OMAP2xxx clock: move the DPLL+CORE composite clock code into mach-omap2/clkt2xxx_dpllcore.c

Move the DPLL+CORE composite clock functions from clock2xxx.c to
mach-omap2/clkt2xxx_dpllcore.c.  This is intended to make the clock
code easier to understand, since all of the functions needed to manage
the OMAP2 DPLL+CORE clock are now located in their own file, rather
than being mixed with other, unrelated functions.

Clock debugging is also now more finely-grained, since the DEBUG
macro can now be defined for the DPLL+CORE clock alone.  This
should reduce unnecessary console noise when debugging.

Also, if at some future point the mach-omap2/ directory is split
into OMAP2/3/4 variants, this clkt file can be placed in the mach-omap2xxx/
directory, rather than shared with other chip types that don't use this
clock type.

Thanks to Alexander Shishkin <virtuoso@slind.org> for his comments to
improve the patch description.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Alexander Shishkin <virtuoso@slind.org>

3 files changed, 176 insertions, 137 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 9ecc58d2c986..04ce372bb105 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -11,8 +11,10 @@ prcm-common				= prcm.o powerdomain.o
 clock-common                            = clock.o clock_common_data.o \
                                           clockdomain.o clkt_dpll.o \
                                           clkt_clksel.o
+clock-omap2xxx                          = clkt2xxx_dpllcore.o
 
-obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(clock-common)
+obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(clock-common) \
+                            $(clock-omap2xxx)
 obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common) $(clock-common) \
                             $(omap-3-4-common)
 obj-$(CONFIG_ARCH_OMAP4) += $(omap-3-4-common) $(prcm-common) $(clock-common)
diff --git a/arch/arm/mach-omap2/clkt2xxx_dpllcore.c b/arch/arm/mach-omap2/clkt2xxx_dpllcore.c
new file mode 100644
index 000000000000..019048434f13
--- /dev/null
+++ b/arch/arm/mach-omap2/clkt2xxx_dpllcore.c
@@ -0,0 +1,173 @@
+/*
+ * DPLL + CORE_CLK composite clock functions
+ *
+ * Copyright (C) 2005-2008 Texas Instruments, Inc.
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Contacts:
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Paul Walmsley
+ *
+ * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
+ * Gordon McNutt and RidgeRun, Inc.
+ *
+ * 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
+ * published by the Free Software Foundation.
+ *
+ * XXX The DPLL and CORE clocks should be split into two separate clock
+ * types.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/clock.h>
+#include <plat/sram.h>
+#include <plat/sdrc.h>
+
+#include "clock.h"
+#include "clock2xxx.h"
+#include "opp2xxx.h"
+#include "cm.h"
+#include "cm-regbits-24xx.h"
+
+/* #define DOWN_VARIABLE_DPLL 1 */              /* Experimental */
+
+/**
+ * omap2xxx_clk_get_core_rate - return the CORE_CLK rate
+ * @clk: pointer to the combined dpll_ck + core_ck (currently "dpll_ck")
+ *
+ * Returns the CORE_CLK rate.  CORE_CLK can have one of three rate
+ * sources on OMAP2xxx: the DPLL CLKOUT rate, DPLL CLKOUTX2, or 32KHz
+ * (the latter is unusual).  This currently should be called with
+ * struct clk *dpll_ck, which is a composite clock of dpll_ck and
+ * core_ck.
+ */
+unsigned long omap2xxx_clk_get_core_rate(struct clk *clk)
+{
+        long long core_clk;
+        u32 v;
+
+        core_clk = omap2_get_dpll_rate(clk);
+
+        v = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
+        v &= OMAP24XX_CORE_CLK_SRC_MASK;
+
+        if (v == CORE_CLK_SRC_32K)
+                core_clk = 32768;
+        else
+                core_clk *= v;
+
+        return core_clk;
+}
+
+/*
+ * Uses the current prcm set to tell if a rate is valid.
+ * You can go slower, but not faster within a given rate set.
+ */
+static long omap2_dpllcore_round_rate(unsigned long target_rate)
+{
+        u32 high, low, core_clk_src;
+
+        core_clk_src = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
+        core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK;
+
+        if (core_clk_src == CORE_CLK_SRC_DPLL) {        /* DPLL clockout */
+                high = curr_prcm_set->dpll_speed * 2;
+                low = curr_prcm_set->dpll_speed;
+        } else {                                /* DPLL clockout x 2 */
+                high = curr_prcm_set->dpll_speed;
+                low = curr_prcm_set->dpll_speed / 2;
+        }
+
+#ifdef DOWN_VARIABLE_DPLL
+        if (target_rate > high)
+                return high;
+        else
+                return target_rate;
+#else
+        if (target_rate > low)
+                return high;
+        else
+                return low;
+#endif
+
+}
+
+unsigned long omap2_dpllcore_recalc(struct clk *clk)
+{
+        return omap2xxx_clk_get_core_rate(clk);
+}
+
+int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate)
+{
+        u32 cur_rate, low, mult, div, valid_rate, done_rate;
+        u32 bypass = 0;
+        struct prcm_config tmpset;
+        const struct dpll_data *dd;
+
+        cur_rate = omap2xxx_clk_get_core_rate(dclk);
+        mult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
+        mult &= OMAP24XX_CORE_CLK_SRC_MASK;
+
+        if ((rate == (cur_rate / 2)) && (mult == 2)) {
+                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
+        } else if ((rate == (cur_rate * 2)) && (mult == 1)) {
+                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
+        } else if (rate != cur_rate) {
+                valid_rate = omap2_dpllcore_round_rate(rate);
+                if (valid_rate != rate)
+                        return -EINVAL;
+
+                if (mult == 1)
+                        low = curr_prcm_set->dpll_speed;
+                else
+                        low = curr_prcm_set->dpll_speed / 2;
+
+                dd = clk->dpll_data;
+                if (!dd)
+                        return -EINVAL;
+
+                tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg);
+                tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
+                                           dd->div1_mask);
+                div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
+                tmpset.cm_clksel2_pll = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
+                tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
+                if (rate > low) {
+                        tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
+                        mult = ((rate / 2) / 1000000);
+                        done_rate = CORE_CLK_SRC_DPLL_X2;
+                } else {
+                        tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
+                        mult = (rate / 1000000);
+                        done_rate = CORE_CLK_SRC_DPLL;
+                }
+                tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
+                tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
+
+                /* Worst case */
+                tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
+
+                if (rate == curr_prcm_set->xtal_speed)  /* If asking for 1-1 */
+                        bypass = 1;
+
+                /* For omap2xxx_sdrc_init_params() */
+                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
+
+                /* Force dll lock mode */
+                omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
+                               bypass);
+
+                /* Errata: ret dll entry state */
+                omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
+                omap2xxx_sdrc_reprogram(done_rate, 0);
+        }
+
+        return 0;
+}
+
diff --git a/arch/arm/mach-omap2/clock2xxx.c b/arch/arm/mach-omap2/clock2xxx.c
index bef557488fec..419ae80fa1d4 100644
--- a/arch/arm/mach-omap2/clock2xxx.c
+++ b/arch/arm/mach-omap2/clock2xxx.c
@@ -54,8 +54,6 @@
 #define APLLS_CLKIN_13MHZ               2
 #define APLLS_CLKIN_12MHZ               3
 
-/* #define DOWN_VARIABLE_DPLL 1 */              /* Experimental */
-
 const struct prcm_config *curr_prcm_set;
 const struct prcm_config *rate_table;
 
@@ -94,34 +92,6 @@ const struct clkops clkops_omap2430_i2chs_wait = {
         .find_companion = omap2_clk_dflt_find_companion,
 };
 
