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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/clk/mmp/clk-gate.c
Initial import
Diffstat (limited to 'drivers/clk/mmp/clk-gate.c')
-rw-r--r--drivers/clk/mmp/clk-gate.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/clk/mmp/clk-gate.c b/drivers/clk/mmp/clk-gate.c
new file mode 100644
index 000000000..adbd9d64d
--- /dev/null
+++ b/drivers/clk/mmp/clk-gate.c
@@ -0,0 +1,133 @@
+/*
+ * mmp gate clock operation source file
+ *
+ * Copyright (C) 2014 Marvell
+ * Chao Xie <chao.xie@marvell.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/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+
+#include "clk.h"
+
+/*
+ * Some clocks will have mutiple bits to enable the clocks, and
+ * the bits to disable the clock is not same as enabling bits.
+ */
+
+#define to_clk_mmp_gate(hw) container_of(hw, struct mmp_clk_gate, hw)
+
+static int mmp_clk_gate_enable(struct clk_hw *hw)
+{
+ struct mmp_clk_gate *gate = to_clk_mmp_gate(hw);
+ struct clk *clk = hw->clk;
+ unsigned long flags = 0;
+ unsigned long rate;
+ u32 tmp;
+
+ if (gate->lock)
+ spin_lock_irqsave(gate->lock, flags);
+
+ tmp = readl(gate->reg);
+ tmp &= ~gate->mask;
+ tmp |= gate->val_enable;
+ writel(tmp, gate->reg);
+
+ if (gate->lock)
+ spin_unlock_irqrestore(gate->lock, flags);
+
+ if (gate->flags & MMP_CLK_GATE_NEED_DELAY) {
+ rate = __clk_get_rate(clk);
+ /* Need delay 2 cycles. */
+ udelay(2000000/rate);
+ }
+
+ return 0;
+}
+
+static void mmp_clk_gate_disable(struct clk_hw *hw)
+{
+ struct mmp_clk_gate *gate = to_clk_mmp_gate(hw);
+ unsigned long flags = 0;
+ u32 tmp;
+
+ if (gate->lock)
+ spin_lock_irqsave(gate->lock, flags);
+
+ tmp = readl(gate->reg);
+ tmp &= ~gate->mask;
+ tmp |= gate->val_disable;
+ writel(tmp, gate->reg);
+
+ if (gate->lock)
+ spin_unlock_irqrestore(gate->lock, flags);
+}
+
+static int mmp_clk_gate_is_enabled(struct clk_hw *hw)
+{
+ struct mmp_clk_gate *gate = to_clk_mmp_gate(hw);
+ unsigned long flags = 0;
+ u32 tmp;
+
+ if (gate->lock)
+ spin_lock_irqsave(gate->lock, flags);
+
+ tmp = readl(gate->reg);
+
+ if (gate->lock)
+ spin_unlock_irqrestore(gate->lock, flags);
+
+ return (tmp & gate->mask) == gate->val_enable;
+}
+
+const struct clk_ops mmp_clk_gate_ops = {
+ .enable = mmp_clk_gate_enable,
+ .disable = mmp_clk_gate_disable,
+ .is_enabled = mmp_clk_gate_is_enabled,
+};
+
+struct clk *mmp_clk_register_gate(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u32 mask, u32 val_enable, u32 val_disable,
+ unsigned int gate_flags, spinlock_t *lock)
+{
+ struct mmp_clk_gate *gate;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ /* allocate the gate */
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate) {
+ pr_err("%s:%s could not allocate gate clk\n", __func__, name);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &mmp_clk_gate_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+
+ /* struct clk_gate assignments */
+ gate->reg = reg;
+ gate->mask = mask;
+ gate->val_enable = val_enable;
+ gate->val_disable = val_disable;
+ gate->flags = gate_flags;
+ gate->lock = lock;
+ gate->hw.init = &init;
+
+ clk = clk_register(dev, &gate->hw);
+
+ if (IS_ERR(clk))
+ kfree(gate);
+
+ return clk;
+}