[PATCH v2 2/6] OMAP4: Clock: round_rate and recalc functions for DPLL_ABE
Paul Walmsley
paul at pwsan.com
Wed Sep 28 02:59:34 EDT 2011
Hi Jon and Mike,
On Fri, 16 Sep 2011, Jon Hunter wrote:
> From: Mike Turquette <mturquette at ti.com>
>
> OMAP4 DPLL_ABE can enable a 4X multipler on top of the normal MN multipler
> and divider. This is achieved by setting CM_CLKMODE_DPLL_ABE.DPLL_REGM4XEN
> bit in CKGEN module of CM1. From the OMAP4 TRM:
>
> Fdpll = Fref x 2 x (4 x M/(N+1)) in case REGM4XEN bit field is set (only
> applicable to DPLL_ABE).
>
> Add new round_rate() and recalc() functions for OMAP4, that check the
> setting of REGM4XEN bit and handle this appropriately. The new functions
> are a simple wrapper on top of the existing omap2_dpll_round_rate() and
> omap2_dpll_get_rate() functions to handle the REGM4XEN bit.
>
> The REGM4XEN bit is only implemented for the ABE DPLL on OMAP4 and so
> only dpll_abe_ck uses omap4_dpll_regm4xen_round_rate() and
> omap4_dpll_regm4xen_recalc() functions.
>
> Signed-off-by: Mike Turquette <mturquette at ti.com>
> Tested-by: Jon Hunter <jon-hunter at ti.com>
Some changes have been made to this patch here, to fix a few minor bugs in
error paths and to add documentation and Jon's Signed-off-by: (since he's
in the submittal chain).
Care to review and send any comments? Otherwise, I plan to queue this
revised version for 3.2.
Thanks for the great changelogs on this, and the other patches in this
series.
regards
- Paul
From: Mike Turquette <mturquette at ti.com>
Date: Wed, 28 Sep 2011 00:00:31 -0600
Subject: [PATCH] ARM: OMAP4: clock: round_rate and recalc functions for
DPLL_ABE
OMAP4 DPLL_ABE can enable a 4X multipler on top of the normal MN multipler
and divider. This is achieved by setting CM_CLKMODE_DPLL_ABE.DPLL_REGM4XEN
bit in CKGEN module of CM1. From the OMAP4 TRM:
Fdpll = Fref x 2 x (4 x M/(N+1)) in case REGM4XEN bit field is set (only
applicable to DPLL_ABE).
Add new round_rate() and recalc() functions for OMAP4, that check the
setting of REGM4XEN bit and handle this appropriately. The new functions
are a simple wrapper on top of the existing omap2_dpll_round_rate() and
omap2_dpll_get_rate() functions to handle the REGM4XEN bit.
The REGM4XEN bit is only implemented for the ABE DPLL on OMAP4 and so
only dpll_abe_ck uses omap4_dpll_regm4xen_round_rate() and
omap4_dpll_regm4xen_recalc() functions.
Signed-off-by: Mike Turquette <mturquette at ti.com>
Tested-by: Jon Hunter <jon-hunter at ti.com>
Signed-off-by: Jon Hunter <jon-hunter at ti.com>
[paul at pwsan.com: fixed attempt to return a negative from a fn returning
unsigned; pass along errors from omap2_dpll_round_rate();
added documentation; added Jon's S-o-b]
Signed-off-by: Paul Walmsley <paul at pwsan.com>
---
arch/arm/mach-omap2/clock.h | 2 +
arch/arm/mach-omap2/clock44xx.h | 7 +++
arch/arm/mach-omap2/clock44xx_data.c | 4 +-
arch/arm/mach-omap2/dpll44xx.c | 69 ++++++++++++++++++++++++++++++++++
4 files changed, 80 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-omap2/clock.h b/arch/arm/mach-omap2/clock.h
index 48ac568..2311bc2 100644
--- a/arch/arm/mach-omap2/clock.h
+++ b/arch/arm/mach-omap2/clock.h
@@ -66,6 +66,8 @@ void omap3_noncore_dpll_disable(struct clk *clk);
int omap4_dpllmx_gatectrl_read(struct clk *clk);
void omap4_dpllmx_allow_gatectrl(struct clk *clk);
void omap4_dpllmx_deny_gatectrl(struct clk *clk);
+long omap4_dpll_regm4xen_round_rate(struct clk *clk, unsigned long target_rate);
+unsigned long omap4_dpll_regm4xen_recalc(struct clk *clk);
#ifdef CONFIG_OMAP_RESET_CLOCKS
void omap2_clk_disable_unused(struct clk *clk);
