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openwrt/target/linux/xburst/patches-3.8/0011-MIPS-JZ4740-Added-sett...

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From 27ff621cd9a5347efda4be502abbef13a99146ce Mon Sep 17 00:00:00 2001
From: Maarten ter Huurne <maarten@treewalker.org>
Date: Sun, 29 Aug 2010 08:11:00 +0200
Subject: [PATCH 11/21] MIPS: JZ4740: Added setting of PLL rate and main
dividers.
This functionality makes a cpufreq driver possible.
Squashed version of the development done in the jz-2.6.39 branch.
---
arch/mips/jz4740/clock.c | 230 ++++++++++++++++++++++++++++++++++++++++++++--
arch/mips/jz4740/clock.h | 4 +
2 files changed, 224 insertions(+), 10 deletions(-)
--- a/arch/mips/jz4740/clock.c
+++ b/arch/mips/jz4740/clock.c
@@ -1,5 +1,8 @@
/*
+ * Copyright (c) 2006-2007, Ingenic Semiconductor Inc.
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ * Copyright (c) 2010, Ulrich Hecht <ulrich.hecht@gmail.com>
+ * Copyright (c) 2010, Maarten ter Huurne <maarten@treewalker.org>
* JZ4740 SoC clock support
*
* This program is free software; you can redistribute it and/or modify it
@@ -41,16 +44,20 @@
#define JZ_CLOCK_CTRL_I2S_SRC_PLL BIT(31)
#define JZ_CLOCK_CTRL_KO_ENABLE BIT(30)
#define JZ_CLOCK_CTRL_UDC_SRC_PLL BIT(29)
-#define JZ_CLOCK_CTRL_UDIV_MASK 0x1f800000
#define JZ_CLOCK_CTRL_CHANGE_ENABLE BIT(22)
#define JZ_CLOCK_CTRL_PLL_HALF BIT(21)
-#define JZ_CLOCK_CTRL_LDIV_MASK 0x001f0000
#define JZ_CLOCK_CTRL_UDIV_OFFSET 23
#define JZ_CLOCK_CTRL_LDIV_OFFSET 16
#define JZ_CLOCK_CTRL_MDIV_OFFSET 12
#define JZ_CLOCK_CTRL_PDIV_OFFSET 8
#define JZ_CLOCK_CTRL_HDIV_OFFSET 4
#define JZ_CLOCK_CTRL_CDIV_OFFSET 0
+#define JZ_CLOCK_CTRL_UDIV_MASK (0x3f << JZ_CLOCK_CTRL_UDIV_OFFSET)
+#define JZ_CLOCK_CTRL_LDIV_MASK (0x1f << JZ_CLOCK_CTRL_LDIV_OFFSET)
+#define JZ_CLOCK_CTRL_MDIV_MASK (0x0f << JZ_CLOCK_CTRL_MDIV_OFFSET)
+#define JZ_CLOCK_CTRL_PDIV_MASK (0x0f << JZ_CLOCK_CTRL_PDIV_OFFSET)
+#define JZ_CLOCK_CTRL_HDIV_MASK (0x0f << JZ_CLOCK_CTRL_HDIV_OFFSET)
+#define JZ_CLOCK_CTRL_CDIV_MASK (0x0f << JZ_CLOCK_CTRL_CDIV_OFFSET)
#define JZ_CLOCK_GATE_UART0 BIT(0)
#define JZ_CLOCK_GATE_TCU BIT(1)
@@ -90,6 +97,7 @@
#define JZ_CLOCK_PLL_M_OFFSET 23
#define JZ_CLOCK_PLL_N_OFFSET 18
#define JZ_CLOCK_PLL_OD_OFFSET 16
+#define JZ_CLOCK_PLL_STABILIZE_OFFSET 0
#define JZ_CLOCK_LOW_POWER_MODE_DOZE BIT(2)
#define JZ_CLOCK_LOW_POWER_MODE_SLEEP BIT(0)
@@ -97,10 +105,15 @@
#define JZ_CLOCK_SLEEP_CTRL_SUSPEND_UHC BIT(7)
#define JZ_CLOCK_SLEEP_CTRL_ENABLE_UDC BIT(6)
+#define JZ_REG_EMC_RTCNT 0x88
+#define JZ_REG_EMC_RTCOR 0x8C
+
static void __iomem *jz_clock_base;
static spinlock_t jz_clock_lock;
static LIST_HEAD(jz_clocks);
+static void __iomem *jz_emc_base;
+
struct main_clk {
struct clk clk;
uint32_t div_offset;
@@ -204,25 +217,88 @@ static int jz_clk_ko_is_enabled(struct c
return !!(jz_clk_reg_read(JZ_REG_CLOCK_CTRL) & JZ_CLOCK_CTRL_KO_ENABLE);
}
+static struct static_clk jz_clk_ext;
+
+static unsigned long jz_clk_pll_calc_rate(
+ unsigned int in_div, unsigned int feedback, unsigned int out_div)
+{
+ return ((jz_clk_ext.rate / in_div) * feedback) / out_div;
+}
+
+static void jz_clk_pll_calc_dividers(unsigned long rate,
+ unsigned int *in_div, unsigned int *feedback, unsigned int *out_div)
+{
+ unsigned int target;
+
+ /* The frequency after the input divider must be between 1 and 15 MHz.
