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authorAlexandre Belloni <alexandre.belloni@free-electrons.com>2014-09-15 18:15:53 +0200
committerNicolas Ferre <nicolas.ferre@atmel.com>2014-09-22 11:38:59 +0200
commitbcc5fd49a0fda5abc22057f65b318788ccb5d2ad (patch)
treeedf97c273ea66306e5a6fdd81e6c5a78d31e8873 /drivers/clk/at91
parent5db722eeba0051c68e638114f6720e715b03cd2c (diff)
clk: at91: add a driver for the h32mx clock
Newer SoCs have two different AHB interconnect. The AHB 32 bits Matrix interconnect (h32mx) has a clock that can be setup at the half of the h64mx clock (which is mck). The h32mx clock can not exceed 90 MHz. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Diffstat (limited to 'drivers/clk/at91')
-rw-r--r--drivers/clk/at91/Makefile1
-rw-r--r--drivers/clk/at91/clk-h32mx.c123
-rw-r--r--drivers/clk/at91/pmc.c6
-rw-r--r--drivers/clk/at91/pmc.h5
4 files changed, 135 insertions, 0 deletions
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 4998aee59267..89a48a7bd5df 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -9,3 +9,4 @@ obj-y += clk-system.o clk-peripheral.o clk-programmable.o
obj-$(CONFIG_HAVE_AT91_UTMI) += clk-utmi.o
obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o
obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o
+obj-$(CONFIG_HAVE_AT91_H32MX) += clk-h32mx.o
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);
+}
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index 524196bb35a5..386999b4f8eb 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -337,6 +337,12 @@ static const struct of_device_id pmc_clk_ids[] __initconst = {
.data = of_at91sam9x5_clk_smd_setup,
},
#endif
+#if defined(CONFIG_HAVE_AT91_H32MX)
+ {
+ .compatible = "atmel,sama5d4-clk-h32mx",
+ .data = of_sama5d4_clk_h32mx_setup,
+ },
+#endif
{ /*sentinel*/ }
};
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 6c7625976113..52d2041fa3f6 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -120,4 +120,9 @@ extern void __init of_at91sam9x5_clk_smd_setup(struct device_node *np,
struct at91_pmc *pmc);
#endif
+#if defined(CONFIG_HAVE_AT91_SMD)
+extern void __init of_sama5d4_clk_h32mx_setup(struct device_node *np,
+ struct at91_pmc *pmc);
+#endif
+
#endif /* __PMC_H_ */