diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/mmp/clk-gate.c | 127 |
1 files changed, 127 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..350eeb3e9 --- /dev/null +++ b/drivers/clk/mmp/clk-gate.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * mmp gate clock operation source file + * + * Copyright (C) 2014 Marvell + * Chao Xie <chao.xie@marvell.com> + */ + +#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); + 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_hw_get_rate(hw); + /* 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) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &mmp_clk_gate_ops; + init.flags = flags; + 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; +} |