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-rw-r--r--drivers/clk/imx/clk-divider-gate.c221
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-divider-gate.c b/drivers/clk/imx/clk-divider-gate.c
new file mode 100644
index 000000000..26b210cba
--- /dev/null
+++ b/drivers/clk/imx/clk-divider-gate.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP.
+ * Dong Aisheng <aisheng.dong@nxp.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+struct clk_divider_gate {
+ struct clk_divider divider;
+ u32 cached_val;
+};
+
+static inline struct clk_divider_gate *to_clk_divider_gate(struct clk_hw *hw)
+{
+ struct clk_divider *div = to_clk_divider(hw);
+
+ return container_of(div, struct clk_divider_gate, divider);
+}
+
+static unsigned long clk_divider_gate_recalc_rate_ro(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_divider *div = to_clk_divider(hw);
+ unsigned int val;
+
+ val = readl(div->reg) >> div->shift;
+ val &= clk_div_mask(div->width);
+ if (!val)
+ return 0;
+
+ return divider_recalc_rate(hw, parent_rate, val, div->table,
+ div->flags, div->width);
+}
+
+static unsigned long clk_divider_gate_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
+ struct clk_divider *div = to_clk_divider(hw);
+ unsigned long flags;
+ unsigned int val;
+
+ spin_lock_irqsave(div->lock, flags);
+
+ if (!clk_hw_is_enabled(hw)) {
+ val = div_gate->cached_val;
+ } else {
+ val = readl(div->reg) >> div->shift;
+ val &= clk_div_mask(div->width);
+ }
+
+ spin_unlock_irqrestore(div->lock, flags);
+
+ if (!val)
+ return 0;
+
+ return divider_recalc_rate(hw, parent_rate, val, div->table,
+ div->flags, div->width);
+}
+
+static int clk_divider_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ return clk_divider_ops.determine_rate(hw, req);
+}
+
+static int clk_divider_gate_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
+ struct clk_divider *div = to_clk_divider(hw);
+ unsigned long flags;
+ int value;
+ u32 val;
+
+ value = divider_get_val(rate, parent_rate, div->table,
+ div->width, div->flags);
+ if (value < 0)
+ return value;
+
+ spin_lock_irqsave(div->lock, flags);
+
+ if (clk_hw_is_enabled(hw)) {
+ val = readl(div->reg);
+ val &= ~(clk_div_mask(div->width) << div->shift);
+ val |= (u32)value << div->shift;
+ writel(val, div->reg);
+ } else {
+ div_gate->cached_val = value;
+ }
+
+ spin_unlock_irqrestore(div->lock, flags);
+
+ return 0;
+}
+
+static int clk_divider_enable(struct clk_hw *hw)
+{
+ struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
+ struct clk_divider *div = to_clk_divider(hw);
+ unsigned long flags;
+ u32 val;
+
+ if (!div_gate->cached_val) {
+ pr_err("%s: no valid preset rate\n", clk_hw_get_name(hw));
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(div->lock, flags);
+ /* restore div val */
+ val = readl(div->reg);
+ val |= div_gate->cached_val << div->shift;
+ writel(val, div->reg);
+
+ spin_unlock_irqrestore(div->lock, flags);
+
+ return 0;
+}
+
+static void clk_divider_disable(struct clk_hw *hw)
+{
+ struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
+ struct clk_divider *div = to_clk_divider(hw);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(div->lock, flags);
+
+ /* store the current div val */
+ val = readl(div->reg) >> div->shift;
+ val &= clk_div_mask(div->width);
+ div_gate->cached_val = val;
+ writel(0, div->reg);
+
+ spin_unlock_irqrestore(div->lock, flags);
+}
+
+static int clk_divider_is_enabled(struct clk_hw *hw)
+{
+ struct clk_divider *div = to_clk_divider(hw);
+ u32 val;
+
+ val = readl(div->reg) >> div->shift;
+ val &= clk_div_mask(div->width);
+
+ return val ? 1 : 0;
+}
+
+static const struct clk_ops clk_divider_gate_ro_ops = {
+ .recalc_rate = clk_divider_gate_recalc_rate_ro,
+ .determine_rate = clk_divider_determine_rate,
+};
+
+static const struct clk_ops clk_divider_gate_ops = {
+ .recalc_rate = clk_divider_gate_recalc_rate,
+ .determine_rate = clk_divider_determine_rate,
+ .set_rate = clk_divider_gate_set_rate,
+ .enable = clk_divider_enable,
+ .disable = clk_divider_disable,
+ .is_enabled = clk_divider_is_enabled,
+};
+
+/*
+ * NOTE: In order to reuse the most code from the common divider,
+ * we also design our divider following the way that provids an extra
+ * clk_divider_flags, however it's fixed to CLK_DIVIDER_ONE_BASED by
+ * default as our HW is. Besides that it supports only CLK_DIVIDER_READ_ONLY
+ * flag which can be specified by user flexibly.
+ */
+struct clk_hw *imx_clk_hw_divider_gate(const char *name, const char *parent_name,
+ unsigned long flags, void __iomem *reg,
+ u8 shift, u8 width, u8 clk_divider_flags,
+ const struct clk_div_table *table,
+ spinlock_t *lock)
+{
+ struct clk_init_data init;
+ struct clk_divider_gate *div_gate;
+ struct clk_hw *hw;
+ u32 val;
+ int ret;
+
+ div_gate = kzalloc(sizeof(*div_gate), GFP_KERNEL);
+ if (!div_gate)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ if (clk_divider_flags & CLK_DIVIDER_READ_ONLY)
+ init.ops = &clk_divider_gate_ro_ops;
+ else
+ init.ops = &clk_divider_gate_ops;
+ init.flags = flags;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+
+ div_gate->divider.reg = reg;
+ div_gate->divider.shift = shift;
+ div_gate->divider.width = width;
+ div_gate->divider.lock = lock;
+ div_gate->divider.table = table;
+ div_gate->divider.hw.init = &init;
+ div_gate->divider.flags = CLK_DIVIDER_ONE_BASED | clk_divider_flags;
+ /* cache gate status */
+ val = readl(reg) >> shift;
+ val &= clk_div_mask(width);
+ div_gate->cached_val = val;
+
+ hw = &div_gate->divider.hw;
+ ret = clk_hw_register(NULL, hw);
+ if (ret) {
+ kfree(div_gate);
+ hw = ERR_PTR(ret);
+ }
+
+ return hw;
+}