davinci: major rework of clock, PLL, PSC infrastructure

This is a significant rework of the low-level clock, PLL and Power
Sleep Controller (PSC) implementation for the DaVinci family.  The
primary goal is to have better modeling if the hardware clocks and
features with the aim of DVFS functionality.

Highlights:
- model PLLs and all PLL-derived clocks
- model parent/child relationships of PLLs and clocks
- convert to new clkdev layer
- view clock frequency and refcount via /proc/davinci_clocks

Special thanks to significant contributions and testing by David
Brownell.

Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

10 files changed, 402 insertions, 234 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bb57f35e7683..cfd99649ad85 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -586,6 +586,7 @@ config ARCH_DAVINCI
         select HAVE_CLK
         select ZONE_DMA
         select HAVE_IDE
+        select COMMON_CLKDEV
         help
           Support for TI's DaVinci platform.
 
diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index bac988e7a4c3..af886734c73b 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -18,6 +18,18 @@ config MACH_DAVINCI_EVM
           Configure this option to specify the whether the board used
           for development is a DaVinci EVM
 
+config DAVINCI_RESET_CLOCKS
+        bool "Reset unused clocks during boot"
+        depends on ARCH_DAVINCI
+        help
+          Say Y if you want to reset unused clocks during boot.
+          This option saves power, but assumes all drivers are
+          using the clock framework. Broken drivers that do not
+          yet use clock framework may not work with this option.
+          If you are booting from another operating system, you
+          probably do not want this option enabled until your
+          device drivers work properly.
+
 endmenu
 
 endif
diff --git a/arch/arm/mach-davinci/board-evm.c b/arch/arm/mach-davinci/board-evm.c
index 0b97a528902b..1b745c39d891 100644
--- a/arch/arm/mach-davinci/board-evm.c
+++ b/arch/arm/mach-davinci/board-evm.c
@@ -406,8 +406,6 @@ davinci_evm_map_io(void)
 
 static __init void davinci_evm_init(void)
 {
-        davinci_psc_init();
-
 #if defined(CONFIG_BLK_DEV_PALMCHIP_BK3710) || \
     defined(CONFIG_BLK_DEV_PALMCHIP_BK3710_MODULE)
 #if defined(CONFIG_MTD_PHYSMAP) || \
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index abb92b7eca0c..f0baaa15a57e 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -1,7 +1,8 @@
 /*
- * TI DaVinci clock config file
+ * Clock and PLL control for DaVinci devices
  *
- * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2006-2007 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -13,6 +14,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/errno.h>
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
@@ -21,98 +23,50 @@
 #include <mach/hardware.h>
 
 #include <mach/psc.h>
+#include <mach/cputype.h>
 #include "clock.h"
 
-/* PLL/Reset register offsets */
-#define PLLM            0x110
-
 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 static DEFINE_SPINLOCK(clockfw_lock);
 
-static unsigned int commonrate;
-static unsigned int armrate;
-static unsigned int fixedrate = 27000000;       /* 27 MHZ */
-
-extern void davinci_psc_config(unsigned int domain, unsigned int id, char enable);
-
-/*
- * Returns a clock. Note that we first try to use device id on the bus
- * and clock name. If this fails, we try to use clock name only.
- */
-struct clk *clk_get(struct device *dev, const char *id)
+static unsigned psc_domain(struct clk *clk)
 {
-        struct clk *p, *clk = ERR_PTR(-ENOENT);
-        int idno;
-
-        if (dev == NULL || dev->bus != &platform_bus_type)
-                idno = -1;
-        else
-                idno = to_platform_device(dev)->id;
-
-        mutex_lock(&clocks_mutex);
-
-        list_for_each_entry(p, &clocks, node) {
-                if (p->id == idno &&
-                    strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
-                        clk = p;
-                        goto found;
-                }
-        }
-
-        list_for_each_entry(p, &clocks, node) {
-                if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
-                        clk = p;
-                        break;
-                }
-        }
-
-found:
-        mutex_unlock(&clocks_mutex);
-
-        return clk;
+        return (clk->flags & PSC_DSP)
+                ? DAVINCI_GPSC_DSPDOMAIN
+                : DAVINCI_GPSC_ARMDOMAIN;
 }
-EXPORT_SYMBOL(clk_get);
 
