summaryrefslogtreecommitdiff
path: root/drivers/clk/at91/clk-plldiv.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/at91/clk-plldiv.c')
-rw-r--r--drivers/clk/at91/clk-plldiv.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-plldiv.c b/drivers/clk/at91/clk-plldiv.c
new file mode 100644
index 000000000000..ea226562bb40
--- /dev/null
+++ b/drivers/clk/at91/clk-plldiv.c
@@ -0,0 +1,135 @@
+/*
+ * 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/of_address.h>
+#include <linux/io.h>
+
+#include "pmc.h"
+
+#define to_clk_plldiv(hw) container_of(hw, struct clk_plldiv, hw)
+
+struct clk_plldiv {
+ struct clk_hw hw;
+ struct at91_pmc *pmc;
+};
+
+static unsigned long clk_plldiv_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_plldiv *plldiv = to_clk_plldiv(hw);
+ struct at91_pmc *pmc = plldiv->pmc;
+
+ if (pmc_read(pmc, AT91_PMC_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);
+ struct at91_pmc *pmc = plldiv->pmc;
+ u32 tmp;
+
+ if (parent_rate != rate && (parent_rate / 2) != rate)
+ return -EINVAL;
+
+ pmc_lock(pmc);
+ tmp = pmc_read(pmc, AT91_PMC_MCKR) & ~AT91_PMC_PLLADIV2;
+ if ((parent_rate / 2) == rate)
+ tmp |= AT91_PMC_PLLADIV2;
+ pmc_write(pmc, AT91_PMC_MCKR, tmp);
+ pmc_unlock(pmc);
+
+ 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 * __init
+at91_clk_register_plldiv(struct at91_pmc *pmc, const char *name,
+ const char *parent_name)
+{
+ struct clk_plldiv *plldiv;
+ struct clk *clk = NULL;
+ struct clk_init_data init;
+
+ 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->pmc = pmc;
+
+ clk = clk_register(NULL, &plldiv->hw);
+
+ if (IS_ERR(clk))
+ kfree(plldiv);
+
+ return clk;
+}
+
+static void __init
+of_at91_clk_plldiv_setup(struct device_node *np, struct at91_pmc *pmc)
+{
+ struct clk *clk;
+ const char *parent_name;
+ const char *name = np->name;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ clk = at91_clk_register_plldiv(pmc, name, parent_name);
+
+ if (IS_ERR(clk))
+ return;
+
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ return;
+}
+
+void __init of_at91sam9x5_clk_plldiv_setup(struct device_node *np,
+ struct at91_pmc *pmc)
+{
+ of_at91_clk_plldiv_setup(np, pmc);
+}