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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/clk/h8300/clk-h8s2678.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clk/h8300/clk-h8s2678.c')
-rw-r--r-- | drivers/clk/h8300/clk-h8s2678.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/drivers/clk/h8300/clk-h8s2678.c b/drivers/clk/h8300/clk-h8s2678.c new file mode 100644 index 000000000..b68045d8b --- /dev/null +++ b/drivers/clk/h8300/clk-h8s2678.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * H8S2678 clock driver + * + * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp> + */ + +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/device.h> +#include <linux/of_address.h> +#include <linux/slab.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 << (readb(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 = readb(pll_clock->sckcr); + val |= 0x08; + writeb(val, pll_clock->sckcr); + val = readb(pll_clock->pllcr); + val &= ~0x03; + val |= pll; + writeb(val, 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; + const char *clk_name = node->name; + const char *parent_name; + struct pll_clock *pll_clock; + struct clk_init_data init; + int ret; + + num_parents = of_clk_get_parent_count(node); + if (!num_parents) { + pr_err("%s: no parent found\n", clk_name); + return; + } + + + pll_clock = kzalloc(sizeof(*pll_clock), GFP_KERNEL); + if (!pll_clock) + return; + + pll_clock->sckcr = of_iomap(node, 0); + if (pll_clock->sckcr == NULL) { + pr_err("%s: failed to map divide register\n", clk_name); + goto free_clock; + } + + pll_clock->pllcr = of_iomap(node, 1); + if (pll_clock->pllcr == NULL) { + pr_err("%s: failed to map multiply register\n", clk_name); + goto unmap_sckcr; + } + + 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; + + ret = clk_hw_register(NULL, &pll_clock->hw); + if (ret) { + pr_err("%s: failed to register %s div clock (%d)\n", + __func__, clk_name, ret); + goto unmap_pllcr; + } + + of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clock->hw); + return; + +unmap_pllcr: + iounmap(pll_clock->pllcr); +unmap_sckcr: + iounmap(pll_clock->sckcr); +free_clock: + kfree(pll_clock); +} + +CLK_OF_DECLARE(h8s2678_div_clk, "renesas,h8s2678-pll-clock", + h8s2678_pll_clk_setup); |