-void clk_put(struct clk *clk)
+static void __clk_enable(struct clk *clk)
 {
-        if (clk && !IS_ERR(clk))
-                module_put(clk->owner);
-}
-EXPORT_SYMBOL(clk_put);
-
-static int __clk_enable(struct clk *clk)
-{
-        if (clk->flags & ALWAYS_ENABLED)
-                return 0;
-
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 1);
-        return 0;
+        if (clk->parent)
+                __clk_enable(clk->parent);
+        if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
+                davinci_psc_config(psc_domain(clk), clk->lpsc, 1);
 }
 
 static void __clk_disable(struct clk *clk)
 {
-        if (clk->usecount)
+        if (WARN_ON(clk->usecount == 0))
                 return;
-
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 0);
+        if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
+                davinci_psc_config(psc_domain(clk), clk->lpsc, 0);
+        if (clk->parent)
+                __clk_disable(clk->parent);
 }
 
 int clk_enable(struct clk *clk)
 {
         unsigned long flags;
-        int ret = 0;
 
         if (clk == NULL || IS_ERR(clk))
                 return -EINVAL;
 
-        if (clk->usecount++ == 0) {
-                spin_lock_irqsave(&clockfw_lock, flags);
-                ret = __clk_enable(clk);
-                spin_unlock_irqrestore(&clockfw_lock, flags);
-        }
+        spin_lock_irqsave(&clockfw_lock, flags);
+        __clk_enable(clk);
+        spin_unlock_irqrestore(&clockfw_lock, flags);
 
-        return ret;
+        return 0;
 }
 EXPORT_SYMBOL(clk_enable);
 
@@ -123,11 +77,9 @@ void clk_disable(struct clk *clk)
         if (clk == NULL || IS_ERR(clk))
                 return;
 
-        if (clk->usecount > 0 && !(--clk->usecount)) {
-                spin_lock_irqsave(&clockfw_lock, flags);
-                __clk_disable(clk);
-                spin_unlock_irqrestore(&clockfw_lock, flags);
-        }
+        spin_lock_irqsave(&clockfw_lock, flags);
+        __clk_disable(clk);
+        spin_unlock_irqrestore(&clockfw_lock, flags);
 }
 EXPORT_SYMBOL(clk_disable);
 
@@ -136,7 +88,7 @@ unsigned long clk_get_rate(struct clk *clk)
         if (clk == NULL || IS_ERR(clk))
                 return -EINVAL;
 
-        return *(clk->rate);
+        return clk->rate;
 }
 EXPORT_SYMBOL(clk_get_rate);
 
@@ -145,7 +97,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
         if (clk == NULL || IS_ERR(clk))
                 return -EINVAL;
 
-        return *(clk->rate);
+        return clk->rate;
 }
 EXPORT_SYMBOL(clk_round_rate);
 
@@ -164,10 +116,23 @@ int clk_register(struct clk *clk)
         if (clk == NULL || IS_ERR(clk))
                 return -EINVAL;
 
+        if (WARN(clk->parent && !clk->parent->rate,
+                        "CLK: %s parent %s has no rate!\n",
+                        clk->name, clk->parent->name))
+                return -EINVAL;
+
         mutex_lock(&clocks_mutex);
-        list_add(&clk->node, &clocks);
+        list_add_tail(&clk->node, &clocks);
         mutex_unlock(&clocks_mutex);
 
+        /* If rate is already set, use it */
+        if (clk->rate)
+                return 0;
+
+        /* Otherwise, default to parent rate */
+        if (clk->parent)
+                clk->rate = clk->parent->rate;
+
         return 0;
 }
 EXPORT_SYMBOL(clk_register);
@@ -183,84 +148,150 @@ void clk_unregister(struct clk *clk)
 }
 EXPORT_SYMBOL(clk_unregister);
 
