ARM: CSR: Adding CSR SiRFprimaII board support

SiRFprimaII is the latest generation application processor from CSR’s
Multifunction SoC product family. Designed around an ARM cortex A9 core,
high-speed memory bus, advanced 3D accelerator and full-HD multi-format
video decoder, SiRFprimaII is able to meet the needs of complicated
applications for modern multifunction devices that require heavy concurrent
applications and fluid user experience. Integrated with GPS baseband,
analog and PMU, this new platform is designed to provide a cost effective
solution for Automotive and Consumer markets.

This patch adds the basic support for this SoC and EVB board based on device
tree. It is following the ZYNQ of Xilinx in some degree.

Signed-off-by: Binghua Duan <Binghua.Duan@csr.com>
Signed-off-by: Rongjun Ying <Rongjun.Ying@csr.com>
Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Yuping Luo <Yuping.Luo@csr.com>
Signed-off-by: Bin Shi <Bin.Shi@csr.com>
Signed-off-by: Huayi Li <Huayi.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/mach-prima2/clock.c b/arch/arm/mach-prima2/clock.c
new file mode 100644
index 0000000..f9a2aaf
--- /dev/null
+++ b/arch/arm/mach-prima2/clock.c
@@ -0,0 +1,509 @@
+/*
+ * Clock tree for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/clkdev.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <asm/mach/map.h>
+#include <mach/map.h>
+
+#define SIRFSOC_CLKC_CLK_EN0    0x0000
+#define SIRFSOC_CLKC_CLK_EN1    0x0004
+#define SIRFSOC_CLKC_REF_CFG    0x0014
+#define SIRFSOC_CLKC_CPU_CFG    0x0018
+#define SIRFSOC_CLKC_MEM_CFG    0x001c
+#define SIRFSOC_CLKC_SYS_CFG    0x0020
+#define SIRFSOC_CLKC_IO_CFG     0x0024
+#define SIRFSOC_CLKC_DSP_CFG    0x0028
+#define SIRFSOC_CLKC_GFX_CFG    0x002c
+#define SIRFSOC_CLKC_MM_CFG     0x0030
+#define SIRFSOC_LKC_LCD_CFG     0x0034
+#define SIRFSOC_CLKC_MMC_CFG    0x0038
+#define SIRFSOC_CLKC_PLL1_CFG0  0x0040
+#define SIRFSOC_CLKC_PLL2_CFG0  0x0044
+#define SIRFSOC_CLKC_PLL3_CFG0  0x0048
+#define SIRFSOC_CLKC_PLL1_CFG1  0x004c
+#define SIRFSOC_CLKC_PLL2_CFG1  0x0050
+#define SIRFSOC_CLKC_PLL3_CFG1  0x0054
+#define SIRFSOC_CLKC_PLL1_CFG2  0x0058
+#define SIRFSOC_CLKC_PLL2_CFG2  0x005c
+#define SIRFSOC_CLKC_PLL3_CFG2  0x0060
+
+#define SIRFSOC_CLOCK_VA_BASE		SIRFSOC_VA(0x005000)
+
+#define KHZ     1000
+#define MHZ     (KHZ * KHZ)
+
+struct clk_ops {
+	unsigned long (*get_rate)(struct clk *clk);
+	long (*round_rate)(struct clk *clk, unsigned long rate);
+	int (*set_rate)(struct clk *clk, unsigned long rate);
+	int (*enable)(struct clk *clk);
+	int (*disable)(struct clk *clk);
+	struct clk *(*get_parent)(struct clk *clk);
+	int (*set_parent)(struct clk *clk, struct clk *parent);
+};
+
+struct clk {
+	struct clk *parent;     /* parent clk */
+	unsigned long rate;     /* clock rate in Hz */
+	signed char usage;      /* clock enable count */
+	signed char enable_bit; /* enable bit: 0 ~ 63 */
+	unsigned short regofs;  /* register offset */
+	struct clk_ops *ops;    /* clock operation */
+};
+
+static DEFINE_SPINLOCK(clocks_lock);
