[ARM] msm: clock: provide clk_*() api support for

Makes use of the proc_comm interface to provide clock control on
MSM7X01A family SoCs.

Signed-off-by: Brian Swetland <swetland@google.com>

1 files changed, 218 insertions, 0 deletions

diff --git a/arch/arm/mach-msm/clock.c b/arch/arm/mach-msm/clock.c
new file mode 100644
index 000000000000..3b1ce36f1032
--- /dev/null
+++ b/arch/arm/mach-msm/clock.c
@@ -0,0 +1,218 @@
+/* arch/arm/mach-msm/clock.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2007 QUALCOMM Incorporated
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+
+#include "clock.h"
+#include "proc_comm.h"
+
+static DEFINE_MUTEX(clocks_mutex);
+static DEFINE_SPINLOCK(clocks_lock);
+static LIST_HEAD(clocks);
+
+/*
+ * glue for the proc_comm interface
+ */
+static inline int pc_clk_enable(unsigned id)
+{
+	return msm_proc_comm(PCOM_CLKCTL_RPC_ENABLE, &id, NULL);
+}
+
+static inline void pc_clk_disable(unsigned id)
+{
+	msm_proc_comm(PCOM_CLKCTL_RPC_DISABLE, &id, NULL);
+}
+
+static inline int pc_clk_set_rate(unsigned id, unsigned rate)
+{
+	return msm_proc_comm(PCOM_CLKCTL_RPC_SET_RATE, &id, &rate);
+}
+
+static inline int pc_clk_set_min_rate(unsigned id, unsigned rate)
+{
+	return msm_proc_comm(PCOM_CLKCTL_RPC_MIN_RATE, &id, &rate);
+}
+
+static inline int pc_clk_set_max_rate(unsigned id, unsigned rate)
+{
+	return msm_proc_comm(PCOM_CLKCTL_RPC_MAX_RATE, &id, &rate);
+}
+
+static inline int pc_clk_set_flags(unsigned id, unsigned flags)
+{
+	return msm_proc_comm(PCOM_CLKCTL_RPC_SET_FLAGS, &id, &flags);
+}
+
+static inline unsigned pc_clk_get_rate(unsigned id)
+{
+	if (msm_proc_comm(PCOM_CLKCTL_RPC_RATE, &id, NULL))
+		return 0;
+	else
+		return id;
+}
+
+static inline unsigned pc_clk_is_enabled(unsigned id)
+{
+	if (msm_proc_comm(PCOM_CLKCTL_RPC_ENABLED, &id, NULL))
+		return 0;
+	else
+		return id;
+}
+
+static inline int pc_pll_request(unsigned id, unsigned on)
+{
+	on = !!on;
+	return msm_proc_comm(PCOM_CLKCTL_RPC_PLL_REQUEST, &id, &on);
+}
+
+/*
+ * Standard clock functions defined in include/linux/clk.h
+ */
+struct clk *clk_get(struct device *dev, const char *id)
+{
+	struct clk *clk;
+
+	mutex_lock(&clocks_mutex);
+
+	list_for_each_entry(clk, &clocks, list)
+		if (!strcmp(id, clk->name) && clk->dev == dev)
+			goto found_it;
+
+	list_for_each_entry(clk, &clocks, list)
+		if (!strcmp(id, clk->name) && clk->dev == NULL)
+			goto found_it;
+
+	clk = ERR_PTR(-ENOENT);
+found_it:
+	mutex_unlock(&clocks_mutex);
+	return clk;
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(clk_put);
+
+int clk_enable(struct clk *clk)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&clocks_lock, flags);
+	clk->count++;
+	if (clk->count == 1)
+		pc_clk_enable(clk->id);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&clocks_lock, flags);
+	BUG_ON(clk->count == 0);
+	clk->count--;
+	if (clk->count == 0)
+		pc_clk_disable(clk->id);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	return pc_clk_get_rate(clk->id);
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	int ret;
+	if (clk->flags & CLKFLAG_USE_MIN_MAX_TO_SET) {
+		ret = pc_clk_set_max_rate(clk->id, rate);
+		if (ret)
+			return ret;
+		return pc_clk_set_min_rate(clk->id, rate);
+	}
+	return pc_clk_set_rate(clk->id, rate);
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+	return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL(clk_get_parent);
+
+int clk_set_flags(struct clk *clk, unsigned long flags)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+	return pc_clk_set_flags(clk->id, flags);
+}
+EXPORT_SYMBOL(clk_set_flags);
+
+
+void __init msm_clock_init(void)
+{
+	unsigned n;
+
+	spin_lock_init(&clocks_lock);
+	mutex_lock(&clocks_mutex);
+	for (n = 0; n < msm_num_clocks; n++)
+		list_add_tail(&msm_clocks[n].list, &clocks);
+	mutex_unlock(&clocks_mutex);
+}
+
+/* The bootloader and/or AMSS may have left various clocks enabled.
+ * Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
+ * not been explicitly enabled by a clk_enable() call.
+ */
+static int __init clock_late_init(void)
+{
+	unsigned long flags;
+	struct clk *clk;
+	unsigned count = 0;
+
+	mutex_lock(&clocks_mutex);
+	list_for_each_entry(clk, &clocks, list) {
+		if (clk->flags & CLKFLAG_AUTO_OFF) {
+			spin_lock_irqsave(&clocks_lock, flags);
+			if (!clk->count) {
+				count++;
+				pc_clk_disable(clk->id);
+			}
+			spin_unlock_irqrestore(&clocks_lock, flags);
+		}
+	}
+	mutex_unlock(&clocks_mutex);
+	pr_info("clock_late_init() disabled %d unused clocks\n", count);
+	return 0;
+}
+
+late_initcall(clock_late_init);