diff options
Diffstat (limited to 'drivers/clk/zte/clk-pll.c')
| -rw-r--r-- | drivers/clk/zte/clk-pll.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/clk/zte/clk-pll.c b/drivers/clk/zte/clk-pll.c new file mode 100644 index 000000000000..c3b221ae6cd7 --- /dev/null +++ b/drivers/clk/zte/clk-pll.c @@ -0,0 +1,172 @@ +/* + * Copyright 2014 Linaro Ltd. + * Copyright (C) 2014 ZTE Corporation. + * + * 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/clk-provider.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "clk.h" + +#define to_clk_zx_pll(_hw) container_of(_hw, struct clk_zx_pll, hw) + +#define CFG0_CFG1_OFFSET 4 +#define LOCK_FLAG BIT(30) +#define POWER_DOWN BIT(31) + +static int rate_to_idx(struct clk_zx_pll *zx_pll, unsigned long rate) +{ + const struct zx_pll_config *config = zx_pll->lookup_table; + int i; + + for (i = 0; i < zx_pll->count; i++) { + if (config[i].rate > rate) + return i > 0 ? i - 1 : 0; + + if (config[i].rate == rate) + return i; + } + + return i - 1; +} + +static int hw_to_idx(struct clk_zx_pll *zx_pll) +{ + const struct zx_pll_config *config = zx_pll->lookup_table; + u32 hw_cfg0, hw_cfg1; + int i; + + hw_cfg0 = readl_relaxed(zx_pll->reg_base); + hw_cfg1 = readl_relaxed(zx_pll->reg_base + CFG0_CFG1_OFFSET); + + /* For matching the value in lookup table */ + hw_cfg0 &= ~LOCK_FLAG; + hw_cfg0 |= POWER_DOWN; + + for (i = 0; i < zx_pll->count; i++) { + if (hw_cfg0 == config[i].cfg0 && hw_cfg1 == config[i].cfg1) + return i; + } + + return -EINVAL; +} + +static unsigned long zx_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + int idx; + + idx = hw_to_idx(zx_pll); + if (unlikely(idx == -EINVAL)) + return 0; + + return zx_pll->lookup_table[idx].rate; +} + +static long zx_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + int idx; + + idx = rate_to_idx(zx_pll, rate); + + return zx_pll->lookup_table[idx].rate; +} + +static int zx_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + /* Assume current cpu is not running on current PLL */ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + const struct zx_pll_config *config; + int idx; + + idx = rate_to_idx(zx_pll, rate); + config = &zx_pll->lookup_table[idx]; + + writel_relaxed(config->cfg0, zx_pll->reg_base); + writel_relaxed(config->cfg1, zx_pll->reg_base + CFG0_CFG1_OFFSET); + + return 0; +} + +static int zx_pll_enable(struct clk_hw *hw) +{ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + u32 reg; + + reg = readl_relaxed(zx_pll->reg_base); + writel_relaxed(reg & ~POWER_DOWN, zx_pll->reg_base); + + return readl_relaxed_poll_timeout(zx_pll->reg_base, reg, + reg & LOCK_FLAG, 0, 100); +} + +static void zx_pll_disable(struct clk_hw *hw) +{ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + u32 reg; + + reg = readl_relaxed(zx_pll->reg_base); + writel_relaxed(reg | POWER_DOWN, zx_pll->reg_base); +} + +static int zx_pll_is_enabled(struct clk_hw *hw) +{ + struct clk_zx_pll *zx_pll = to_clk_zx_pll(hw); + u32 reg; + + reg = readl_relaxed(zx_pll->reg_base); + + return !(reg & POWER_DOWN); +} + +static const struct clk_ops zx_pll_ops = { + .recalc_rate = zx_pll_recalc_rate, + .round_rate = zx_pll_round_rate, + .set_rate = zx_pll_set_rate, + .enable = zx_pll_enable, + .disable = zx_pll_disable, + .is_enabled = zx_pll_is_enabled, +}; + +struct clk *clk_register_zx_pll(const char *name, const char *parent_name, + unsigned long flags, void __iomem *reg_base, + const struct zx_pll_config *lookup_table, int count, spinlock_t *lock) +{ + struct clk_zx_pll *zx_pll; + struct clk *clk; + struct clk_init_data init; + + zx_pll = kzalloc(sizeof(*zx_pll), GFP_KERNEL); + if (!zx_pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &zx_pll_ops; + init.flags = flags; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + + zx_pll->reg_base = reg_base; + zx_pll->lookup_table = lookup_table; + zx_pll->count = count; + zx_pll->lock = lock; + zx_pll->hw.init = &init; + + clk = clk_register(NULL, &zx_pll->hw); + if (IS_ERR(clk)) + kfree(zx_pll); + + return clk; +} |