These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / clk / h8300 / clk-h8s2678.c

diff --git a/kernel/drivers/clk/h8300/clk-h8s2678.c b/kernel/drivers/clk/h8300/clk-h8s2678.c
new file mode 100644 (file)
index 0000000..6cf38dc
--- /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);