+ The highest divider yields the best resolution. */
+ *in_div = jz_clk_ext.rate / 1000000;
+ if (*in_div >= 34)
+ *in_div = 33;
+
+ /* The frequency before the output divider must be between 100 and
+ 500 MHz. The lowest target rate is more energy efficient. */
+ if (rate < 25000000) {
+ *out_div = 4;
+ target = 25000000 * 4;
+ } else if (rate <= 50000000) {
+ *out_div = 4;
+ target = rate * 4;
+ } else if (rate <= 100000000) {
+ *out_div = 2;
+ target = rate * 2;
+ } else if (rate <= 500000000) {
+ *out_div = 1;
+ target = rate;
+ } else {
+ *out_div = 1;
+ target = 500000000;
+ }
+
+ /* Compute the feedback divider.
+ Since the divided input is at least 1 MHz and the target frequency
+ at most 500 MHz, the feedback will be at most 500 and will therefore
+ always fit in the 9-bit register.
+ Similarly, the divided input is at most 15 MHz and the target
+ frequency at least 100 MHz, so the feedback will be at least 6
+ where the minimum supported value is 2. */
+ *feedback = ((target / 1000) * *in_div) / (jz_clk_ext.rate / 1000);
+}
+
+static unsigned long jz_clk_pll_round_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned int in_div, feedback, out_div;
+ /* The PLL frequency must be a multiple of 24 MHz, since the LCD pixel
+ * clock must be exactly 12 MHz for the TV-out to work.
+ * TODO: A multiple of 12 MHz for the PLL would work if the PLL would
+ * not be divided by 2 before being passed to the set of derived
+ * clocks that includes the LCD pixel clock.
+ * TODO: Systemwide decisions like this should be made by the board
+ * support code, so add some kind of hook for that.
