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path: root/drivers/clk/at91/clk-h32mx.c
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Diffstat (limited to 'drivers/clk/at91/clk-h32mx.c')
-rw-r--r--drivers/clk/at91/clk-h32mx.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-h32mx.c b/drivers/clk/at91/clk-h32mx.c
new file mode 100644
index 000000000000..152dcb3f7b5f
--- /dev/null
+++ b/drivers/clk/at91/clk-h32mx.c
@@ -0,0 +1,123 @@
+/*
+ * clk-h32mx.c
+ *
+ * Copyright (C) 2014 Atmel
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.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/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "pmc.h"
+
+#define H32MX_MAX_FREQ 90000000
+
+struct clk_sama5d4_h32mx {
+ struct clk_hw hw;
+ struct at91_pmc *pmc;
+};
+
+#define to_clk_sama5d4_h32mx(hw) container_of(hw, struct clk_sama5d4_h32mx, hw)
+
+static unsigned long clk_sama5d4_h32mx_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw);
+
+ if (pmc_read(h32mxclk->pmc, AT91_PMC_MCKR) & AT91_PMC_H32MXDIV)
+ return parent_rate / 2;
+
+ if (parent_rate > H32MX_MAX_FREQ)
+ pr_warn("H32MX clock is too fast\n");
+ return parent_rate;
+}
+
+static long clk_sama5d4_h32mx_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_sama5d4_h32mx_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw);
+ struct at91_pmc *pmc = h32mxclk->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_H32MXDIV;
+ if ((parent_rate / 2) == rate)
+ tmp |= AT91_PMC_H32MXDIV;
+ pmc_write(pmc, AT91_PMC_MCKR, tmp);
+ pmc_unlock(pmc);
+
+ return 0;
+}
+
+static const struct clk_ops h32mx_ops = {
+ .recalc_rate = clk_sama5d4_h32mx_recalc_rate,
+ .round_rate = clk_sama5d4_h32mx_round_rate,
+ .set_rate = clk_sama5d4_h32mx_set_rate,
+};
+
+void __init of_sama5d4_clk_h32mx_setup(struct device_node *np,
+ struct at91_pmc *pmc)
+{
+ struct clk_sama5d4_h32mx *h32mxclk;
+ struct clk_init_data init;
+ const char *parent_name;
+ struct clk *clk;
+
+ h32mxclk = kzalloc(sizeof(*h32mxclk), GFP_KERNEL);
+ if (!h32mxclk)
+ return;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ init.name = np->name;
+ init.ops = &h32mx_ops;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+ init.flags = CLK_SET_RATE_GATE;
+
+ h32mxclk->hw.init = &init;
+ h32mxclk->pmc = pmc;
+
+ clk = clk_register(NULL, &h32mxclk->hw);
+ if (!clk)
+ return;
+
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}