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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.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-h32mx.c b/drivers/clk/at91/clk-h32mx.c
new file mode 100644
index 000000000..1e6c12eed
--- /dev/null
+++ b/drivers/clk/at91/clk-h32mx.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * clk-h32mx.c
+ *
+ * Copyright (C) 2014 Atmel
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "pmc.h"
+
+#define H32MX_MAX_FREQ 90000000
+
+struct clk_sama5d4_h32mx {
+ struct clk_hw hw;
+ struct regmap *regmap;
+};
+
+#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);
+ unsigned int mckr;
+
+ regmap_read(h32mxclk->regmap, AT91_PMC_MCKR, &mckr);
+ if (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);
+ u32 mckr = 0;
+
+ if (parent_rate != rate && (parent_rate / 2) != rate)
+ return -EINVAL;
+
+ if ((parent_rate / 2) == rate)
+ mckr = AT91_PMC_H32MXDIV;
+
+ regmap_update_bits(h32mxclk->regmap, AT91_PMC_MCKR,
+ AT91_PMC_H32MXDIV, mckr);
+
+ 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,
+};
+
+struct clk_hw * __init
+at91_clk_register_h32mx(struct regmap *regmap, const char *name,
+ const char *parent_name)
+{
+ struct clk_sama5d4_h32mx *h32mxclk;
+ struct clk_init_data init;
+ int ret;
+
+ h32mxclk = kzalloc(sizeof(*h32mxclk), GFP_KERNEL);
+ if (!h32mxclk)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = 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->regmap = regmap;
+
+ ret = clk_hw_register(NULL, &h32mxclk->hw);
+ if (ret) {
+ kfree(h32mxclk);
+ return ERR_PTR(ret);
+ }
+
+ return &h32mxclk->hw;
+}