);
 
 /* Private functions */
 
+
+/**
+ * _wait_idlest_generic - wait for a module to leave the idle state
+ * @reg: virtual address of module IDLEST register
+ * @mask: value to mask against to determine if the module is active
+ * @idlest: idle state indicator (0 or 1) for the clock
+ * @name: name of the clock (for printk)
+ *
+ * Wait for a module to leave idle, where its idle-status register is
+ * not inside the CM module.  Returns 1 if the module left idle
+ * promptly, or 0 if the module did not leave idle before the timeout
+ * elapsed.  XXX Deprecated - should be moved into drivers for the
+ * individual IP block that the IDLEST register exists in.
+ */
+static int _wait_idlest_generic(void __iomem *reg, u32 mask, u8 idlest,
+                                const char *name)
+{
+        int i = 0, ena = 0;
+
+        ena = (idlest) ? 0 : mask;
+
+        omap_test_timeout(((__raw_readl(reg) & mask) == ena),
+                          MAX_MODULE_ENABLE_WAIT, i);
+
+        if (i < MAX_MODULE_ENABLE_WAIT)
+                pr_debug("omap clock: module associated with clock %s ready after %d loops\n",
+                         name, i);
+        else
+                pr_err("omap clock: module associated with clock %s didn't enable in %d tries\n",
+                       name, MAX_MODULE_ENABLE_WAIT);
+
+        return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
+};
+
 /**
  * _omap2_module_wait_ready - wait for an OMAP module to leave IDLE
  * @clk: struct clk * belonging to the module
@@ -71,7 +113,9 @@ static DEFINE_SPINLOCK(clockfw_lock);
 static void _omap2_module_wait_ready(struct clk *clk)
 {
         void __iomem *companion_reg, *idlest_reg;
-        u8 other_bit, idlest_bit, idlest_val;
+        u8 other_bit, idlest_bit, idlest_val, idlest_reg_id;
+        s16 prcm_mod;
+        int r;
 
         /* Not all modules have multiple clocks that their IDLEST depends on */
         if (clk->ops->find_companion) {
@@ -82,8 +126,14 @@ static void _omap2_module_wait_ready(struct clk *clk)
 
         clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit, &idlest_val);
 
-        omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), idlest_val,
-                             __clk_get_name(clk));
+        r = cm_split_idlest_reg(idlest_reg, &prcm_mod, &idlest_reg_id);
+        if (r) {
+                /* IDLEST register not in the CM module */
+                _wait_idlest_generic(idlest_reg, (1 << idlest_bit), idlest_val,
+                                     clk->name);
+        } else {
+                cm_wait_module_ready(prcm_mod, idlest_reg_id, idlest_bit);
+        };
 }
 
 /* Public functions */
diff --git a/arch/arm/mach-omap2/cm.h b/arch/arm/mach-omap2/cm.h
index b3cee913dd67..e419ecb7cce4 100644
--- a/arch/arm/mach-omap2/cm.h
+++ b/arch/arm/mach-omap2/cm.h
@@ -37,8 +37,18 @@
 
 /**
  * struct cm_ll_data - fn ptrs to per-SoC CM function implementations
+ * @split_idlest_reg: ptr to the SoC CM-specific split_idlest_reg impl
+ * @wait_module_ready: ptr to the SoC CM-specific wait_module_ready impl
  */
-struct cm_ll_data {};
+struct cm_ll_data {
+        int (*split_idlest_reg)(void __iomem *idlest_reg, s16 *prcm_inst,
+                                u8 *idlest_reg_id);
+        int (*wait_module_ready)(s16 prcm_mod, u8 idlest_id, u8 idlest_shift);
+};
+
+extern int cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
+                               u8 *idlest_reg_id);
+extern int cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift);
 
 extern int cm_register(struct cm_ll_data *cld);
 extern int cm_unregister(struct cm_ll_data *cld);
diff --git a/arch/arm/mach-omap2/cm2xxx.c b/arch/arm/mach-omap2/cm2xxx.c
index e96cd7041b66..db650690e9d0 100644
--- a/arch/arm/mach-omap2/cm2xxx.c
+++ b/arch/arm/mach-omap2/cm2xxx.c
@@ -198,6 +198,43 @@ void omap2xxx_cm_apll96_disable(void)
         _omap2xxx_apll_disable(OMAP24XX_EN_96M_PLL_SHIFT);
 }
 
