[PATCH V2 41/69] SPEAr Clock Framework: Adding support for PLL frequency change

[Viresh KUMAR <viresh.kumar-qxv4g6HH51o@public.gmane.org>]

From: Deepak Sikri <deepak.sikri-qxv4g6HH51o@public.gmane.org>

Signed-off-by: Deepak Sikri <deepak.sikri-qxv4g6HH51o@public.gmane.org>
Signed-off-by: Rajeev Kumar <rajeev-dlh.kumar-qxv4g6HH51o@public.gmane.org>
Signed-off-by: Viresh Kumar <viresh.kumar-qxv4g6HH51o@public.gmane.org>
---
 arch/arm/mach-spear3xx/spear3xx.c        |    5 +
 arch/arm/mach-spear6xx/spear6xx.c        |    5 +
 arch/arm/plat-spear/Makefile             |    2 +-
 arch/arm/plat-spear/clock.c              |    6 +-
 arch/arm/plat-spear/include/plat/clock.h |    1 +
 arch/arm/plat-spear/pll_clk.S            |  187 ++++++++++++++++++++++++++++++
 6 files changed, 201 insertions(+), 5 deletions(-)
 create mode 100644 arch/arm/plat-spear/pll_clk.S

diff --git a/arch/arm/mach-spear3xx/spear3xx.c b/arch/arm/mach-spear3xx/spear3xx.c
index dcbe020..c9727ac 100644
--- a/arch/arm/mach-spear3xx/spear3xx.c
+++ b/arch/arm/mach-spear3xx/spear3xx.c
@@ -271,6 +271,11 @@ struct map_desc spear3xx_io_desc[] __initdata = {
 		.pfn		= __phys_to_pfn(SPEAR3XX_ICM3_MISC_REG_BASE),
 		.length		= SZ_4K,
 		.type		= MT_DEVICE
+	}, {
+		.virtual	= IO_ADDRESS(SPEAR3XX_ICM3_SDRAM_CTRL_BASE),
+		.pfn		= __phys_to_pfn(SPEAR3XX_ICM3_SDRAM_CTRL_BASE),
+		.length		= SZ_4K,
+		.type		= MT_DEVICE
 	},
 };
 
diff --git a/arch/arm/mach-spear6xx/spear6xx.c b/arch/arm/mach-spear6xx/spear6xx.c
index cd2153c..cc2692e 100644
--- a/arch/arm/mach-spear6xx/spear6xx.c
+++ b/arch/arm/mach-spear6xx/spear6xx.c
@@ -430,6 +430,11 @@ static struct map_desc spear6xx_io_desc[] __initdata = {
 		.pfn		= __phys_to_pfn(SPEAR6XX_ICM3_MISC_REG_BASE),
 		.length		= SZ_4K,
 		.type		= MT_DEVICE
+	}, {
+		.virtual	= IO_ADDRESS(SPEAR6XX_ICM3_SDRAM_CTRL_BASE),
+		.pfn		= __phys_to_pfn(SPEAR6XX_ICM3_SDRAM_CTRL_BASE),
+		.length		= SZ_4K,
+		.type		= MT_DEVICE
 	},
 };
 
diff --git a/arch/arm/plat-spear/Makefile b/arch/arm/plat-spear/Makefile
index 50c680c..0e2cf75 100644
--- a/arch/arm/plat-spear/Makefile
+++ b/arch/arm/plat-spear/Makefile
@@ -3,7 +3,7 @@
 #
 
 # Common support
-obj-y	:= clcd.o clock.o time.o smi.o
+obj-y	:= clcd.o clock.o pll_clk.o smi.o time.o
 
 obj-$(CONFIG_ARCH_SPEAR3XX)	+= shirq.o padmux.o
 obj-$(CONFIG_MACH_SPEAR310)	+= plgpio.o
diff --git a/arch/arm/plat-spear/clock.c b/arch/arm/plat-spear/clock.c
index fb1c87b..ee8f82b 100644
--- a/arch/arm/plat-spear/clock.c
+++ b/arch/arm/plat-spear/clock.c
@@ -586,11 +586,10 @@ int pll_clk_set_rate(struct clk *clk, unsigned long desired_rate)
 			 * call routine to put ddr in refresh mode, and
 			 * configure pll.
 			 */
-			/* TBD */
+			pll_set_rate(tbls[i].m, tbls[i].p, tbls[i].n);
 			clk->rate = rate;
 		}
-
-		return ret;
+		return 0;
 	}
 