+ */
+ unsigned long rate24 = (rate / 24000000) * 24000000;
+
+ jz_clk_pll_calc_dividers(rate24, &in_div, &feedback, &out_div);
+ return jz_clk_pll_calc_rate(in_div, feedback, out_div);
+}
+
static const int pllno[] = {1, 2, 2, 4};
static unsigned long jz_clk_pll_get_rate(struct clk *clk)
{
uint32_t val;
- int m;
- int n;
- int od;
+ unsigned int in_div, feedback, out_div;
val = jz_clk_reg_read(JZ_REG_CLOCK_PLL);
if (val & JZ_CLOCK_PLL_BYPASS)
return clk_get_rate(clk->parent);
- m = ((val >> 23) & 0x1ff) + 2;
- n = ((val >> 18) & 0x1f) + 2;
- od = (val >> 16) & 0x3;
+ feedback = ((val >> 23) & 0x1ff) + 2;
+ in_div = ((val >> 18) & 0x1f) + 2;
+ out_div = pllno[(val >> 16) & 0x3];
- return ((clk_get_rate(clk->parent) / n) * m) / pllno[od];
+ return jz_clk_pll_calc_rate(in_div, feedback, out_div);
}
static unsigned long jz_clk_pll_half_get_rate(struct clk *clk)
@@ -235,7 +311,77 @@ static unsigned long jz_clk_pll_half_get
return jz_clk_pll_get_rate(clk->parent) >> 1;
}
-static const int jz_clk_main_divs[] = {1, 2, 3, 4, 6, 8, 12, 16, 24, 32};
+#define SDRAM_TREF 15625 /* Refresh period: 4096 refresh cycles/64ms */
+
+static void sdram_set_pll(unsigned int pllin)
+{
+ unsigned int ns, sdramclock;
+
+ ns = 1000000000 / pllin;
+ sdramclock = (SDRAM_TREF / ns) / 64 + 1;
+ if (sdramclock > 0xff) sdramclock = 0xff;
+ /* Set refresh registers */
+ writew(sdramclock, jz_emc_base + JZ_REG_EMC_RTCOR);
+ writew(sdramclock, jz_emc_base + JZ_REG_EMC_RTCNT);
+}
+
+static int jz_clk_pll_set_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned int ctrl, plcr1;
+ unsigned int feedback, in_div, out_div, pllout, pllout2;
+
+ jz_clk_pll_calc_dividers(rate, &in_div, &feedback, &out_div);
+
+ ctrl = jz_clk_reg_read(JZ_REG_CLOCK_CTRL);
+ pllout = jz_clk_pll_calc_rate(in_div, feedback, out_div);
+ pllout2 = (ctrl & JZ_CLOCK_CTRL_PLL_HALF) ? pllout : (pllout / 2);
+
+ /* Init UHC clock */
+ writel(pllout2 / 48000000 - 1, jz_clock_base + JZ_REG_CLOCK_UHC);
+
+ plcr1 = ((feedback - 2) << JZ_CLOCK_PLL_M_OFFSET) |
+ ((in_div - 2) << JZ_CLOCK_PLL_N_OFFSET) |
+ ((out_div - 1) << JZ_CLOCK_PLL_OD_OFFSET) |
+ (0x20 << JZ_CLOCK_PLL_STABILIZE_OFFSET) |
+ JZ_CLOCK_PLL_ENABLED;
+
+ sdram_set_pll(pllout);
+
+ /* LCD pixclock */
+ writel(pllout2 / 12000000 - 1, jz_clock_base + JZ_REG_CLOCK_LCD);
+
+ /* configure PLL */
+ __asm__ __volatile__(
+ ".set noreorder\n\t"
+ ".align 5\n"
+ "sw %1,0(%0)\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ ".set reorder\n\t"
+ :
+ : "r" (jz_clock_base + JZ_REG_CLOCK_PLL), "r" (plcr1));
+
+ /* MtH: For some reason the MSC will have problems if this flag is not
+ restored, even though the MSC is supposedly the only divider
+ that is not affected by this flag. */
+ jz_clk_reg_set_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_CHANGE_ENABLE);
+
+ return 0;
+}
+
+static const unsigned int jz_clk_main_divs[] = {
+ 1, 2, 3, 4, 6, 8, 12, 16, 24, 32
+};
+static const unsigned int jz_clk_main_divs_inv[] = {
+ -1, 0, 1, 2, 3, -1, 4, -1, 5, -1, -1, -1, 6, -1, -1, -1,
+ 7, -1, -1, -1, -1, -1, -1, -1, 8, -1, -1, -1, -1, -1, -1, -1,
+ 9
+};