+/**
+ * omap2xxx_cm_split_idlest_reg - split CM_IDLEST reg addr into its components
+ * @idlest_reg: CM_IDLEST* virtual address
+ * @prcm_inst: pointer to an s16 to return the PRCM instance offset
+ * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
+ *
+ * XXX This function is only needed until absolute register addresses are
+ * removed from the OMAP struct clk records.
+ */
+int omap2xxx_cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
+                                 u8 *idlest_reg_id)
+{
+        unsigned long offs;
+        u8 idlest_offs;
+        int i;
+
+        if (idlest_reg < cm_base || idlest_reg > (cm_base + 0x0fff))
+                return -EINVAL;
+
+        idlest_offs = (unsigned long)idlest_reg & 0xff;
+        for (i = 0; i < ARRAY_SIZE(omap2xxx_cm_idlest_offs); i++) {
+                if (idlest_offs == omap2xxx_cm_idlest_offs[i]) {
+                        *idlest_reg_id = i + 1;
+                        break;
+                }
+        }
+
+        if (i == ARRAY_SIZE(omap2xxx_cm_idlest_offs))
+                return -EINVAL;
+
+        offs = idlest_reg - cm_base;
+        offs &= 0xff00;
+        *prcm_inst = offs;
+
+        return 0;
+}
+
 /*
  *
  */
@@ -314,3 +351,31 @@ struct clkdm_ops omap2_clkdm_operations = {
         .clkdm_clk_enable       = omap2xxx_clkdm_clk_enable,
         .clkdm_clk_disable      = omap2xxx_clkdm_clk_disable,
 };
+
+/*
+ *
+ */
+
+static struct cm_ll_data omap2xxx_cm_ll_data = {
+        .split_idlest_reg       = &omap2xxx_cm_split_idlest_reg,
+        .wait_module_ready      = &omap2xxx_cm_wait_module_ready,
+};
+
+int __init omap2xxx_cm_init(void)
+{
+        if (!cpu_is_omap24xx())
+                return 0;
+
+        return cm_register(&omap2xxx_cm_ll_data);
+}
+
+static void __exit omap2xxx_cm_exit(void)
+{
+        if (!cpu_is_omap24xx())
+                return;
+
+        /* Should never happen */
+        WARN(cm_unregister(&omap2xxx_cm_ll_data),
+             "%s: cm_ll_data function pointer mismatch\n", __func__);
+}
+__exitcall(omap2xxx_cm_exit);
diff --git a/arch/arm/mach-omap2/cm2xxx.h b/arch/arm/mach-omap2/cm2xxx.h
index bce3c4be6d1f..4cbb39b051d2 100644
--- a/arch/arm/mach-omap2/cm2xxx.h
+++ b/arch/arm/mach-omap2/cm2xxx.h
@@ -60,6 +60,10 @@ extern void omap2xxx_cm_set_apll96_auto_low_power_stop(void);
 extern bool omap2xxx_cm_is_clkdm_in_hwsup(s16 module, u32 mask);
 extern int omap2xxx_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id,
                                          u8 idlest_shift);
+extern int omap2xxx_cm_split_idlest_reg(void __iomem *idlest_reg,
+                                        s16 *prcm_inst, u8 *idlest_reg_id);
+
+extern int __init omap2xxx_cm_init(void);
 