 	val = readl(config->mode_reg) &
@@ -616,7 +615,6 @@ int pll_clk_set_rate(struct clk *clk, unsigned long desired_rate)
 			config->masks->norm_fdbk_m_shift;
 
 	writel(val, config->cfg_reg);
-
 	clk->rate = rate;
 
 	return 0;
diff --git a/arch/arm/plat-spear/include/plat/clock.h b/arch/arm/plat-spear/include/plat/clock.h
index 6ddcf93..00d6854 100644
--- a/arch/arm/plat-spear/include/plat/clock.h
+++ b/arch/arm/plat-spear/include/plat/clock.h
@@ -264,5 +264,6 @@ int aux_clk_set_rate(struct clk *clk, unsigned long desired_rate);
 unsigned long clcd_calc_rate(struct clk *clk, int index);
 int clcd_clk_recalc(struct clk *clk, unsigned long *rate, unsigned long prate);
 int clcd_clk_set_rate(struct clk *clk, unsigned long desired_rate);
+void pll_set_rate(u16 pdiv, u8 nmul, u8 hclkdiv);
 
 #endif /* __PLAT_CLOCK_H */
diff --git a/arch/arm/plat-spear/pll_clk.S b/arch/arm/plat-spear/pll_clk.S
new file mode 100644
index 0000000..d0687b4
--- /dev/null
+++ b/arch/arm/plat-spear/pll_clk.S
@@ -0,0 +1,187 @@
+/*
+ * arch/arm/plat-spear/pll_clk.S
+ *
+ * SPEAR3xx and SPEAR6xx specific functions that will run in
+ * cache. These funstions intend to configure the PLL.
+ *
+ * Copyright (ST) 2010 Deepak Sikri <deepak.sikri@.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <mach/hardware.h>
+#include <mach/suspend.h>
+
+#if defined(CONFIG_ARCH_SPEAR3XX) || defined(CONFIG_ARCH_SPEAR6XX)
+.text
+ENTRY(pll_set_rate)
+	stmfd	sp!, {r0-r12, lr}
+
+	/* Lock down the TLB entry to the current victim */
+	mrc	p15, 0, r3, c10, c0, 0	/* read the lockdown register */
+	orr	r3, r3, #1		/* set the preserved bit */
+	mcr	p15, 0, r3, c10, c0, 0	/* write to the lockdown register */
+
+	/*
+	 * set r4 to the value of the address to be locked down.
+	 * Invalidate the TLB single entry in TLB to ensure that
+	 * the locked address is not already in TLB.
+	 * MPMC, System Controller & Miscellaneous register address
+	 * are locked down below.
+	 */
+
+	ldr	r4, MPMC_BASE_VA
+	/* Invalidate the MPMC virtual address in TLB. */
+	mcr	p15, 0, r4, c8, c7, 1
+	/* TLB will miss and entry will be reloaded */
+	ldr	r4, [r4]
+	/* read the lockdown register (victim will have rloaded) */
+	mrc	p15, 0, r3, c10, c0, 0
+
+	ldr	r4, SYS_CTRL_BASE_VA
+	/* Invalidate the System controller virtual address in TLB */
+	mcr	p15, 0, r4, c8, c7, 1
+	/* TLB will miss and entry will be reloaded */
+	ldr	r4, [r4]
+	/* read the lockdown register (victim will have rloaded) */
+	mrc	p15, 0, r3, c10, c0, 0
+
+	ldr	r4, MISC_BASE_VA
+	/* Invalidate the Miscellaneous registers virtual address in TLB */
+	mcr	p15, 0, r4, c8, c7, 1
+	/* TLB will miss and entry will be reloaded */
+	ldr	r4, [r4]
+	/* read the lockdown register (victim will have rloaded) */
+	mrc	p15, 0, r3, c10, c0, 0
+
+	/* clear preserve bit */
+	bic	r3, r3, #1
+	/* write to the lockdown register */
+	mcr	p15, 0, r3, c10, c0, 0
+
+	ldr	r7, MPMC_BASE_VA
+	ldr	r8, SYS_CTRL_BASE_VA
+	ldr	r6, MISC_BASE_VA
+	/* Prefetch certain instructions in the cache. */
+	adr	r4, cache_prefetch_start1
