ARM: 6014/1: ST SPEAr: Added clock framework for SPEAr platform and machines

Clock framework for SPEAr is based upon clkdev framework for ARM
Reviewed-by: Linus Walleij <linux.walleij@stericsson.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-spear3xx/clock.c

+/*
+ * arch/arm/mach-spear3xx/clock.c
+ *
+ * SPEAr3xx machines clock framework source file
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.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/init.h>
+#include <linux/kernel.h>
+#include <mach/misc_regs.h>
+#include <plat/clock.h>
+
+/* root clks */
+/* 32 KHz oscillator clock */
+static struct clk osc_32k_clk = {
+	.flags = ALWAYS_ENABLED,
+	.rate = 32000,
+};
+
+/* 24 MHz oscillator clock */
+static struct clk osc_24m_clk = {
+	.flags = ALWAYS_ENABLED,
+	.rate = 24000000,
+};
+
+/* clock derived from 32 KHz osc clk */
+/* rtc clock */
+static struct clk rtc_clk = {
+	.pclk = &osc_32k_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = RTC_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* clock derived from 24 MHz osc clk */
+/* pll1 configuration structure */
+static struct pll_clk_config pll1_config = {
+	.mode_reg = PLL1_CTR,
+	.cfg_reg = PLL1_FRQ,
+};
+
+/* PLL1 clock */
+static struct clk pll1_clk = {
+	.pclk = &osc_24m_clk,
+	.en_reg = PLL1_CTR,
+	.en_reg_bit = PLL_ENABLE,
+	.recalc = &pll1_clk_recalc,
+	.private_data = &pll1_config,
+};
+
+/* PLL3 48 MHz clock */
+static struct clk pll3_48m_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &osc_24m_clk,
+	.rate = 48000000,
+};
+
+/* watch dog timer clock */
+static struct clk wdt_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &osc_24m_clk,
+	.recalc = &follow_parent,
+};
+
+/* clock derived from pll1 clk */
+/* cpu clock */
+static struct clk cpu_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &pll1_clk,
+	.recalc = &follow_parent,
+};
+
+/* ahb configuration structure */
+static struct bus_clk_config ahb_config = {
+	.reg = CORE_CLK_CFG,
+	.mask = PLL_HCLK_RATIO_MASK,
+	.shift = PLL_HCLK_RATIO_SHIFT,
+};
+
+/* ahb clock */
+static struct clk ahb_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &pll1_clk,
+	.recalc = &bus_clk_recalc,
+	.private_data = &ahb_config,
+};
+
+/* uart configurations */
+static struct aux_clk_config uart_config = {
+	.synth_reg = UART_CLK_SYNT,
+};
+
+/* uart parents */
+static struct pclk_info uart_pclk_info[] = {
+	{
+		.pclk = &pll1_clk,
+		.pclk_mask = AUX_CLK_PLL1_MASK,
+		.scalable = 1,
+	}, {
+		.pclk = &pll3_48m_clk,
+		.pclk_mask = AUX_CLK_PLL3_MASK,
+		.scalable = 0,
+	},
+};
+
+/* uart parent select structure */
+static struct pclk_sel uart_pclk_sel = {
+	.pclk_info = uart_pclk_info,
+	.pclk_count = ARRAY_SIZE(uart_pclk_info),
+	.pclk_sel_reg = PERIP_CLK_CFG,
+	.pclk_sel_mask = UART_CLK_MASK,
+};
+
+/* uart clock */
+static struct clk uart_clk = {
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = UART_CLK_ENB,
+	.pclk_sel = &uart_pclk_sel,
+	.pclk_sel_shift = UART_CLK_SHIFT,
+	.recalc = &aux_clk_recalc,
+	.private_data = &uart_config,
+};
+
+/* firda configurations */
+static struct aux_clk_config firda_config = {
+	.synth_reg = FIRDA_CLK_SYNT,