-static struct clk davinci_clks[] = {
-        {
-                .name = "ARMCLK",
-                .rate = &armrate,
-                .lpsc = -1,
-                .flags = ALWAYS_ENABLED,
-        },
-        {
-                .name = "UART",
-                .rate = &fixedrate,
-                .lpsc = DAVINCI_LPSC_UART0,
-        },
-        {
-                .name = "EMACCLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_EMAC_WRAPPER,
-        },
-        {
-                .name = "I2CCLK",
-                .rate = &fixedrate,
-                .lpsc = DAVINCI_LPSC_I2C,
-        },
-        {
-                .name = "IDECLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_ATA,
-        },
-        {
-                .name = "McBSPCLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_McBSP,
-        },
-        {
-                .name = "MMCSDCLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_MMC_SD,
-        },
-        {
-                .name = "SPICLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_SPI,
-        },
-        {
-                .name = "gpio",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_GPIO,
-        },
-        {
-                .name = "usb",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_USB,
-        },
-        {
-                .name = "AEMIFCLK",
-                .rate = &commonrate,
-                .lpsc = DAVINCI_LPSC_AEMIF,
-                .usecount = 1,
+#ifdef CONFIG_DAVINCI_RESET_CLOCKS
+/*
+ * Disable any unused clocks left on by the bootloader
+ */
+static int __init clk_disable_unused(void)
+{
+        struct clk *ck;
+
+        spin_lock_irq(&clockfw_lock);
+        list_for_each_entry(ck, &clocks, node) {
+                if (ck->usecount > 0)
+                        continue;
+                if (!(ck->flags & CLK_PSC))
+                        continue;
+
+                /* ignore if in Disabled or SwRstDisable states */
+                if (!davinci_psc_is_clk_active(ck->lpsc))
+                        continue;
+
+                pr_info("Clocks: disable unused %s\n", ck->name);
+                davinci_psc_config(psc_domain(ck), ck->lpsc, 0);
         }
-};
+        spin_unlock_irq(&clockfw_lock);
+
+        return 0;
+}
+late_initcall(clk_disable_unused);
+#endif
 