static unsigned long jz_clk_main_round_rate(struct clk *clk, unsigned long rate)
{
@@ -290,6 +436,64 @@ static int jz_clk_main_set_rate(struct c
return 0;
}
+static struct main_clk jz_clk_cpu;
+
+int clk_main_set_dividers(bool immediate, unsigned int cdiv, unsigned int hdiv,
+ unsigned int mdiv, unsigned int pdiv)
+{
+ unsigned int cdiv_enc, hdiv_enc, mdiv_enc, pdiv_enc;
+ unsigned int ctrl;
+ unsigned int tmp, wait;
+
+ if (cdiv >= ARRAY_SIZE(jz_clk_main_divs_inv) ||
+ hdiv >= ARRAY_SIZE(jz_clk_main_divs_inv) ||
+ mdiv >= ARRAY_SIZE(jz_clk_main_divs_inv) ||
+ pdiv >= ARRAY_SIZE(jz_clk_main_divs_inv))
+ return -EINVAL;
+ cdiv_enc = jz_clk_main_divs_inv[cdiv];
+ hdiv_enc = jz_clk_main_divs_inv[hdiv];
+ mdiv_enc = jz_clk_main_divs_inv[mdiv];
+ pdiv_enc = jz_clk_main_divs_inv[pdiv];
+ if (cdiv_enc == (unsigned int)-1 ||
+ hdiv_enc == (unsigned int)-1 ||
+ mdiv_enc == (unsigned int)-1 ||
+ pdiv_enc == (unsigned int)-1)
+ return -EINVAL;
+
+ ctrl = jz_clk_reg_read(JZ_REG_CLOCK_CTRL);
+ ctrl &= ~(JZ_CLOCK_CTRL_CHANGE_ENABLE |
+ JZ_CLOCK_CTRL_CDIV_MASK | JZ_CLOCK_CTRL_HDIV_MASK |
+ JZ_CLOCK_CTRL_MDIV_MASK | JZ_CLOCK_CTRL_PDIV_MASK);
+ if (immediate) ctrl |= JZ_CLOCK_CTRL_CHANGE_ENABLE;
+ ctrl |= (cdiv_enc << JZ_CLOCK_CTRL_CDIV_OFFSET) |
+ (hdiv_enc << JZ_CLOCK_CTRL_HDIV_OFFSET) |
+ (mdiv_enc << JZ_CLOCK_CTRL_MDIV_OFFSET) |
+ (pdiv_enc << JZ_CLOCK_CTRL_PDIV_OFFSET);
+
+ /* set dividers */
+ /* delay loops lifted from the old Ingenic cpufreq driver */
+ wait = ((clk_get_rate(&jz_clk_cpu.clk) / 1000000) * 500) / 1000;
+ __asm__ __volatile__(
+ ".set noreorder\n\t"
+ ".align 5\n"
+ "sw %2,0(%1)\n\t"
+ "li %0,0\n\t"
+ "1:\n\t"
+ "bne %0,%3,1b\n\t"
+ "addi %0, 1\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ ".set reorder\n\t"
+ : "=r" (tmp)
+ : "r" (jz_clock_base + JZ_REG_CLOCK_CTRL), "r" (ctrl),
+ "r" (wait));
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(clk_main_set_dividers);
+
static struct clk_ops jz_clk_static_ops = {
.get_rate = jz_clk_static_get_rate,
.enable = jz_clk_enable_gating,
@@ -307,6 +511,8 @@ static struct static_clk jz_clk_ext = {
static struct clk_ops jz_clk_pll_ops = {
.get_rate = jz_clk_pll_get_rate,
+ .set_rate = jz_clk_pll_set_rate,
+ .round_rate = jz_clk_pll_round_rate,
};
static struct clk jz_clk_pll = {
@@ -897,6 +1103,10 @@ static int jz4740_clock_init(void)
if (!jz_clock_base)
return -EBUSY;
+ jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
+ if (!jz_emc_base)
+ return -EBUSY;
+
spin_lock_init(&jz_clock_lock);
jz_clk_ext.rate = jz4740_clock_bdata.ext_rate;
--- a/arch/mips/jz4740/clock.h
+++ b/arch/mips/jz4740/clock.h
@@ -17,6 +17,7 @@
#define __MIPS_JZ4740_CLOCK_H__
#include <linux/list.h>
+#include <linux/types.h>
struct jz4740_clock_board_data {
unsigned long ext_rate;
@@ -63,6 +64,9 @@ struct clk {
int clk_is_enabled(struct clk *clk);
+int clk_main_set_dividers(bool immediate, unsigned int cdiv, unsigned int hdiv,
+ unsigned int mdiv, unsigned int pdiv);
+
#ifdef CONFIG_DEBUG_FS
void jz4740_clock_debugfs_init(void);
void jz4740_clock_debugfs_add_clk(struct clk *clk);
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