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path: root/drivers/clk/shmobile/clk-rz.c
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Diffstat (limited to 'drivers/clk/shmobile/clk-rz.c')
-rw-r--r--drivers/clk/shmobile/clk-rz.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-rz.c b/drivers/clk/shmobile/clk-rz.c
new file mode 100644
index 000000000000..7e68e8630962
--- /dev/null
+++ b/drivers/clk/shmobile/clk-rz.c
@@ -0,0 +1,103 @@
+/*
+ * rz Core CPG Clocks
+ *
+ * Copyright (C) 2013 Ideas On Board SPRL
+ * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+struct rz_cpg {
+ struct clk_onecell_data data;
+ void __iomem *reg;
+};
+
+#define CPG_FRQCR 0x10
+#define CPG_FRQCR2 0x14
+
+/* -----------------------------------------------------------------------------
+ * Initialization
+ */
+
+static struct clk * __init
+rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name)
+{
+ u32 val;
+ unsigned mult;
+ static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 };
+
+ if (strcmp(name, "pll") == 0) {
+ /* FIXME: cpg_mode should be read from GPIO. But no GPIO support yet */
+ unsigned cpg_mode = 0; /* hardcoded to EXTAL for now */
+ const char *parent_name = of_clk_get_parent_name(np, cpg_mode);
+
+ mult = cpg_mode ? (32 / 4) : 30;
+
+ return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1);
+ }
+
+ /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */
+ if (!cpg->reg)
+ return ERR_PTR(-ENXIO);
+
+ /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3)
+ * and the constraint that always g <= i. To get the rz platform started,
+ * let them run at fixed current speed and implement the details later.
+ */
+ if (strcmp(name, "i") == 0)
+ val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3;
+ else if (strcmp(name, "g") == 0)
+ val = clk_readl(cpg->reg + CPG_FRQCR2) & 3;
+ else
+ return ERR_PTR(-EINVAL);
+
+ mult = frqcr_tab[val];
+ return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3);
+}
+
+static void __init rz_cpg_clocks_init(struct device_node *np)
+{
+ struct rz_cpg *cpg;
+ struct clk **clks;
+ unsigned i;
+ int num_clks;
+
+ num_clks = of_property_count_strings(np, "clock-output-names");
+ if (WARN(num_clks <= 0, "can't count CPG clocks\n"))
+ return;
+
+ cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
+ clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
+ BUG_ON(!cpg || !clks);
+
+ cpg->data.clks = clks;
+ cpg->data.clk_num = num_clks;
+
+ cpg->reg = of_iomap(np, 0);
+
+ for (i = 0; i < num_clks; ++i) {
+ const char *name;
+ struct clk *clk;
+
+ of_property_read_string_index(np, "clock-output-names", i, &name);
+
+ clk = rz_cpg_register_clock(np, cpg, name);
+ if (IS_ERR(clk))
+ pr_err("%s: failed to register %s %s clock (%ld)\n",
+ __func__, np->name, name, PTR_ERR(clk));
+ else
+ cpg->data.clks[i] = clk;
+ }
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+}
+CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);