diff --git a/arch/arm/mach-omap2/clock44xx.h b/arch/arm/mach-omap2/clock44xx.h
index 7ceb870..287a46f 100644
--- a/arch/arm/mach-omap2/clock44xx.h
+++ b/arch/arm/mach-omap2/clock44xx.h
@@ -8,6 +8,13 @@
#ifndef __ARCH_ARM_MACH_OMAP2_CLOCK44XX_H
#define __ARCH_ARM_MACH_OMAP2_CLOCK44XX_H
+/*
+ * OMAP4430_REGM4XEN_MULT: If the CM_CLKMODE_DPLL_ABE.DPLL_REGM4XEN bit is
+ * set, then the DPLL's lock frequency is multiplied by 4 (OMAP4430 TRM
+ * vV Section 3.6.3.3.1 "DPLLs Output Clocks Parameters")
+ */
+#define OMAP4430_REGM4XEN_MULT 4
+
int omap4xxx_clk_init(void);
#endif
diff --git a/arch/arm/mach-omap2/clock44xx_data.c b/arch/arm/mach-omap2/clock44xx_data.c
index c0b6fbd..c98c0a2 100644
--- a/arch/arm/mach-omap2/clock44xx_data.c
+++ b/arch/arm/mach-omap2/clock44xx_data.c
@@ -270,8 +270,8 @@ static struct clk dpll_abe_ck = {
.dpll_data = &dpll_abe_dd,
.init = &omap2_init_dpll_parent,
.ops = &clkops_omap3_noncore_dpll_ops,
- .recalc = &omap3_dpll_recalc,
- .round_rate = &omap2_dpll_round_rate,
+ .recalc = &omap4_dpll_regm4xen_recalc,
+ .round_rate = &omap4_dpll_regm4xen_round_rate,
.set_rate = &omap3_noncore_dpll_set_rate,
};
diff --git a/arch/arm/mach-omap2/dpll44xx.c b/arch/arm/mach-omap2/dpll44xx.c
index 4e4da61..9c6a296 100644
--- a/arch/arm/mach-omap2/dpll44xx.c
+++ b/arch/arm/mach-omap2/dpll44xx.c
@@ -19,6 +19,7 @@
#include <plat/clock.h>
#include "clock.h"
+#include "clock44xx.h"
#include "cm-regbits-44xx.h"
/* Supported only on OMAP4 */
@@ -82,3 +83,71 @@ const struct clkops clkops_omap4_dpllmx_ops = {
.deny_idle = omap4_dpllmx_deny_gatectrl,
};
+/**
+ * omap4_dpll_regm4xen_recalc - compute DPLL rate, considering REGM4XEN bit
+ * @clk: struct clk * of the DPLL to compute the rate for
+ *
+ * Compute the output rate for the OMAP4 DPLL represented by @clk.
+ * Takes the REGM4XEN bit into consideration, which is needed for the
+ * OMAP4 ABE DPLL. Returns the DPLL's output rate (before M-dividers)
+ * upon success, or 0 upon error.
+ */
+unsigned long omap4_dpll_regm4xen_recalc(struct clk *clk)
+{
+ u32 v;
+ unsigned long rate;
+ struct dpll_data *dd;
+
+ if (!clk || !clk->dpll_data)
+ return 0;
+
+ dd = clk->dpll_data;
+
+ rate = omap2_get_dpll_rate(clk);
+
+ /* regm4xen adds a multiplier of 4 to DPLL calculations */
+ v = __raw_readl(dd->control_reg);
+ if (v & OMAP4430_DPLL_REGM4XEN_MASK)
+ rate *= OMAP4430_REGM4XEN_MULT;
+
+ return rate;
+}
+
+/**
+ * omap4_dpll_regm4xen_round_rate - round DPLL rate, considering REGM4XEN bit
+ * @clk: struct clk * of the DPLL to round a rate for
+ * @target_rate: the desired rate of the DPLL
+ *
+ * Compute the rate that would be programmed into the DPLL hardware
+ * for @clk if set_rate() were to be provided with the rate
+ * @target_rate. Takes the REGM4XEN bit into consideration, which is
+ * needed for the OMAP4 ABE DPLL. Returns the rounded rate (before
+ * M-dividers) upon success, -EINVAL if @clk is null or not a DPLL, or
+ * ~0 if an error occurred in omap2_dpll_round_rate().
+ */
+long omap4_dpll_regm4xen_round_rate(struct clk *clk, unsigned long target_rate)
+{
+ u32 v;
+ struct dpll_data *dd;
+ long r;
+
+ if (!clk || !clk->dpll_data)
+ return -EINVAL;
+
+ dd = clk->dpll_data;
+
+ /* regm4xen adds a multiplier of 4 to DPLL calculations */
+ v = __raw_readl(dd->control_reg) & OMAP4430_DPLL_REGM4XEN_MASK;
+
+ if (v)
+ target_rate = target_rate / OMAP4430_REGM4XEN_MULT;
+
+ r = omap2_dpll_round_rate(clk, target_rate);
+ if (r == ~0)
+ return r;
+
+ if (v)
+ clk->dpll_data->last_rounded_rate *= OMAP4430_REGM4XEN_MULT;
+
+ return clk->dpll_data->last_rounded_rate;
+}
--
1.7.6.3
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