-int __init davinci_clk_init(void)
+static void clk_sysclk_recalc(struct clk *clk)
 {
-        struct clk *clkp;
-        int count = 0;
-        u32 pll_mult;
-
-        pll_mult = davinci_readl(DAVINCI_PLL_CNTRL0_BASE + PLLM);
-        commonrate = ((pll_mult + 1) * 27000000) / 6;
-        armrate = ((pll_mult + 1) * 27000000) / 2;
-
-        for (clkp = davinci_clks; count < ARRAY_SIZE(davinci_clks);
-             count++, clkp++) {
-                clk_register(clkp);
-
-                /* Turn on clocks that have been enabled in the
-                 * table above */
-                if (clkp->usecount)
-                        clk_enable(clkp);
+        u32 v, plldiv;
+        struct pll_data *pll;
+
+        /* If this is the PLL base clock, no more calculations needed */
+        if (clk->pll_data)
+                return;
+
+        if (WARN_ON(!clk->parent))
+                return;
+
+        clk->rate = clk->parent->rate;
+
+        /* Otherwise, the parent must be a PLL */
+        if (WARN_ON(!clk->parent->pll_data))
+                return;
+
+        pll = clk->parent->pll_data;
+
+        /* If pre-PLL, source clock is before the multiplier and divider(s) */
+        if (clk->flags & PRE_PLL)
+                clk->rate = pll->input_rate;
+
+        if (!clk->div_reg)
+                return;
+
+        v = __raw_readl(pll->base + clk->div_reg);
+        if (v & PLLDIV_EN) {
+                plldiv = (v & PLLDIV_RATIO_MASK) + 1;
+                if (plldiv)
+                        clk->rate /= plldiv;
+        }
+}
+
+static void __init clk_pll_init(struct clk *clk)
+{
+        u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
+        u8 bypass;
+        struct pll_data *pll = clk->pll_data;
+
+        pll->base = IO_ADDRESS(pll->phys_base);
+        ctrl = __raw_readl(pll->base + PLLCTL);
+        clk->rate = pll->input_rate = clk->parent->rate;
+
+        if (ctrl & PLLCTL_PLLEN) {
+                bypass = 0;
+                mult = __raw_readl(pll->base + PLLM);
+                mult = (mult & PLLM_PLLM_MASK) + 1;
+        } else
+                bypass = 1;
+
+        if (pll->flags & PLL_HAS_PREDIV) {
+                prediv = __raw_readl(pll->base + PREDIV);
+                if (prediv & PLLDIV_EN)
+                        prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
+                else
+                        prediv = 1;
+        }
+
+        /* pre-divider is fixed, but (some?) chips won't report that */
+        if (cpu_is_davinci_dm355() && pll->num == 1)
+                prediv = 8;
+
+        if (pll->flags & PLL_HAS_POSTDIV) {
+                postdiv = __raw_readl(pll->base + POSTDIV);
+                if (postdiv & PLLDIV_EN)
+                        postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
+                else
+                        postdiv = 1;
+        }
+
+        if (!bypass) {
+                clk->rate /= prediv;
+                clk->rate *= mult;
+                clk->rate /= postdiv;
+        }
+
+        pr_debug("PLL%d: input = %lu MHz [ ",
+                 pll->num, clk->parent->rate / 1000000);
+        if (bypass)
+                pr_debug("bypass ");
+        if (prediv > 1)
+                pr_debug("/ %d ", prediv);
+        if (mult > 1)
+                pr_debug("* %d ", mult);
+        if (postdiv > 1)
+                pr_debug("/ %d ", postdiv);
+        pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000);
+}
+
+int __init davinci_clk_init(struct davinci_clk *clocks)
+  {
+        struct davinci_clk *c;
+        struct clk *clk;
+
+        for (c = clocks; c->lk.clk; c++) {
+                clk = c->lk.clk;
+
+                if (clk->pll_data)
+                        clk_pll_init(clk);
+
+                /* Calculate rates for PLL-derived clocks */
+                else if (clk->flags & CLK_PLL)
+                        clk_sysclk_recalc(clk);
+
+                if (clk->lpsc)
+                        clk->flags |= CLK_PSC;
+
+                clkdev_add(&c->lk);
+                clk_register(clk);
+
+                /* Turn on clocks that Linux doesn't otherwise manage */
+                if (clk->flags & ALWAYS_ENABLED)
+                        clk_enable(clk);
         }
 
         return 0;
@@ -285,12 +316,52 @@ static void davinci_ck_stop(struct seq_file *m, void *v)
 {
 }
 
-static int davinci_ck_show(struct seq_file *m, void *v)
+#define CLKNAME_MAX     10              /* longest clock name */
+#define NEST_DELTA      2
+#define NEST_MAX        4
+
+static void
+dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
 {
-        struct clk *cp;
+        char            *state;
+        char            buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
+        struct clk      *clk;
+        unsigned        i;
+
+        if (parent->flags & CLK_PLL)
+                state = "pll";
+        else if (parent->flags & CLK_PSC)
+                state = "psc";
+        else
+                state = "";
+
+        /* <nest spaces> name <pad to end> */
+        memset(buf, ' ', sizeof(buf) - 1);
+        buf[sizeof(buf) - 1] = 0;
+        i = strlen(parent->name);
+        memcpy(buf + nest, parent->name,
+                        min(i, (unsigned)(sizeof(buf) - 1 - nest)));
+
+        seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
+                   buf, parent->usecount, state, clk_get_rate(parent));
+        /* REVISIT show device associations too */
+
+        /* cost is now small, but not linear... */
+        list_for_each_entry(clk, &clocks, node) {
+                if (clk->parent == parent)
+                        dump_clock(s, nest + NEST_DELTA, clk);
+        }
+}
 
