diff options
Diffstat (limited to 'drivers/clk/rockchip/clk-inverter.c')
-rw-r--r-- | drivers/clk/rockchip/clk-inverter.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-inverter.c b/drivers/clk/rockchip/clk-inverter.c new file mode 100644 index 000000000..dcb6e37f3 --- /dev/null +++ b/drivers/clk/rockchip/clk-inverter.c @@ -0,0 +1,112 @@ +/* + * 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 ERR_PTR(-ENOMEM); + + 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)) + kfree(inv_clock); + + return clk; +} |