+};
+
+/* firda parents */
+static struct pclk_info firda_pclk_info[] = {
+	{
+		.pclk = &pll1_clk,
+		.pclk_mask = AUX_CLK_PLL1_MASK,
+		.scalable = 1,
+	}, {
+		.pclk = &pll3_48m_clk,
+		.pclk_mask = AUX_CLK_PLL3_MASK,
+		.scalable = 0,
+	},
+};
+
+/* firda parent select structure */
+static struct pclk_sel firda_pclk_sel = {
+	.pclk_info = firda_pclk_info,
+	.pclk_count = ARRAY_SIZE(firda_pclk_info),
+	.pclk_sel_reg = PERIP_CLK_CFG,
+	.pclk_sel_mask = FIRDA_CLK_MASK,
+};
+
+/* firda clock */
+static struct clk firda_clk = {
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = FIRDA_CLK_ENB,
+	.pclk_sel = &firda_pclk_sel,
+	.pclk_sel_shift = FIRDA_CLK_SHIFT,
+	.recalc = &aux_clk_recalc,
+	.private_data = &firda_config,
+};
+
+/* gpt parents */
+static struct pclk_info gpt_pclk_info[] = {
+	{
+		.pclk = &pll1_clk,
+		.pclk_mask = AUX_CLK_PLL1_MASK,
+		.scalable = 1,
+	}, {
+		.pclk = &pll3_48m_clk,
+		.pclk_mask = AUX_CLK_PLL3_MASK,
+		.scalable = 0,
+	},
+};
+
+/* gpt parent select structure */
+static struct pclk_sel gpt_pclk_sel = {
+	.pclk_info = gpt_pclk_info,
+	.pclk_count = ARRAY_SIZE(gpt_pclk_info),
+	.pclk_sel_reg = PERIP_CLK_CFG,
+	.pclk_sel_mask = GPT_CLK_MASK,
+};
+
+/* gpt0 configurations */
+static struct aux_clk_config gpt0_config = {
+	.synth_reg = PRSC1_CLK_CFG,
+};
+
+/* gpt0 timer clock */
+static struct clk gpt0_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk_sel = &gpt_pclk_sel,
+	.pclk_sel_shift = GPT0_CLK_SHIFT,
+	.recalc = &gpt_clk_recalc,
+	.private_data = &gpt0_config,
+};
+
+/* gpt1 configurations */
+static struct aux_clk_config gpt1_config = {
+	.synth_reg = PRSC2_CLK_CFG,
+};
+
+/* gpt1 timer clock */
+static struct clk gpt1_clk = {
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = GPT1_CLK_ENB,
+	.pclk_sel = &gpt_pclk_sel,
+	.pclk_sel_shift = GPT1_CLK_SHIFT,
+	.recalc = &gpt_clk_recalc,
+	.private_data = &gpt1_config,
+};
+
+/* gpt2 configurations */
+static struct aux_clk_config gpt2_config = {
+	.synth_reg = PRSC3_CLK_CFG,
+};
+
+/* gpt2 timer clock */
+static struct clk gpt2_clk = {
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = GPT2_CLK_ENB,
+	.pclk_sel = &gpt_pclk_sel,
+	.pclk_sel_shift = GPT2_CLK_SHIFT,
+	.recalc = &gpt_clk_recalc,
+	.private_data = &gpt2_config,
+};
+
+/* clock derived from pll3 clk */
+/* usbh clock */
+static struct clk usbh_clk = {
+	.pclk = &pll3_48m_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = USBH_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* usbd clock */
+static struct clk usbd_clk = {
+	.pclk = &pll3_48m_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = USBD_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* clcd clock */
+static struct clk clcd_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &pll3_48m_clk,
+	.recalc = &follow_parent,
+};
+
+/* clock derived from ahb clk */
+/* apb configuration structure */
+static struct bus_clk_config apb_config = {
+	.reg = CORE_CLK_CFG,
+	.mask = HCLK_PCLK_RATIO_MASK,
+	.shift = HCLK_PCLK_RATIO_SHIFT,
+};
+
+/* apb clock */
+static struct clk apb_clk = {
+	.flags = ALWAYS_ENABLED,
+	.pclk = &ahb_clk,
+	.recalc = &bus_clk_recalc,