+
+static inline unsigned long clkc_readl(unsigned reg)
+{
+	return readl(SIRFSOC_CLOCK_VA_BASE + reg);
+}
+
+static inline void clkc_writel(u32 val, unsigned reg)
+{
+	writel(val, SIRFSOC_CLOCK_VA_BASE + reg);
+}
+
+/*
+ * osc_rtc - real time oscillator - 32.768KHz
+ * osc_sys - high speed oscillator - 26MHz
+ */
+
+static struct clk clk_rtc = {
+	.rate = 32768,
+};
+
+static struct clk clk_osc = {
+	.rate = 26 * MHZ,
+};
+
+/*
+ * std pll
+ */
+static unsigned long std_pll_get_rate(struct clk *clk)
+{
+	unsigned long fin = clk_get_rate(clk->parent);
+	u32 regcfg2 = clk->regofs + SIRFSOC_CLKC_PLL1_CFG2 -
+		SIRFSOC_CLKC_PLL1_CFG0;
+
+	if (clkc_readl(regcfg2) & BIT(2)) {
+		/* pll bypass mode */
+		clk->rate = fin;
+	} else {
+		/* fout = fin * nf / nr / od */
+		u32 cfg0 = clkc_readl(clk->regofs);
+		u32 nf = (cfg0 & (BIT(13) - 1)) + 1;
+		u32 nr = ((cfg0 >> 13) & (BIT(6) - 1)) + 1;
+		u32 od = ((cfg0 >> 19) & (BIT(4) - 1)) + 1;
+		WARN_ON(fin % MHZ);
+		clk->rate = fin / MHZ * nf / nr / od * MHZ;
+	}
+
+	return clk->rate;
+}
+
+static int std_pll_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long fin, nf, nr, od, reg;
+
+	/*
+	 * fout = fin * nf / (nr * od);
+	 * set od = 1, nr = fin/MHz, so fout = nf * MHz
+	 */
+
+	nf = rate / MHZ;
+	if (unlikely((rate % MHZ) || nf > BIT(13) || nf < 1))
+		return -EINVAL;
+
+	fin = clk_get_rate(clk->parent);
+	BUG_ON(fin < MHZ);
+
+	nr = fin / MHZ;
+	BUG_ON((fin % MHZ) || nr > BIT(6));
+
+	od = 1;
+
+	reg = (nf - 1) | ((nr - 1) << 13) | ((od - 1) << 19);
+	clkc_writel(reg, clk->regofs);
+
+	reg = clk->regofs + SIRFSOC_CLKC_PLL1_CFG1 - SIRFSOC_CLKC_PLL1_CFG0;
+	clkc_writel((nf >> 1) - 1, reg);
+
+	reg = clk->regofs + SIRFSOC_CLKC_PLL1_CFG2 - SIRFSOC_CLKC_PLL1_CFG0;
+	while (!(clkc_readl(reg) & BIT(6)))
+		cpu_relax();
+
+	clk->rate = 0; /* set to zero will force recalculation */
+	return 0;
+}
+
+static struct clk_ops std_pll_ops = {
+	.get_rate = std_pll_get_rate,
+	.set_rate = std_pll_set_rate,
+};
+
+static struct clk clk_pll1 = {
+	.parent = &clk_osc,
+	.regofs = SIRFSOC_CLKC_PLL1_CFG0,
+	.ops = &std_pll_ops,
+};
+
+static struct clk clk_pll2 = {
+	.parent = &clk_osc,
+	.regofs = SIRFSOC_CLKC_PLL2_CFG0,
+	.ops = &std_pll_ops,
+};
+
+static struct clk clk_pll3 = {
+	.parent = &clk_osc,
+	.regofs = SIRFSOC_CLKC_PLL3_CFG0,
+	.ops = &std_pll_ops,
+};
+
+/*
+ * clock domains - cpu, mem, sys/io
+ */
+
+static struct clk clk_mem;
+
+static struct clk *dmn_get_parent(struct clk *clk)
+{
+	struct clk *clks[] = {
+		&clk_osc, &clk_rtc, &clk_pll1, &clk_pll2, &clk_pll3
+	};
+	u32 cfg = clkc_readl(clk->regofs);
+	WARN_ON((cfg & (BIT(3) - 1)) > 4);
+	return clks[cfg & (BIT(3) - 1)];
+}
+
+static int dmn_set_parent(struct clk *clk, struct clk *parent)
+{
+	const struct clk *clks[] = {
+		&clk_osc, &clk_rtc, &clk_pll1, &clk_pll2, &clk_pll3
+	};
+	u32 cfg = clkc_readl(clk->regofs);
+	int i;
+	for (i = 0; i < ARRAY_SIZE(clks); i++) {
+		if (clks[i] == parent) {
+			cfg &= ~(BIT(3) - 1);
+			clkc_writel(cfg | i, clk->regofs);
