OMAP2/3/4 clock: fix DPLL multiplier value errors; also copyrights, includes, documentation

The maximum DPLL multiplier (M) values for OMAP2xxx and OMAP3xxx are
one increment higher than they should be.  See for example the
OMAP242x TRM Rev X Section 5.10.6 "Clock Generator Registers" and the
OMAP36xx TRM Rev C Table 3-202 "CM_CLKSEL1_PLL".  Programming a 0 into
the DPLL's M register bitfield is valid for OMAP2/3 and indicates that
the DPLL should enter MN-bypass mode.  Also, increase the minimum
multiplier (M) value for the DPLL rate rounding code from 1 to 2, to
ensure that it does not inadvertently put the DPLL into bypass.

Note that the register documentation in the OMAP2xxx and OMAP3xxx TRMs
does not make clear that the actual DPLL divider value (the "N") is
the content of the appropriate register bitfield for the N value,
_plus one_.  (In other words, an N register bitfield of 0 indicates a
DPLL divider value of 1.)  This is only clearly documented in the
OMAP4430 TRM, in, for example, OMAP4430 TRM Rev A Table 3-1167
"CM_CLKSEL_DPLL_USB".

While here, update copyrights, add kerneldoc for struct dpll_data,
drop the unused struct dpll_data.max_tolerance field, remove some
unnecessary #includes in DPLL-related code, and replace the #include
of <linux/module.h> with <linux/list.h>, which is what was really
needed.  The OMAP4 clock autogenerator script has been updated
accordingly.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>

1 files changed, 52 insertions, 12 deletions

diff --git a/arch/arm/plat-omap/include/plat/clock.h b/arch/arm/plat-omap/include/plat/clock.h
index 63a233490d6d..52f097b1e4d6 100644
--- a/arch/arm/plat-omap/include/plat/clock.h
+++ b/arch/arm/plat-omap/include/plat/clock.h
@@ -1,9 +1,9 @@
 /*
- *  arch/arm/plat-omap/include/mach/clock.h
+ * OMAP clock: data structure definitions, function prototypes, shared macros
  *
- *  Copyright (C) 2004 - 2005 Nokia corporation
- *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
- *  Based on clocks.h by Tony Lindgren, Gordon McNutt and RidgeRun, Inc
+ * Copyright (C) 2004-2005, 2008-2010 Nokia Corporation
+ * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ * Based on clocks.h by 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
@@ -41,9 +41,49 @@ struct clksel {
         const struct clksel_rate *rates;
 };
 
-/*
- * A new flag called flag has been added which indicates what is the
- * type of dpll (like j_type, no_dco_sel)
+/**
+ * struct dpll_data - DPLL registers and integration data
+ * @mult_div1_reg: register containing the DPLL M and N bitfields
+ * @mult_mask: mask of the DPLL M bitfield in @mult_div1_reg
+ * @div1_mask: mask of the DPLL N bitfield in @mult_div1_reg
+ * @clk_bypass: struct clk pointer to the clock's bypass clock input
+ * @clk_ref: struct clk pointer to the clock's reference clock input
+ * @control_reg: register containing the DPLL mode bitfield
+ * @enable_mask: mask of the DPLL mode bitfield in @control_reg
+ * @rate_tolerance: maximum variance allowed from target rate (in Hz)
+ * @last_rounded_rate: cache of the last rate result of omap2_dpll_round_rate()
+ * @last_rounded_m: cache of the last M result of omap2_dpll_round_rate()
+ * @max_multiplier: maximum valid non-bypass multiplier value (actual)
+ * @last_rounded_n: cache of the last N result of omap2_dpll_round_rate()
+ * @min_divider: minimum valid non-bypass divider value (actual)
+ * @max_divider: maximum valid non-bypass divider value (actual)
+ * @modes: possible values of @enable_mask
+ * @autoidle_reg: register containing the DPLL autoidle mode bitfield
+ * @idlest_reg: register containing the DPLL idle status bitfield
+ * @autoidle_mask: mask of the DPLL autoidle mode bitfield in @autoidle_reg
+ * @freqsel_mask: mask of the DPLL jitter correction bitfield in @control_reg
+ * @idlest_mask: mask of the DPLL idle status bitfield in @idlest_reg
+ * @auto_recal_bit: bitshift of the driftguard enable bit in @control_reg
+ * @recal_en_bit: bitshift of the PRM_IRQENABLE_* bit for recalibration IRQs
+ * @recal_st_bit: bitshift of the PRM_IRQSTATUS_* bit for recalibration IRQs
+ * @flags: DPLL type/features (see below)
+ *
+ * Possible values for @flags:
+ * DPLL_J_TYPE: "J-type DPLL" (only some 36xx, 4xxx DPLLs)
+ * NO_DCO_SEL: don't program DCO (only for some J-type DPLLs)
+
+ * @freqsel_mask is only used on the OMAP34xx family and AM35xx.
+ *
+ * XXX Some DPLLs have multiple bypass inputs, so it's not technically
+ * correct to only have one @clk_bypass pointer.
+ *
+ * XXX @rate_tolerance should probably be deprecated - currently there
+ * don't seem to be any usecases for DPLL rounding that is not exact.
+ *
+ * XXX The runtime-variable fields (@last_rounded_rate, @last_rounded_m,
+ * @last_rounded_n) should be separated from the runtime-fixed fields
+ * and placed into a differenct structure, so that the runtime-fixed data
+ * can be placed into read-only space.
  */
 struct dpll_data {
         void __iomem            *mult_div1_reg;
@@ -56,13 +96,12 @@ struct dpll_data {
         unsigned int            rate_tolerance;
         unsigned long           last_rounded_rate;
         u16                     last_rounded_m;
+        u16                     max_multiplier;
         u8                      last_rounded_n;
         u8                      min_divider;
         u8                      max_divider;
-        u32                     max_tolerance;
-        u16                     max_multiplier;
-#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
         u8                      modes;
+#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
         void __iomem            *autoidle_reg;
         void __iomem            *idlest_reg;
         u32                     autoidle_mask;
@@ -152,6 +191,7 @@ extern const struct clkops clkops_null;
 #define RATE_FIXED              (1 << 1)        /* Fixed clock rate */
 /* bits 2-4 are free */
 #define ENABLE_REG_32BIT        (1 << 5)        /* Use 32-bit access */
+/* bit 6 is free */
 #define CLOCK_IDLE_CONTROL      (1 << 7)
 #define CLOCK_NO_IDLE_PARENT    (1 << 8)
 #define DELAYED_APP             (1 << 9)        /* Delay application of clock */
@@ -160,14 +200,14 @@ extern const struct clkops clkops_null;
 #define INVERT_ENABLE           (1 << 12)       /* 0 enables, 1 disables */
 #define CLOCK_IN_OMAP4430       (1 << 13)
 #define ALWAYS_ENABLED          (1 << 14)
-/* bits 13-31 are currently free */
+/* bits 15-31 are currently free */
 
 /* Clksel_rate flags */
 #define DEFAULT_RATE            (1 << 0)
 #define RATE_IN_242X            (1 << 1)
 #define RATE_IN_243X            (1 << 2)
 #define RATE_IN_343X            (1 << 3)        /* rates common to all 343X */
-#define RATE_IN_3430ES2 (1 << 4)        /* 3430ES2 rates only */
+#define RATE_IN_3430ES2         (1 << 4)        /* 3430ES2 rates only */
 #define RATE_IN_36XX            (1 << 5)
 #define RATE_IN_4430            (1 << 6)