+	adr	r5, cache_prefetch_end1
+	mvn	r3, #0x1F
+	ands	r4, r3, r4
+	/* Lock Instructions in i-cache */
+fetch_loop:
+	/*
+	 * copy a cache-line-sized block of main memory to a cache
+	 * line in the I-cache.
+	 */
+	mcr	p15, 0, r4, c7, c13, 1
+	cmp	r4, r5
+	addls	r4, r4, #0x20
+	bls	fetch_loop
+cache_prefetch_start1:
+	/* Put SDRAM in self-refresh mode */
+	ldr	r3, [r7, #0x1c]
+	/* Clear START bit(24) of MEMCTL_GP_03 register in MPMC */
+	ldr	r4, =0x1000000
+	bic	r3, r3, r4
+	str	r3, [r7, #0x1c]
+
+	ldr	r3, [r7, #0xe4]
+	ldr	r4, =0xffff0000
+	/* Latch the current self refresh time */
+	mov	r9, r3
+	/* Increase the self refresh exit time */
+	bic	r3, r3, r4
+	ldr	r4, =0xffff
+	/* Program the SDRAM self refresh exit time on read command */
+	orr	r3, r3, r4, LSL #16
+	str	r3, [r7, #0xe4]
+
+	ldr	r3, [r7, #0x1c]
+	/* Set the SREFRESH bit(16) */
+	ldr	r4, =0x10000
+	orr	r3, r3, r4
+	str	r3, [r7, #0x1c]
+
+	/* Put the system in slow mode, use system controller */
+	ldr	r3, [r8]
+	bic	r3, r3, #0x7
+	/* Set the apt mode bits(2:0) in SCCTRL register */
+	orr	r3, r3, #0x2
+	str	r3, [r8]
+
+wait_till_slow_mode:
+	ldr	r3, [r8]
+	and	r3, r3, #0x78	/* Wait for the mode to be updated */
+	cmp	r3, #0x10	/* Poll the SCCTRL register status bits (6:3) */
+	bne wait_till_slow_mode
+
+	/*
+	 * reprogram the m(r0), p(r2), n(r1) values in the PLL
+	 * control registers (PLL_FRQ register in misc space).
+	 */
+	ldr	r3, [r6, #0x0c]
+	bic	r3, r3, #0x00ff
+	/* Program the PLL post divisor: p */
+	orr	r3, r3, r2
+	str	r3, [r6, #0x0c]
+
+	ldr	r3, [r6, #0x0c]
+	ldr	r4, =0xffff0000
+	bic	r3, r3, r4
+	bic	r3, r3, #0x0700
+	/* Program the PLL pre divisor: n */
+	orr	r3, r3, r1, LSL #8
+	/* Program the PLL feedback divisor: m */
+	orr	r3, r3, r0, LSL #24
+	str	r3, [r6, #0x0c]
+
+	/* Move the system in Normal mode, use system controller */
+	ldr	r3, [r8, #0x0]
+	ldr	r4, =0xfffffff8
+	/* Set the apt mode bits(2:0) in SCCTRL register */
+	and	r3, r3, r4
+	orr	r3, r3, #0x4
+	str	r3, [r8, #0x0]
+
+wait_till_normal_mode:
+	ldr	r3, [r8, #0x0]
+	and	r3, r3, #0x78
+	cmp	r3, #0x20	/* Poll the SCCTRL register status bits (6:3) */
+	bne wait_till_normal_mode
+
+	/* Exit DDR-SDRAM from self-refresh mode */
+	ldr	r10, MPMC_BASE_VA
+	/* Clear the SREFRESH bit(16) */
+	ldr	r3, [r10, #0x1c]
+	ldr	r4, =0x10000
+	bic	r3, r3, r4
+	str	r3, [r10, #0x1c]
+	/* Restore the SDRAM self refresh exit time on read command */
+	mov	r3, r9
+	str	r3, [r7, #0xe4]
+	/* Begin the command processing in controller */
+	ldr	r4, =0x1000000
+	orr	r3, r3, r4
+	/* Set START bit(24) of MEMCTL_GP_03 register in MPMC*/
+	str	r3, [r10, #0x1c]
+
+	ldmfd	sp!, {r0-r12, pc}
+
+/* This is the end of the code to be copied */
+
+SYS_CTRL_BASE_VA :
+	.word IO_ADDRESS(SYS_CTRL_BASE_PA)
+MPMC_BASE_VA :
+	.word IO_ADDRESS(MPMC_BASE_PA)
+MISC_BASE_VA :
+	.word IO_ADDRESS(MISC_BASE_PA)
+cache_prefetch_end1 :
+
+#elif defined(CONFIG_ARCH_SPEAR13XX)
+.text
+ENTRY(pll_set_rate)
+#endif
-- 
1.7.2.2

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