+			/* BIT(3) - switching status: 1 - busy, 0 - done */
+			while (clkc_readl(clk->regofs) & BIT(3))
+				cpu_relax();
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static unsigned long dmn_get_rate(struct clk *clk)
+{
+	unsigned long fin = clk_get_rate(clk->parent);
+	u32 cfg = clkc_readl(clk->regofs);
+	if (cfg & BIT(24)) {
+		/* fcd bypass mode */
+		clk->rate = fin;
+	} else {
+		/*
+		 * wait count: bit[19:16], hold count: bit[23:20]
+		 */
+		u32 wait = (cfg >> 16) & (BIT(4) - 1);
+		u32 hold = (cfg >> 20) & (BIT(4) - 1);
+
+		clk->rate = fin / (wait + hold + 2);
+	}
+
+	return clk->rate;
+}
+
+static int dmn_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long fin;
+	unsigned ratio, wait, hold, reg;
+	unsigned bits = (clk == &clk_mem) ? 3 : 4;
+
+	fin = clk_get_rate(clk->parent);
+	ratio = fin / rate;
+
+	if (unlikely(ratio < 2 || ratio > BIT(bits + 1)))
+		return -EINVAL;
+
+	WARN_ON(fin % rate);
+
+	wait = (ratio >> 1) - 1;
+	hold = ratio - wait - 2;
+
+	reg = clkc_readl(clk->regofs);
+	reg &= ~(((BIT(bits) - 1) << 16) | ((BIT(bits) - 1) << 20));
+	reg |= (wait << 16) | (hold << 20) | BIT(25);
+	clkc_writel(reg, clk->regofs);
+
+	/* waiting FCD been effective */
+	while (clkc_readl(clk->regofs) & BIT(25))
+		cpu_relax();
+
+	clk->rate = 0; /* set to zero will force recalculation */
+
+	return 0;
+}
+
+/*
+ * cpu clock has no FCD register in Prima2, can only change pll
+ */
+static int cpu_set_rate(struct clk *clk, unsigned long rate)
+{
+	int ret1, ret2;
+	struct clk *cur_parent, *tmp_parent;
+
+	cur_parent = dmn_get_parent(clk);
+	BUG_ON(cur_parent == NULL || cur_parent->usage > 1);
+
+	/* switch to tmp pll before setting parent clock's rate */
+	tmp_parent = cur_parent == &clk_pll1 ? &clk_pll2 : &clk_pll1;
+	ret1 = dmn_set_parent(clk, tmp_parent);
+	BUG_ON(ret1);
+
+	ret2 = clk_set_rate(cur_parent, rate);
+
+	ret1 = dmn_set_parent(clk, cur_parent);
+
+	clk->rate = 0; /* set to zero will force recalculation */
+
+	return ret2 ? ret2 : ret1;
+}
+
+static struct clk_ops cpu_ops = {
+	.get_parent = dmn_get_parent,
+	.set_parent = dmn_set_parent,
+	.set_rate = cpu_set_rate,
+};
+
+static struct clk clk_cpu = {
+	.parent = &clk_pll1,
+	.regofs = SIRFSOC_CLKC_CPU_CFG,
+	.ops = &cpu_ops,
+};
+
+
+static struct clk_ops msi_ops = {
+	.set_rate = dmn_set_rate,
+	.get_rate = dmn_get_rate,
+	.set_parent = dmn_set_parent,
+	.get_parent = dmn_get_parent,
+};
+
+static struct clk clk_mem = {
+	.parent = &clk_pll2,
+	.regofs = SIRFSOC_CLKC_MEM_CFG,
+	.ops = &msi_ops,
+};
+
+static struct clk clk_sys = {
+	.parent = &clk_pll3,
+	.regofs = SIRFSOC_CLKC_SYS_CFG,
+	.ops = &msi_ops,
+};
+
+static struct clk clk_io = {
+	.parent = &clk_pll3,
+	.regofs = SIRFSOC_CLKC_IO_CFG,
+	.ops = &msi_ops,
+};
+
+/*
+ * on-chip clock sets
+ */
+static struct clk_lookup onchip_clks[] = {
+	{
+		.dev_id = "rtc",
+		.clk = &clk_rtc,
+	}, {
+		.dev_id = "osc",
+		.clk = &clk_osc,
+	}, {
+		.dev_id = "pll1",
+		.clk = &clk_pll1,
+	}, {
+		.dev_id = "pll2",
+		.clk = &clk_pll2,
+	}, {
