diff options
Diffstat (limited to 'drivers/clk/hisilicon/clkdivider-hi6220.c')
-rw-r--r-- | drivers/clk/hisilicon/clkdivider-hi6220.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/clkdivider-hi6220.c b/drivers/clk/hisilicon/clkdivider-hi6220.c new file mode 100644 index 000000000..5348bafe6 --- /dev/null +++ b/drivers/clk/hisilicon/clkdivider-hi6220.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Hisilicon hi6220 SoC divider clock driver + * + * Copyright (c) 2015 Hisilicon Limited. + * + * Author: Bintian Wang <bintian.wang@huawei.com> + */ + +#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> + +#include "clk.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, dclk->width); +} + +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; +} |