-        list_for_each_entry(cp, &clocks, node)
-                seq_printf(m,"%s %d %d\n", cp->name, *(cp->rate), cp->usecount);
+static int davinci_ck_show(struct seq_file *m, void *v)
+{
+        /* Show clock tree; we know the main oscillator is first.
+         * We trust nonzero usecounts equate to PSC enables...
+         */
+        mutex_lock(&clocks_mutex);
+        if (!list_empty(&clocks))
+                dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
+        mutex_unlock(&clocks_mutex);
 
         return 0;
 }
@@ -321,4 +392,4 @@ static int __init davinci_ck_proc_init(void)
 
 }
 __initcall(davinci_ck_proc_init);
-#endif  /* CONFIG_DEBUG_PROC_FS */
+#endif /* CONFIG_DEBUG_PROC_FS */
diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h
index ed47079a52e4..35736ec202f8 100644
--- a/arch/arm/mach-davinci/clock.h
+++ b/arch/arm/mach-davinci/clock.h
@@ -1,7 +1,8 @@
 /*
  * TI DaVinci clock definitions
  *
- * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2006-2007 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -11,23 +12,85 @@
 #ifndef __ARCH_ARM_DAVINCI_CLOCK_H
 #define __ARCH_ARM_DAVINCI_CLOCK_H
 
+#include <linux/list.h>
+#include <asm/clkdev.h>
+
+#define DAVINCI_PLL1_BASE 0x01c40800
+#define DAVINCI_PLL2_BASE 0x01c40c00
+#define MAX_PLL 2
+
+/* PLL/Reset register offsets */
+#define PLLCTL          0x100
+#define PLLCTL_PLLEN    BIT(0)
+#define PLLCTL_CLKMODE  BIT(8)
+
+#define PLLM            0x110
+#define PLLM_PLLM_MASK  0xff
+
+#define PREDIV          0x114
+#define PLLDIV1         0x118
+#define PLLDIV2         0x11c
+#define PLLDIV3         0x120
+#define POSTDIV         0x128
+#define BPDIV           0x12c
+#define PLLCMD          0x138
+#define PLLSTAT         0x13c
+#define PLLALNCTL       0x140
+#define PLLDCHANGE      0x144
+#define PLLCKEN         0x148
+#define PLLCKSTAT       0x14c
+#define PLLSYSTAT       0x150
+#define PLLDIV4         0x160
+#define PLLDIV5         0x164
+#define PLLDIV6         0x168
+#define PLLDIV7         0x16c
+#define PLLDIV8         0x170
+#define PLLDIV9         0x174
+#define PLLDIV_EN       BIT(15)
+#define PLLDIV_RATIO_MASK 0x1f
+
+struct pll_data {
+        u32 phys_base;
+        void __iomem *base;
+        u32 num;
+        u32 flags;
+        u32 input_rate;
+};
+#define PLL_HAS_PREDIV          0x01
+#define PLL_HAS_POSTDIV         0x02
+
 struct clk {
         struct list_head        node;
         struct module           *owner;
         const char              *name;
-        unsigned int            *rate;
-        int                     id;
-        __s8                    usecount;
-        __u8                    flags;
-        __u8                    lpsc;
+        unsigned long           rate;
+        u8                      usecount;
+        u8                      flags;
+        u8                      lpsc;
+        struct clk              *parent;
+        struct pll_data         *pll_data;
+        u32                     div_reg;
 };
 
 /* Clock flags */
-#define RATE_CKCTL              1
-#define RATE_FIXED              2
-#define RATE_PROPAGATES         4
-#define VIRTUAL_CLOCK           8
-#define ALWAYS_ENABLED          16
-#define ENABLE_REG_32BIT        32
+#define ALWAYS_ENABLED          BIT(1)
+#define CLK_PSC                 BIT(2)
+#define PSC_DSP                 BIT(3) /* PSC uses DSP domain, not ARM */
+#define CLK_PLL                 BIT(4) /* PLL-derived clock */
+#define PRE_PLL                 BIT(5) /* source is before PLL mult/div */
+
+struct davinci_clk {
+        struct clk_lookup lk;
+};
+
+#define CLK(dev, con, ck)               \
+        {                               \
+                .lk = {                 \
+                        .dev_id = dev,  \
+                        .con_id = con,  \
+                        .clk = ck,      \
+                },                      \
+        }
 