+	.private_data = &apb_config,
+};
+
+/* i2c clock */
+static struct clk i2c_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = I2C_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* dma clock */
+static struct clk dma_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = DMA_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* jpeg clock */
+static struct clk jpeg_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = JPEG_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* gmac clock */
+static struct clk gmac_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = GMAC_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* smi clock */
+static struct clk smi_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = SMI_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* c3 clock */
+static struct clk c3_clk = {
+	.pclk = &ahb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = C3_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* clock derived from apb clk */
+/* adc clock */
+static struct clk adc_clk = {
+	.pclk = &apb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = ADC_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* ssp clock */
+static struct clk ssp_clk = {
+	.pclk = &apb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = SSP_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* gpio clock */
+static struct clk gpio_clk = {
+	.pclk = &apb_clk,
+	.en_reg = PERIP1_CLK_ENB,
+	.en_reg_bit = GPIO_CLK_ENB,
+	.recalc = &follow_parent,
+};
+
+/* array of all spear 3xx clock lookups */
+static struct clk_lookup spear_clk_lookups[] = {
+	/* root clks */
+	{ .con_id = "osc_32k_clk",	.clk = &osc_32k_clk},
+	{ .con_id = "osc_24m_clk",	.clk = &osc_24m_clk},
+	/* clock derived from 32 KHz osc clk */
+	{ .dev_id = "rtc",		.clk = &rtc_clk},
+	/* clock derived from 24 MHz osc clk */
+	{ .con_id = "pll1_clk",		.clk = &pll1_clk},
+	{ .con_id = "pll3_48m_clk",	.clk = &pll3_48m_clk},
+	{ .dev_id = "wdt",		.clk = &wdt_clk},
+	/* clock derived from pll1 clk */
+	{ .con_id = "cpu_clk",		.clk = &cpu_clk},
+	{ .con_id = "ahb_clk",		.clk = &ahb_clk},
+	{ .dev_id = "uart",		.clk = &uart_clk},
+	{ .dev_id = "firda",		.clk = &firda_clk},
+	{ .dev_id = "gpt0",		.clk = &gpt0_clk},
+	{ .dev_id = "gpt1",		.clk = &gpt1_clk},
+	{ .dev_id = "gpt2",		.clk = &gpt2_clk},
+	/* clock derived from pll3 clk */
+	{ .dev_id = "usbh",		.clk = &usbh_clk},
+	{ .dev_id = "usbd",		.clk = &usbd_clk},
+	{ .dev_id = "clcd",		.clk = &clcd_clk},
+	/* clock derived from ahb clk */
+	{ .con_id = "apb_clk",		.clk = &apb_clk},
+	{ .dev_id = "i2c",		.clk = &i2c_clk},
+	{ .dev_id = "dma",		.clk = &dma_clk},
+	{ .dev_id = "jpeg",		.clk = &jpeg_clk},
+	{ .dev_id = "gmac",		.clk = &gmac_clk},
+	{ .dev_id = "smi",		.clk = &smi_clk},
+	{ .dev_id = "c3",		.clk = &c3_clk},
+	/* clock derived from apb clk */
+	{ .dev_id = "adc",		.clk = &adc_clk},
+	{ .dev_id = "ssp",		.clk = &ssp_clk},
+	{ .dev_id = "gpio",		.clk = &gpio_clk},
+};
+
+void __init clk_init(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(spear_clk_lookups); i++)
+		clk_register(&spear_clk_lookups[i]);
+
+	recalc_root_clocks();
+}

