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path: root/drivers/clk/hisilicon/clkdivider-hi6220.c
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Diffstat (limited to 'drivers/clk/hisilicon/clkdivider-hi6220.c')
-rw-r--r--drivers/clk/hisilicon/clkdivider-hi6220.c156
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/clkdivider-hi6220.c b/drivers/clk/hisilicon/clkdivider-hi6220.c
new file mode 100644
index 000000000000..113eee8ed23a
--- /dev/null
+++ b/drivers/clk/hisilicon/clkdivider-hi6220.c
@@ -0,0 +1,156 @@
+/*
+ * Hisilicon hi6220 SoC divider clock driver
+ *
+ * Copyright (c) 2015 Hisilicon Limited.
+ *
+ * Author: Bintian Wang <bintian.wang@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+
+#define div_mask(width) ((1 << (width)) - 1)
+
+/**
+ * struct hi6220_clk_divider - divider clock for hi6220
+ *
+ * @hw: handle between common and hardware-specific interfaces
+ * @reg: register containing divider
+ * @shift: shift to the divider bit field
+ * @width: width of the divider bit field
+ * @mask: mask for setting divider rate
+ * @table: the div table that the divider supports
+ * @lock: register lock
+ */
+struct hi6220_clk_divider {
+ struct clk_hw hw;
+ void __iomem *reg;
+ u8 shift;
+ u8 width;
+ u32 mask;
+ const struct clk_div_table *table;
+ spinlock_t *lock;
+};
+
+#define to_hi6220_clk_divider(_hw) \
+ container_of(_hw, struct hi6220_clk_divider, hw)
+
+static unsigned long hi6220_clkdiv_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ unsigned int val;
+ struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
+
+ val = readl_relaxed(dclk->reg) >> dclk->shift;
+ val &= div_mask(dclk->width);
+
+ return divider_recalc_rate(hw, parent_rate, val, dclk->table,
+ CLK_DIVIDER_ROUND_CLOSEST);
+}
+
+static long hi6220_clkdiv_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
+
+ return divider_round_rate(hw, rate, prate, dclk->table,
+ dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
+}
+
+static int hi6220_clkdiv_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ int value;
+ unsigned long flags = 0;
+ u32 data;
+ struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
+
+ value = divider_get_val(rate, parent_rate, dclk->table,
+ dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
+
+ if (dclk->lock)
+ spin_lock_irqsave(dclk->lock, flags);
+
+ data = readl_relaxed(dclk->reg);
+ data &= ~(div_mask(dclk->width) << dclk->shift);
+ data |= value << dclk->shift;
+ data |= dclk->mask;
+
+ writel_relaxed(data, dclk->reg);
+
+ if (dclk->lock)
+ spin_unlock_irqrestore(dclk->lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops hi6220_clkdiv_ops = {
+ .recalc_rate = hi6220_clkdiv_recalc_rate,
+ .round_rate = hi6220_clkdiv_round_rate,
+ .set_rate = hi6220_clkdiv_set_rate,
+};
+
+struct clk *hi6220_register_clkdiv(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags, void __iomem *reg,
+ u8 shift, u8 width, u32 mask_bit, spinlock_t *lock)
+{
+ struct hi6220_clk_divider *div;
+ struct clk *clk;
+ struct clk_init_data init;
+ struct clk_div_table *table;
+ u32 max_div, min_div;
+ int i;
+
+ /* allocate the divider */
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOMEM);
+
+ /* Init the divider table */
+ max_div = div_mask(width) + 1;
+ min_div = 1;
+
+ table = kcalloc(max_div + 1, sizeof(*table), GFP_KERNEL);
+ if (!table) {
+ kfree(div);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for (i = 0; i < max_div; i++) {
+ table[i].div = min_div + i;
+ table[i].val = table[i].div - 1;
+ }
+
+ init.name = name;
+ init.ops = &hi6220_clkdiv_ops;
+ init.flags = flags;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+
+ /* struct hi6220_clk_divider assignments */
+ div->reg = reg;
+ div->shift = shift;
+ div->width = width;
+ div->mask = mask_bit ? BIT(mask_bit) : 0;
+ div->lock = lock;
+ div->hw.init = &init;
+ div->table = table;
+
+ /* register the clock */
+ clk = clk_register(dev, &div->hw);
+ if (IS_ERR(clk)) {
+ kfree(table);
+ kfree(div);
+ }
+
+ return clk;
+}