-/**
- * omap2xxx_clk_get_core_rate - return the CORE_CLK rate
- * @clk: pointer to the combined dpll_ck + core_ck (currently "dpll_ck")
- *
- * Returns the CORE_CLK rate.  CORE_CLK can have one of three rate
- * sources on OMAP2xxx: the DPLL CLKOUT rate, DPLL CLKOUTX2, or 32KHz
- * (the latter is unusual).  This currently should be called with
- * struct clk *dpll_ck, which is a composite clock of dpll_ck and
- * core_ck.
- */
-unsigned long omap2xxx_clk_get_core_rate(struct clk *clk)
-{
-        long long core_clk;
-        u32 v;
-
-        core_clk = omap2_get_dpll_rate(clk);
-
-        v = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
-        v &= OMAP24XX_CORE_CLK_SRC_MASK;
-
-        if (v == CORE_CLK_SRC_32K)
-                core_clk = 32768;
-        else
-                core_clk *= v;
-
-        return core_clk;
-}
-
 static int omap2_enable_osc_ck(struct clk *clk)
 {
         u32 pcc;
@@ -215,112 +185,6 @@ const struct clkops clkops_apll54 = {
         .disable        = omap2_clk_apll_disable,
 };
 
-/*
- * Uses the current prcm set to tell if a rate is valid.
- * You can go slower, but not faster within a given rate set.
- */
-long omap2_dpllcore_round_rate(unsigned long target_rate)
-{
-        u32 high, low, core_clk_src;
-
-        core_clk_src = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
-        core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK;
-
-        if (core_clk_src == CORE_CLK_SRC_DPLL) {        /* DPLL clockout */
-                high = curr_prcm_set->dpll_speed * 2;
-                low = curr_prcm_set->dpll_speed;
-        } else {                                /* DPLL clockout x 2 */
-                high = curr_prcm_set->dpll_speed;
-                low = curr_prcm_set->dpll_speed / 2;
-        }
-
-#ifdef DOWN_VARIABLE_DPLL
-        if (target_rate > high)
-                return high;
-        else
-                return target_rate;
-#else
-        if (target_rate > low)
-                return high;
-        else
-                return low;
-#endif
-
-}
-
-unsigned long omap2_dpllcore_recalc(struct clk *clk)
-{
-        return omap2xxx_clk_get_core_rate(clk);
-}
-
-int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate)
-{
-        u32 cur_rate, low, mult, div, valid_rate, done_rate;
-        u32 bypass = 0;
-        struct prcm_config tmpset;
-        const struct dpll_data *dd;
-
-        cur_rate = omap2xxx_clk_get_core_rate(dclk);
-        mult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
-        mult &= OMAP24XX_CORE_CLK_SRC_MASK;
-
-        if ((rate == (cur_rate / 2)) && (mult == 2)) {
-                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
-        } else if ((rate == (cur_rate * 2)) && (mult == 1)) {
-                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
-        } else if (rate != cur_rate) {
-                valid_rate = omap2_dpllcore_round_rate(rate);
-                if (valid_rate != rate)
-                        return -EINVAL;
-
-                if (mult == 1)
-                        low = curr_prcm_set->dpll_speed;
-                else
-                        low = curr_prcm_set->dpll_speed / 2;
-
-                dd = clk->dpll_data;
-                if (!dd)
-                        return -EINVAL;
-
-                tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg);
-                tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
-                                           dd->div1_mask);
-                div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
-                tmpset.cm_clksel2_pll = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
-                tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
-                if (rate > low) {
-                        tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
-                        mult = ((rate / 2) / 1000000);
-                        done_rate = CORE_CLK_SRC_DPLL_X2;
-                } else {
-                        tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
-                        mult = (rate / 1000000);
-                        done_rate = CORE_CLK_SRC_DPLL;
-                }
-                tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
-                tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
-
-                /* Worst case */
-                tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
-
-                if (rate == curr_prcm_set->xtal_speed)  /* If asking for 1-1 */
-                        bypass = 1;
-
-                /* For omap2xxx_sdrc_init_params() */
-                omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
-
-                /* Force dll lock mode */
-                omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
-                               bypass);
-
-                /* Errata: ret dll entry state */
-                omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
-                omap2xxx_sdrc_reprogram(done_rate, 0);
-        }
-
-        return 0;
-}
-
 /**
  * omap2_table_mpu_recalc - just return the MPU speed
  * @clk: virt_prcm_set struct clk