summaryrefslogtreecommitdiffstats
path: root/drivers/clk/at91/clk-plldiv.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/clk/at91/clk-plldiv.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-plldiv.c b/drivers/clk/at91/clk-plldiv.c
new file mode 100644
index 000000000..b4afaf22f
--- /dev/null
+++ b/drivers/clk/at91/clk-plldiv.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+#define to_clk_plldiv(hw) container_of(hw, struct clk_plldiv, hw)
+
+struct clk_plldiv {
+ struct clk_hw hw;
+ struct regmap *regmap;
+};
+
+static unsigned long clk_plldiv_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_plldiv *plldiv = to_clk_plldiv(hw);
+ unsigned int mckr;
+
+ regmap_read(plldiv->regmap, AT91_PMC_MCKR, &mckr);
+
+ if (mckr & AT91_PMC_PLLADIV2)
+ return parent_rate / 2;
+
+ return parent_rate;
+}
+
+static long clk_plldiv_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned long div;
+
+ if (rate > *parent_rate)
+ return *parent_rate;
+ div = *parent_rate / 2;
+ if (rate < div)
+ return div;
+
+ if (rate - div < *parent_rate - rate)
+ return div;
+
+ return *parent_rate;
+}
+
+static int clk_plldiv_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_plldiv *plldiv = to_clk_plldiv(hw);
+
+ if ((parent_rate != rate) && (parent_rate / 2 != rate))
+ return -EINVAL;
+
+ regmap_update_bits(plldiv->regmap, AT91_PMC_MCKR, AT91_PMC_PLLADIV2,
+ parent_rate != rate ? AT91_PMC_PLLADIV2 : 0);
+
+ return 0;
+}
+
+static const struct clk_ops plldiv_ops = {
+ .recalc_rate = clk_plldiv_recalc_rate,
+ .round_rate = clk_plldiv_round_rate,
+ .set_rate = clk_plldiv_set_rate,
+};
+
+static struct clk_hw * __init
+at91_clk_register_plldiv(struct regmap *regmap, const char *name,
+ const char *parent_name)
+{
+ struct clk_plldiv *plldiv;
+ struct clk_hw *hw;
+ struct clk_init_data init;
+ int ret;
+
+ plldiv = kzalloc(sizeof(*plldiv), GFP_KERNEL);
+ if (!plldiv)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &plldiv_ops;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+ init.flags = CLK_SET_RATE_GATE;
+
+ plldiv->hw.init = &init;
+ plldiv->regmap = regmap;
+
+ hw = &plldiv->hw;
+ ret = clk_hw_register(NULL, &plldiv->hw);
+ if (ret) {
+ kfree(plldiv);
+ hw = ERR_PTR(ret);
+ }
+
+ return hw;
+}
+
+static void __init
+of_at91sam9x5_clk_plldiv_setup(struct device_node *np)
+{
+ struct clk_hw *hw;
+ const char *parent_name;
+ const char *name = np->name;
+ struct regmap *regmap;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ regmap = syscon_node_to_regmap(of_get_parent(np));
+ if (IS_ERR(regmap))
+ return;
+
+ hw = at91_clk_register_plldiv(regmap, name, parent_name);
+ if (IS_ERR(hw))
+ return;
+
+ of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+CLK_OF_DECLARE(at91sam9x5_clk_plldiv, "atmel,at91sam9x5-clk-plldiv",
+ of_at91sam9x5_clk_plldiv_setup);