+int davinci_clk_init(struct davinci_clk *clocks);
 #endif
diff --git a/arch/arm/mach-davinci/include/mach/clkdev.h b/arch/arm/mach-davinci/include/mach/clkdev.h
new file mode 100644
index 000000000000..730c49d1ebd8
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/clkdev.h
@@ -0,0 +1,13 @@
+#ifndef __MACH_CLKDEV_H
+#define __MACH_CLKDEV_H
+
+static inline int __clk_get(struct clk *clk)
+{
+        return 1;
+}
+
+static inline void __clk_put(struct clk *clk)
+{
+}
+
+#endif
diff --git a/arch/arm/mach-davinci/include/mach/clock.h b/arch/arm/mach-davinci/include/mach/clock.h
index 38bdd49bc181..a3b040219876 100644
--- a/arch/arm/mach-davinci/include/mach/clock.h
+++ b/arch/arm/mach-davinci/include/mach/clock.h
@@ -17,6 +17,5 @@ struct clk;
 
 extern int clk_register(struct clk *clk);
 extern void clk_unregister(struct clk *clk);
-extern int davinci_clk_init(void);
 
 #endif
diff --git a/arch/arm/mach-davinci/include/mach/psc.h b/arch/arm/mach-davinci/include/mach/psc.h
index 4977aa071e1e..55a90d419fac 100644
--- a/arch/arm/mach-davinci/include/mach/psc.h
+++ b/arch/arm/mach-davinci/include/mach/psc.h
@@ -38,8 +38,6 @@
 #define DAVINCI_LPSC_TPTC1          4
 #define DAVINCI_LPSC_EMAC           5
 #define DAVINCI_LPSC_EMAC_WRAPPER   6
-#define DAVINCI_LPSC_MDIO           7
-#define DAVINCI_LPSC_IEEE1394       8
 #define DAVINCI_LPSC_USB            9
 #define DAVINCI_LPSC_ATA            10
 #define DAVINCI_LPSC_VLYNQ          11
@@ -47,7 +45,6 @@
 #define DAVINCI_LPSC_DDR_EMIF       13
 #define DAVINCI_LPSC_AEMIF          14
 #define DAVINCI_LPSC_MMC_SD         15
-#define DAVINCI_LPSC_MEMSTICK       16
 #define DAVINCI_LPSC_McBSP          17
 #define DAVINCI_LPSC_I2C            18
 #define DAVINCI_LPSC_UART0          19
@@ -73,4 +70,54 @@
 #define DAVINCI_LPSC_GEM            39
 #define DAVINCI_LPSC_IMCOP          40
 