+		.dev_id = "pll3",
+		.clk = &clk_pll3,
+	}, {
+		.dev_id = "cpu",
+		.clk = &clk_cpu,
+	}, {
+		.dev_id = "mem",
+		.clk = &clk_mem,
+	}, {
+		.dev_id = "sys",
+			.clk = &clk_sys,
+	}, {
+		.dev_id = "io",
+			.clk = &clk_io,
+	},
+};
+
+int clk_enable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return -EINVAL;
+
+	if (clk->parent)
+		clk_enable(clk->parent);
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	if (!clk->usage++ && clk->ops && clk->ops->enable)
+		clk->ops->enable(clk);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return;
+
+	WARN_ON(!clk->usage);
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	if (--clk->usage == 0 && clk->ops && clk->ops->disable)
+		clk->ops->disable(clk);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	if (clk->parent)
+		clk_disable(clk->parent);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return 0;
+
+	if (clk->rate)
+		return clk->rate;
+
+	if (clk->ops && clk->ops->get_rate)
+		return clk->ops->get_rate(clk);
+
+	return clk_get_rate(clk->parent);
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return 0;
+
+	if (clk->ops && clk->ops->round_rate)
+		return clk->ops->round_rate(clk, rate);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return -EINVAL;
+
+	if (!clk->ops || !clk->ops->set_rate)
+		return -EINVAL;
+
+	return clk->ops->set_rate(clk, rate);
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	int ret;
+	unsigned long flags;
+
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return -EINVAL;
+
+	if (!clk->ops || !clk->ops->set_parent)
+		return -EINVAL;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	ret = clk->ops->set_parent(clk, parent);
+	if (!ret) {
+		parent->usage += clk->usage;
+		clk->parent->usage -= clk->usage;
+		BUG_ON(clk->parent->usage < 0);
+		clk->parent = parent;
+	}
+	spin_unlock_irqrestore(&clocks_lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (unlikely(IS_ERR_OR_NULL(clk)))
+		return NULL;
+
+	if (!clk->ops || !clk->ops->get_parent)
+		return clk->parent;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	clk->parent = clk->ops->get_parent(clk);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+	return clk->parent;
+}
+EXPORT_SYMBOL(clk_get_parent);
+
+static void __init sirfsoc_clk_init(void)
+{
+	clkdev_add_table(onchip_clks, ARRAY_SIZE(onchip_clks));
+}
+
+static struct of_device_id clkc_ids[] = {
+	{ .compatible = "sirf,prima2-clkc" },
+};
+
+void __init sirfsoc_of_clk_init(void)
+{
+	struct device_node *np;
+	struct resource res;
+	struct map_desc sirfsoc_clkc_iodesc = {
+		.virtual = SIRFSOC_CLOCK_VA_BASE,
+		.type    = MT_DEVICE,
+	};
+
+	np = of_find_matching_node(NULL, clkc_ids);
+	if (!np)
+		panic("unable to find compatible clkc node in dtb\n");
+
+	if (of_address_to_resource(np, 0, &res))
+		panic("unable to find clkc range in dtb");
+	of_node_put(np);
+
+	sirfsoc_clkc_iodesc.pfn = __phys_to_pfn(res.start);
+	sirfsoc_clkc_iodesc.length = 1 + res.end - res.start;
+
+	iotable_init(&sirfsoc_clkc_iodesc, 1);
+
+	sirfsoc_clk_init();
+}