diff options
author | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
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committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/drivers/clk/h8300/clk-h8s2678.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/drivers/clk/h8300/clk-h8s2678.c')
-rw-r--r-- | kernel/drivers/clk/h8300/clk-h8s2678.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/kernel/drivers/clk/h8300/clk-h8s2678.c b/kernel/drivers/clk/h8300/clk-h8s2678.c new file mode 100644 index 000000000..6cf38dc1c --- /dev/null +++ b/kernel/drivers/clk/h8300/clk-h8s2678.c @@ -0,0 +1,143 @@ +/* + * 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) +{ + 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(*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", 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", 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; + + clk = clk_register(NULL, &pll_clock->hw); + if (IS_ERR(clk)) { + pr_err("%s: failed to register %s div clock (%ld)\n", + __func__, clk_name, PTR_ERR(clk)); + goto unmap_pllcr; + } + + of_clk_add_provider(node, of_clk_src_simple_get, clk); + 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); |