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>

1 files changed, 126 insertions, 0 deletions

diff --git a/arch/arm/plat-spear/include/plat/clock.h b/arch/arm/plat-spear/include/plat/clock.h
new file mode 100644
index 00000000000..298bafc0a52
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/clock.h
@@ -0,0 +1,126 @@
+/*
+ * 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 */