+#define DM355_LPSC_TIMER3               5
+#define DM355_LPSC_SPI1                 6
+#define DM355_LPSC_MMC_SD1              7
+#define DM355_LPSC_McBSP1               8
+#define DM355_LPSC_PWM3                 10
+#define DM355_LPSC_SPI2                 11
+#define DM355_LPSC_RTO                  12
+#define DM355_LPSC_VPSS_DAC             41
+
+/*
+ * LPSC Assignments
+ */
+#define DM646X_LPSC_ARM            0
+#define DM646X_LPSC_C64X_CPU       1
+#define DM646X_LPSC_HDVICP0        2
+#define DM646X_LPSC_HDVICP1        3
+#define DM646X_LPSC_TPCC           4
+#define DM646X_LPSC_TPTC0          5
+#define DM646X_LPSC_TPTC1          6
+#define DM646X_LPSC_TPTC2          7
+#define DM646X_LPSC_TPTC3          8
+#define DM646X_LPSC_PCI            13
+#define DM646X_LPSC_EMAC           14
+#define DM646X_LPSC_VDCE           15
+#define DM646X_LPSC_VPSSMSTR       16
+#define DM646X_LPSC_VPSSSLV        17
+#define DM646X_LPSC_TSIF0          18
+#define DM646X_LPSC_TSIF1          19
+#define DM646X_LPSC_DDR_EMIF       20
+#define DM646X_LPSC_AEMIF          21
+#define DM646X_LPSC_McASP0         22
+#define DM646X_LPSC_McASP1         23
+#define DM646X_LPSC_CRGEN0         24
+#define DM646X_LPSC_CRGEN1         25
+#define DM646X_LPSC_UART0          26
+#define DM646X_LPSC_UART1          27
+#define DM646X_LPSC_UART2          28
+#define DM646X_LPSC_PWM0           29
+#define DM646X_LPSC_PWM1           30
+#define DM646X_LPSC_I2C            31
+#define DM646X_LPSC_SPI            32
+#define DM646X_LPSC_GPIO           33
+#define DM646X_LPSC_TIMER0         34
+#define DM646X_LPSC_TIMER1         35
+#define DM646X_LPSC_ARM_INTC       45
+
+extern int davinci_psc_is_clk_active(unsigned int id);
+extern void davinci_psc_config(unsigned int domain, unsigned int id,
+                               char enable);
+
 #endif /* __ASM_ARCH_PSC_H */
diff --git a/arch/arm/mach-davinci/io.c b/arch/arm/mach-davinci/io.c
index 299515f70b8b..71a7ae342b91 100644
--- a/arch/arm/mach-davinci/io.c
+++ b/arch/arm/mach-davinci/io.c
@@ -53,5 +53,4 @@ void __init davinci_map_common_io(void)
 
 void __init davinci_init_common_hw(void)
 {
-        davinci_clk_init();
 }
diff --git a/arch/arm/mach-davinci/psc.c b/arch/arm/mach-davinci/psc.c
index 58754f066d5b..c5098831741f 100644
--- a/arch/arm/mach-davinci/psc.c
+++ b/arch/arm/mach-davinci/psc.c
@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 
+#include <mach/cputype.h>
 #include <mach/hardware.h>
 #include <mach/psc.h>
 #include <mach/mux.h>
@@ -36,76 +37,57 @@
 #define MDSTAT          0x800
 #define MDCTL           0xA00
 
-/* System control register offsets */
-#define VDD3P3V_PWDN    0x48
 
-static void davinci_psc_mux(unsigned int id)
+/* Return nonzero iff the domain's clock is active */
+int __init davinci_psc_is_clk_active(unsigned int id)
 {
-        switch (id) {
-        case DAVINCI_LPSC_ATA:
-                davinci_mux_peripheral(DAVINCI_MUX_HDIREN, 1);
-                davinci_mux_peripheral(DAVINCI_MUX_ATAEN, 1);
-                break;
-        case DAVINCI_LPSC_MMC_SD:
-                /* VDD power manupulations are done in U-Boot for CPMAC
-                 * so applies to MMC as well
-                 */
-                /*Set up the pull regiter for MMC */
-                davinci_writel(0, DAVINCI_SYSTEM_MODULE_BASE + VDD3P3V_PWDN);
-                davinci_mux_peripheral(DAVINCI_MUX_MSTK, 0);
-                break;
-        case DAVINCI_LPSC_I2C:
-                davinci_mux_peripheral(DAVINCI_MUX_I2C, 1);
-                break;
-        case DAVINCI_LPSC_McBSP:
-                davinci_mux_peripheral(DAVINCI_MUX_ASP, 1);
-                break;
-        default:
-                break;
-        }
+        void __iomem *psc_base = IO_ADDRESS(DAVINCI_PWR_SLEEP_CNTRL_BASE);
+        u32 mdstat = __raw_readl(psc_base + MDSTAT + 4 * id);
+
+        /* if clocked, state can be "Enable" or "SyncReset" */
+        return mdstat & BIT(12);
 }
 
