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path: root/drivers/clk/h8300/clk-h8s2678.c
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Diffstat (limited to 'drivers/clk/h8300/clk-h8s2678.c')
-rw-r--r--drivers/clk/h8300/clk-h8s2678.c147
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);