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author | Yoshinori Sato <ysato@users.sourceforge.jp> | 2015-05-08 23:31:57 +0900 |
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committer | Yoshinori Sato <ysato@users.sourceforge.jp> | 2015-06-23 13:35:55 +0900 |
commit | 7b5bb891a6e44bd18bd8661ede2e09ccae258ef5 (patch) | |
tree | bf056a4137d4c3cc58e11107c2bdc7393df13ff2 /drivers/clk/h8300/clk-h8s2678.c | |
parent | 8dbdef22d5a720e66ac3939d4c4f7004ef9dd7b4 (diff) | |
download | linux-7b5bb891a6e44bd18bd8661ede2e09ccae258ef5.tar.bz2 |
h8300: clock driver
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Diffstat (limited to 'drivers/clk/h8300/clk-h8s2678.c')
-rw-r--r-- | drivers/clk/h8300/clk-h8s2678.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/clk/h8300/clk-h8s2678.c b/drivers/clk/h8300/clk-h8s2678.c new file mode 100644 index 000000000000..4de7ee534bfc --- /dev/null +++ b/drivers/clk/h8300/clk-h8s2678.c @@ -0,0 +1,147 @@ +/* + * H8S2678 clock driver + * + * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp> + */ + +#include <linux/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/device.h> +#include <linux/of_address.h> + +static DEFINE_SPINLOCK(clklock); + +#define MAX_FREQ 33333333 +#define MIN_FREQ 8000000 + +struct pll_clock { + struct clk_hw hw; + void __iomem *sckcr; + void __iomem *pllcr; +}; + +#define to_pll_clock(_hw) container_of(_hw, struct pll_clock, hw) + +static unsigned long pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pll_clock *pll_clock = to_pll_clock(hw); + int mul = 1 << (ctrl_inb((unsigned long)pll_clock->pllcr) & 3); + + return parent_rate * mul; +} + +static long pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + int i, m = -1; + long offset[3]; + + if (rate > MAX_FREQ) + rate = MAX_FREQ; + if (rate < MIN_FREQ) + rate = MIN_FREQ; + + for (i = 0; i < 3; i++) + offset[i] = abs(rate - (*prate * (1 << i))); + for (i = 0; i < 3; i++) + if (m < 0) + m = i; + else + m = (offset[i] < offset[m])?i:m; + + return *prate * (1 << m); +} + +static int pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int pll; + unsigned char val; + unsigned long flags; + struct pll_clock *pll_clock = to_pll_clock(hw); + + pll = ((rate / parent_rate) / 2) & 0x03; + spin_lock_irqsave(&clklock, flags); + val = ctrl_inb((unsigned long)pll_clock->sckcr); + val |= 0x08; + ctrl_outb(val, (unsigned long)pll_clock->sckcr); + val = ctrl_inb((unsigned long)pll_clock->pllcr); + val &= ~0x03; + val |= pll; + ctrl_outb(val, (unsigned long)pll_clock->pllcr); + spin_unlock_irqrestore(&clklock, flags); + return 0; +} + +static const struct clk_ops pll_ops = { + .recalc_rate = pll_recalc_rate, + .round_rate = pll_round_rate, + .set_rate = pll_set_rate, +}; + +static void __init h8s2678_pll_clk_setup(struct device_node *node) +{ + unsigned int num_parents; + struct clk *clk; + const char *clk_name = node->name; + const char *parent_name; + struct pll_clock *pll_clock; + struct clk_init_data init; + + num_parents = of_clk_get_parent_count(node); + if (num_parents < 1) { + pr_err("%s: no parent found", clk_name); + return; + } + + + pll_clock = kzalloc(sizeof(struct pll_clock), GFP_KERNEL); + if (!pll_clock) { + pr_err("%s: failed to alloc memory", clk_name); + return; + } + + pll_clock->sckcr = of_iomap(node, 0); + if (pll_clock->sckcr == NULL) { + pr_err("%s: failed to map divide register", clk_name); + goto error; + } + + pll_clock->pllcr = of_iomap(node, 1); + if (pll_clock->pllcr == NULL) { + pr_err("%s: failed to map multiply register", clk_name); + goto error; + } + + parent_name = of_clk_get_parent_name(node, 0); + init.name = clk_name; + init.ops = &pll_ops; + init.flags = CLK_IS_BASIC; + init.parent_names = &parent_name; + init.num_parents = 1; + pll_clock->hw.init = &init; + + clk = clk_register(NULL, &pll_clock->hw); + if (IS_ERR(clk)) + kfree(pll_clock); + if (!IS_ERR(clk)) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + return; + } + pr_err("%s: failed to register %s div clock (%ld)\n", + __func__, clk_name, PTR_ERR(clk)); +error: + if (pll_clock) { + if (pll_clock->sckcr) + iounmap(pll_clock->sckcr); + if (pll_clock->pllcr) + iounmap(pll_clock->pllcr); + kfree(pll_clock); + } +} + +CLK_OF_DECLARE(h8s2678_div_clk, "renesas,h8s2678-pll-clock", + h8s2678_pll_clk_setup); |