 #endif
 
diff --git a/arch/arm/mach-omap2/cm3xxx.c b/arch/arm/mach-omap2/cm3xxx.c
index 8b03ec2f4394..c2086f2e86b6 100644
--- a/arch/arm/mach-omap2/cm3xxx.c
+++ b/arch/arm/mach-omap2/cm3xxx.c
@@ -110,6 +110,44 @@ int omap3xxx_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 }
 
+/**
+ * omap3xxx_cm_split_idlest_reg - split CM_IDLEST reg addr into its components
+ * @idlest_reg: CM_IDLEST* virtual address
+ * @prcm_inst: pointer to an s16 to return the PRCM instance offset
+ * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
+ *
+ * XXX This function is only needed until absolute register addresses are
+ * removed from the OMAP struct clk records.
+ */
+int omap3xxx_cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
+                                 u8 *idlest_reg_id)
+{
+        unsigned long offs;
+        u8 idlest_offs;
+        int i;
+
+        if (idlest_reg < (cm_base + OMAP3430_IVA2_MOD) ||
+            idlest_reg > (cm_base + 0x1ffff))
+                return -EINVAL;
+
+        idlest_offs = (unsigned long)idlest_reg & 0xff;
+        for (i = 0; i < ARRAY_SIZE(omap3xxx_cm_idlest_offs); i++) {
+                if (idlest_offs == omap3xxx_cm_idlest_offs[i]) {
+                        *idlest_reg_id = i + 1;
+                        break;
+                }
+        }
+
+        if (i == ARRAY_SIZE(omap3xxx_cm_idlest_offs))
+                return -EINVAL;
+
+        offs = idlest_reg - cm_base;
+        offs &= 0xff00;
+        *prcm_inst = offs;
+
+        return 0;
+}
+
 /* Clockdomain low-level operations */
 
 static int omap3xxx_clkdm_add_sleepdep(struct clockdomain *clkdm1,
@@ -597,3 +635,31 @@ void omap3_cm_restore_context(void)
         omap2_cm_write_mod_reg(cm_context.cm_clkout_ctrl, OMAP3430_CCR_MOD,
                                OMAP3_CM_CLKOUT_CTRL_OFFSET);
 }
+
+/*
+ *
+ */
+
+static struct cm_ll_data omap3xxx_cm_ll_data = {
+        .split_idlest_reg       = &omap3xxx_cm_split_idlest_reg,
+        .wait_module_ready      = &omap3xxx_cm_wait_module_ready,
+};
+
+int __init omap3xxx_cm_init(void)
+{
+        if (!cpu_is_omap34xx())
+                return 0;
+
+        return cm_register(&omap3xxx_cm_ll_data);
+}
+
+static void __exit omap3xxx_cm_exit(void)
+{
+        if (!cpu_is_omap34xx())
+                return;
+
+        /* Should never happen */
+        WARN(cm_unregister(&omap3xxx_cm_ll_data),
+             "%s: cm_ll_data function pointer mismatch\n", __func__);
+}
+__exitcall(omap3xxx_cm_exit);
diff --git a/arch/arm/mach-omap2/cm3xxx.h b/arch/arm/mach-omap2/cm3xxx.h
index 4a6ac812edf4..e8e146f4a43f 100644
--- a/arch/arm/mach-omap2/cm3xxx.h
+++ b/arch/arm/mach-omap2/cm3xxx.h
@@ -78,9 +78,14 @@ extern bool omap3xxx_cm_is_clkdm_in_hwsup(s16 module, u32 mask);
 extern int omap3xxx_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id,
                                          u8 idlest_shift);
 
+extern int omap3xxx_cm_split_idlest_reg(void __iomem *idlest_reg,
+                                        s16 *prcm_inst, u8 *idlest_reg_id);
+
 extern void omap3_cm_save_context(void);
 extern void omap3_cm_restore_context(void);
 