arch/arm/mach-spear3xx/include/mach/clkdev.h

+/*
+ * arch/arm/mach-spear3xx/include/mach/clkdev.h
+ *
+ * Clock Dev framework definitions for SPEAr3xx machine family
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.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.
+ */
+
+#ifndef __MACH_CLKDEV_H
+#define __MACH_CLKDEV_H
+
+#include <plat/clkdev.h>
+
+#endif /* __MACH_CLKDEV_H */

arch/arm/mach-spear6xx/include/mach/clkdev.h

+/*
+ * arch/arm/mach-spear6xx/include/mach/clkdev.h
+ *
+ * Clock Dev framework definitions for SPEAr6xx machine family
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.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.
+ */
+
+#ifndef __MACH_CLKDEV_H
+#define __MACH_CLKDEV_H
+
+#include <plat/clkdev.h>
+
+#endif /* __MACH_CLKDEV_H */

arch/arm/plat-spear/include/plat/clkdev.h

+/*
+ * arch/arm/plat-spear/include/plat/clkdev.h
+ *
+ * Clock Dev framework definitions for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.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.
+ */
+
+#ifndef __PLAT_CLKDEV_H
+#define __PLAT_CLKDEV_H
+
+#define __clk_get(clk) ({ 1; })
+#define __clk_put(clk) do { } while (0)
+
+#endif /* __PLAT_CLKDEV_H */

arch/arm/plat-spear/include/plat/clock.h

+/*
+ * arch/arm/plat-spear/include/plat/clock.h
+ *
+ * Clock framework definitions for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.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.
+ */
+
+#ifndef __PLAT_CLOCK_H
+#define __PLAT_CLOCK_H
+
+#include <linux/list.h>
+#include <asm/clkdev.h>
+#include <linux/types.h>
+
+/* clk structure flags */
+#define	ALWAYS_ENABLED		(1 << 0) /* clock always enabled */
+#define	RESET_TO_ENABLE		(1 << 1) /* reset register bit to enable clk */
+
+/**
+ * struct clkops - clock operations
+ * @enable: pointer to clock enable function
+ * @disable: pointer to clock disable function
+ */
+struct clkops {
+	int (*enable) (struct clk *);
+	void (*disable) (struct clk *);
+};
+
+/**
+ * struct pclk_info - parents info
+ * @pclk: pointer to parent clk
+ * @pclk_mask: value to be written for selecting this parent
+ * @scalable: Is parent scalable (1 - YES, 0 - NO)
+ */
+struct pclk_info {
+	struct clk *pclk;
+	u8 pclk_mask;
+	u8 scalable;
+};
+
+/**
+ * struct pclk_sel - parents selection configuration
+ * @pclk_info: pointer to array of parent clock info
+ * @pclk_count: number of parents
+ * @pclk_sel_reg: register for selecting a parent
+ * @pclk_sel_mask: mask for selecting parent (can be used to clear bits also)
+ */
+struct pclk_sel {
+	struct pclk_info *pclk_info;
+	u8 pclk_count;
+	unsigned int *pclk_sel_reg;
+	unsigned int pclk_sel_mask;
+};
+
+/**
+ * struct clk - clock structure
+ * @usage_count: num of users who enabled this clock
+ * @flags: flags for clock properties
+ * @rate: programmed clock rate in Hz
+ * @en_reg: clk enable/disable reg
+ * @en_reg_bit: clk enable/disable bit
+ * @ops: clk enable/disable ops - generic_clkops selected if NULL
+ * @recalc: pointer to clock rate recalculate function
+ * @pclk: current parent clk
+ * @pclk_sel: pointer to parent selection structure
+ * @pclk_sel_shift: register shift for selecting parent of this clock
+ * @children: list for childrens or this clock
+ * @sibling: node for list of clocks having same parents
+ * @private_data: clock specific private data
+ */
+struct clk {
+	unsigned int usage_count;
+	unsigned int flags;
+	unsigned long rate;
+	unsigned int *en_reg;
+	u8 en_reg_bit;
+	const struct clkops *ops;
+	void (*recalc) (struct clk *);
+
+	struct clk *pclk;
+	struct pclk_sel *pclk_sel;
+	unsigned int pclk_sel_shift;
+
+	struct list_head children;
+	struct list_head sibling;
+	void *private_data;
+};
+
+/* pll configuration structure */
+struct pll_clk_config {
+	unsigned int *mode_reg;
+	unsigned int *cfg_reg;
+};
+
+/* ahb and apb bus configuration structure */
+struct bus_clk_config {
+	unsigned int *reg;
+	unsigned int mask;
+	unsigned int shift;
+};
+
+/*
+ * Aux clk configuration structure: applicable to GPT, UART and FIRDA
+ */
+struct aux_clk_config {
+	unsigned int *synth_reg;
+};
+
+/* platform specific clock functions */
+void clk_register(struct clk_lookup *cl);
+void recalc_root_clocks(void);
+
+/* clock recalc functions */
+void follow_parent(struct clk *clk);
+void pll1_clk_recalc(struct clk *clk);
+void bus_clk_recalc(struct clk *clk);
+void gpt_clk_recalc(struct clk *clk);
+void aux_clk_recalc(struct clk *clk);
+
+#endif /* __PLAT_CLOCK_H */