 /* Enable or disable a PSC domain */
 void davinci_psc_config(unsigned int domain, unsigned int id, char enable)
 {
         u32 epcpr, ptcmd, ptstat, pdstat, pdctl1, mdstat, mdctl, mdstat_mask;
+        void __iomem *psc_base = IO_ADDRESS(DAVINCI_PWR_SLEEP_CNTRL_BASE);
 
-        mdctl = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE + MDCTL + 4 * id);
+        mdctl = __raw_readl(psc_base + MDCTL + 4 * id);
         if (enable)
                 mdctl |= 0x00000003;    /* Enable Module */
         else
-                mdctl &= 0xFFFFFFF2;    /* Disable Module */
-        davinci_writel(mdctl, DAVINCI_PWR_SLEEP_CNTRL_BASE + MDCTL + 4 * id);
+                mdctl &= 0xFFFFFFE2;    /* Disable Module */
+        __raw_writel(mdctl, psc_base + MDCTL + 4 * id);
 
-        pdstat = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE + PDSTAT);
+        pdstat = __raw_readl(psc_base + PDSTAT);
         if ((pdstat & 0x00000001) == 0) {
-                pdctl1 = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE + PDCTL1);
+                pdctl1 = __raw_readl(psc_base + PDCTL1);
                 pdctl1 |= 0x1;
-                davinci_writel(pdctl1, DAVINCI_PWR_SLEEP_CNTRL_BASE + PDCTL1);
+                __raw_writel(pdctl1, psc_base + PDCTL1);
 
                 ptcmd = 1 << domain;
-                davinci_writel(ptcmd, DAVINCI_PWR_SLEEP_CNTRL_BASE + PTCMD);
+                __raw_writel(ptcmd, psc_base + PTCMD);
 
                 do {
-                        epcpr = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE +
-                                              EPCPR);
+                        epcpr = __raw_readl(psc_base + EPCPR);
                 } while ((((epcpr >> domain) & 1) == 0));
 
-                pdctl1 = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE + PDCTL1);
+                pdctl1 = __raw_readl(psc_base + PDCTL1);
                 pdctl1 |= 0x100;
-                davinci_writel(pdctl1, DAVINCI_PWR_SLEEP_CNTRL_BASE + PDCTL1);
+                __raw_writel(pdctl1, psc_base + PDCTL1);
 
                 do {
-                        ptstat = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE +
+                        ptstat = __raw_readl(psc_base +
                                                PTSTAT);
                 } while (!(((ptstat >> domain) & 1) == 0));
         } else {
                 ptcmd = 1 << domain;
-                davinci_writel(ptcmd, DAVINCI_PWR_SLEEP_CNTRL_BASE + PTCMD);
+                __raw_writel(ptcmd, psc_base + PTCMD);
 
                 do {
-                        ptstat = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE +
-                                               PTSTAT);
+                        ptstat = __raw_readl(psc_base + PTSTAT);
                 } while (!(((ptstat >> domain) & 1) == 0));
         }
 
@@ -115,23 +97,6 @@ void davinci_psc_config(unsigned int domain, unsigned int id, char enable)
                 mdstat_mask = 0x2;
 
         do {
-                mdstat = davinci_readl(DAVINCI_PWR_SLEEP_CNTRL_BASE +
-                                       MDSTAT + 4 * id);
+                mdstat = __raw_readl(psc_base + MDSTAT + 4 * id);
         } while (!((mdstat & 0x0000001F) == mdstat_mask));
-
-        if (enable)
-                davinci_psc_mux(id);
-}
-
-void __init davinci_psc_init(void)
-{
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_VPSSMSTR, 1);
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_VPSSSLV, 1);
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_TPCC, 1);
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_TPTC0, 1);
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_TPTC1, 1);
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_GPIO, 1);
-
-        /* Turn on WatchDog timer LPSC.  Needed for RESET to work */
-        davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, DAVINCI_LPSC_TIMER2, 1);
 }