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path: root/drivers/clk/rockchip/clk-inverter.c
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Diffstat (limited to 'drivers/clk/rockchip/clk-inverter.c')
-rw-r--r--drivers/clk/rockchip/clk-inverter.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-inverter.c b/drivers/clk/rockchip/clk-inverter.c
new file mode 100644
index 000000000000..7cbf43beb3c6
--- /dev/null
+++ b/drivers/clk/rockchip/clk-inverter.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2015 Heiko Stuebner <heiko@sntech.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/slab.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include "clk.h"
+
+struct rockchip_inv_clock {
+ struct clk_hw hw;
+ void __iomem *reg;
+ int shift;
+ int flags;
+ spinlock_t *lock;
+};
+
+#define to_inv_clock(_hw) container_of(_hw, struct rockchip_inv_clock, hw)
+
+#define INVERTER_MASK 0x1
+
+static int rockchip_inv_get_phase(struct clk_hw *hw)
+{
+ struct rockchip_inv_clock *inv_clock = to_inv_clock(hw);
+ u32 val;
+
+ val = readl(inv_clock->reg) >> inv_clock->shift;
+ val &= INVERTER_MASK;
+ return val ? 180 : 0;
+}
+
+static int rockchip_inv_set_phase(struct clk_hw *hw, int degrees)
+{
+ struct rockchip_inv_clock *inv_clock = to_inv_clock(hw);
+ u32 val;
+
+ if (degrees % 180 == 0) {
+ val = !!degrees;
+ } else {
+ pr_err("%s: unsupported phase %d for %s\n",
+ __func__, degrees, clk_hw_get_name(hw));
+ return -EINVAL;
+ }
+
+ if (inv_clock->flags & ROCKCHIP_INVERTER_HIWORD_MASK) {
+ writel(HIWORD_UPDATE(val, INVERTER_MASK, inv_clock->shift),
+ inv_clock->reg);
+ } else {
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(inv_clock->lock, flags);
+
+ reg = readl(inv_clock->reg);
+ reg &= ~BIT(inv_clock->shift);
+ reg |= val;
+ writel(reg, inv_clock->reg);
+
+ spin_unlock_irqrestore(inv_clock->lock, flags);
+ }
+
+ return 0;
+}
+
+static const struct clk_ops rockchip_inv_clk_ops = {
+ .get_phase = rockchip_inv_get_phase,
+ .set_phase = rockchip_inv_set_phase,
+};
+
+struct clk *rockchip_clk_register_inverter(const char *name,
+ const char *const *parent_names, u8 num_parents,
+ void __iomem *reg, int shift, int flags,
+ spinlock_t *lock)
+{
+ struct clk_init_data init;
+ struct rockchip_inv_clock *inv_clock;
+ struct clk *clk;
+
+ inv_clock = kmalloc(sizeof(*inv_clock), GFP_KERNEL);
+ if (!inv_clock)
+ return NULL;
+
+ init.name = name;
+ init.num_parents = num_parents;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = parent_names;
+ init.ops = &rockchip_inv_clk_ops;
+
+ inv_clock->hw.init = &init;
+ inv_clock->reg = reg;
+ inv_clock->shift = shift;
+ inv_clock->flags = flags;
+ inv_clock->lock = lock;
+
+ clk = clk_register(NULL, &inv_clock->hw);
+ if (IS_ERR(clk))
+ goto err_free;
+
+ return clk;
+
+err_free:
+ kfree(inv_clock);
+ return NULL;
+}