summaryrefslogtreecommitdiff
path: root/drivers/clk/mmp/clk-apbc.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/mmp/clk-apbc.c')
-rw-r--r--drivers/clk/mmp/clk-apbc.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/clk/mmp/clk-apbc.c b/drivers/clk/mmp/clk-apbc.c
new file mode 100644
index 000000000000..d14120eaa71f
--- /dev/null
+++ b/drivers/clk/mmp/clk-apbc.c
@@ -0,0 +1,152 @@
+/*
+ * mmp APB clock operation source file
+ *
+ * Copyright (C) 2012 Marvell
+ * Chao Xie <xiechao.mail@gmail.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/kernel.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+/* Common APB clock register bit definitions */
+#define APBC_APBCLK (1 << 0) /* APB Bus Clock Enable */
+#define APBC_FNCLK (1 << 1) /* Functional Clock Enable */
+#define APBC_RST (1 << 2) /* Reset Generation */
+#define APBC_POWER (1 << 7) /* Reset Generation */
+
+#define to_clk_apbc(hw) container_of(hw, struct clk_apbc, hw)
+struct clk_apbc {
+ struct clk_hw hw;
+ void __iomem *base;
+ unsigned int delay;
+ unsigned int flags;
+ spinlock_t *lock;
+};
+
+static int clk_apbc_prepare(struct clk_hw *hw)
+{
+ struct clk_apbc *apbc = to_clk_apbc(hw);
+ unsigned int data;
+ unsigned long flags = 0;
+
+ /*
+ * It may share same register as MUX clock,
+ * and it will impact FNCLK enable. Spinlock is needed
+ */
+ if (apbc->lock)
+ spin_lock_irqsave(apbc->lock, flags);
+
+ data = readl_relaxed(apbc->base);
+ if (apbc->flags & APBC_POWER_CTRL)
+ data |= APBC_POWER;
+ data |= APBC_FNCLK;
+ writel_relaxed(data, apbc->base);
+
+ if (apbc->lock)
+ spin_unlock_irqrestore(apbc->lock, flags);
+
+ udelay(apbc->delay);
+
+ if (apbc->lock)
+ spin_lock_irqsave(apbc->lock, flags);
+
+ data = readl_relaxed(apbc->base);
+ data |= APBC_APBCLK;
+ writel_relaxed(data, apbc->base);
+
+ if (apbc->lock)
+ spin_unlock_irqrestore(apbc->lock, flags);
+
+ udelay(apbc->delay);
+
+ if (!(apbc->flags & APBC_NO_BUS_CTRL)) {
+ if (apbc->lock)
+ spin_lock_irqsave(apbc->lock, flags);
+
+ data = readl_relaxed(apbc->base);
+ data &= ~APBC_RST;
+ writel_relaxed(data, apbc->base);
+
+ if (apbc->lock)
+ spin_unlock_irqrestore(apbc->lock, flags);
+ }
+
+ return 0;
+}
+
+static void clk_apbc_unprepare(struct clk_hw *hw)
+{
+ struct clk_apbc *apbc = to_clk_apbc(hw);
+ unsigned long data;
+ unsigned long flags = 0;
+
+ if (apbc->lock)
+ spin_lock_irqsave(apbc->lock, flags);
+
+ data = readl_relaxed(apbc->base);
+ if (apbc->flags & APBC_POWER_CTRL)
+ data &= ~APBC_POWER;
+ data &= ~APBC_FNCLK;
+ writel_relaxed(data, apbc->base);
+
+ if (apbc->lock)
+ spin_unlock_irqrestore(apbc->lock, flags);
+
+ udelay(10);
+
+ if (apbc->lock)
+ spin_lock_irqsave(apbc->lock, flags);
+
+ data = readl_relaxed(apbc->base);
+ data &= ~APBC_APBCLK;
+ writel_relaxed(data, apbc->base);
+
+ if (apbc->lock)
+ spin_unlock_irqrestore(apbc->lock, flags);
+}
+
+struct clk_ops clk_apbc_ops = {
+ .prepare = clk_apbc_prepare,
+ .unprepare = clk_apbc_unprepare,
+};
+
+struct clk *mmp_clk_register_apbc(const char *name, const char *parent_name,
+ void __iomem *base, unsigned int delay,
+ unsigned int apbc_flags, spinlock_t *lock)
+{
+ struct clk_apbc *apbc;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ apbc = kzalloc(sizeof(*apbc), GFP_KERNEL);
+ if (!apbc)
+ return NULL;
+
+ init.name = name;
+ init.ops = &clk_apbc_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+
+ apbc->base = base;
+ apbc->delay = delay;
+ apbc->flags = apbc_flags;
+ apbc->lock = lock;
+ apbc->hw.init = &init;
+
+ clk = clk_register(NULL, &apbc->hw);
+ if (IS_ERR(clk))
+ kfree(apbc);
+
+ return clk;
+}