+extern int __init omap3xxx_cm_init(void);
+
 #endif
 
 #endif
diff --git a/arch/arm/mach-omap2/cm_common.c b/arch/arm/mach-omap2/cm_common.c
index 3246cef151dc..561969bb511e 100644
--- a/arch/arm/mach-omap2/cm_common.c
+++ b/arch/arm/mach-omap2/cm_common.c
@@ -26,6 +26,54 @@ static struct cm_ll_data null_cm_ll_data;
 static struct cm_ll_data *cm_ll_data = &null_cm_ll_data;
 
 /**
+ * cm_split_idlest_reg - split CM_IDLEST reg addr into its components
+ * @idlest_reg: CM_IDLEST* virtual address
+ * @prcm_inst: pointer to an s16 to return the PRCM instance offset
+ * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
+ *
+ * Given an absolute CM_IDLEST register address @idlest_reg, passes
+ * the PRCM instance offset and IDLEST register ID back to the caller
+ * via the @prcm_inst and @idlest_reg_id.  Returns -EINVAL upon error,
+ * or 0 upon success.  XXX This function is only needed until absolute
+ * register addresses are removed from the OMAP struct clk records.
+ */
+int cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
+                        u8 *idlest_reg_id)
+{
+        if (!cm_ll_data->split_idlest_reg) {
+                WARN_ONCE(1, "cm: %s: no low-level function defined\n",
+                          __func__);
+                return -EINVAL;
+        }
+
+        return cm_ll_data->split_idlest_reg(idlest_reg, prcm_inst,
+                                           idlest_reg_id);
+}
+
+/**
+ * cm_wait_module_ready - wait for a module to leave idle or standby
+ * @prcm_mod: PRCM module offset
+ * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
+ * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
+ *
+ * Wait for the PRCM to indicate that the module identified by
+ * (@prcm_mod, @idlest_id, @idlest_shift) is clocked.  Return 0 upon
+ * success, -EBUSY if the module doesn't enable in time, or -EINVAL if
+ * no per-SoC wait_module_ready() function pointer has been registered
+ * or if the idlest register is unknown on the SoC.
+ */
+int cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
+{
+        if (!cm_ll_data->wait_module_ready) {
+                WARN_ONCE(1, "cm: %s: no low-level function defined\n",
+                          __func__);
+                return -EINVAL;
+        }
+
+        return cm_ll_data->wait_module_ready(prcm_mod, idlest_id, idlest_shift);
+}
+
+/**
  * cm_register - register per-SoC low-level data with the CM
  * @cld: low-level per-SoC OMAP CM data & function pointers to register
  *
diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index a204b7055007..772dc7e05c88 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -45,6 +45,8 @@
 #include "sdrc.h"
 #include "control.h"
 #include "serial.h"
+#include "cm2xxx.h"
+#include "cm3xxx.h"
 
 /*
  * The machine specific code may provide the extra mapping besides the
@@ -388,6 +390,7 @@ void __init omap2420_init_early(void)
                                OMAP2_L4_IO_ADDRESS(OMAP2420_CM_BASE),
                                NULL, NULL);
         omap2xxx_check_revision();
+        omap2xxx_cm_init();
         omap_common_init_early();
         omap2xxx_voltagedomains_init();
         omap242x_powerdomains_init();
@@ -417,6 +420,7 @@ void __init omap2430_init_early(void)
                                OMAP2_L4_IO_ADDRESS(OMAP2430_CM_BASE),
                                NULL, NULL);
         omap2xxx_check_revision();
+        omap2xxx_cm_init();
         omap_common_init_early();
         omap2xxx_voltagedomains_init();
         omap243x_powerdomains_init();
@@ -451,6 +455,7 @@ void __init omap3_init_early(void)
                                NULL, NULL);
         omap3xxx_check_revision();
         omap3xxx_check_features();
+        omap3xxx_cm_init();
         omap_common_init_early();
         omap3xxx_voltagedomains_init();
         omap3xxx_powerdomains_init();