[PATCHv2 2/8] clk: at91: add a driver for the h32mx clock
Alexandre Belloni
alexandre.belloni at free-electrons.com
Fri Sep 12 08:43:01 PDT 2014
Newer SoCs have two different peripheral master clocks, h32mx is able to divide
mck for slower peripherals.
Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
---
Cc: Mike Turquette <mturquette at linaro.org>
.../devicetree/bindings/clock/at91-clock.txt | 15 +++
arch/arm/mach-at91/Kconfig | 3 +
drivers/clk/at91/Makefile | 1 +
drivers/clk/at91/clk-h32mx.c | 121 +++++++++++++++++++++
drivers/clk/at91/pmc.c | 6 +
drivers/clk/at91/pmc.h | 5 +
include/linux/clk/at91_pmc.h | 1 +
7 files changed, 152 insertions(+)
create mode 100644 drivers/clk/at91/clk-h32mx.c
diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index b3d544ca522a..c8dcbbd242e5 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -74,6 +74,9 @@ Required properties:
"atmel,at91sam9x5-clk-utmi":
at91 utmi clock
+ "atmel,sama5d4-clk-h32mx":
+ at91 h32mx clock
+
Required properties for SCKC node:
- reg : defines the IO memory reserved for the SCKC.
- #size-cells : shall be 0 (reg is used to encode clk id).
@@ -447,3 +450,15 @@ For example:
#clock-cells = <0>;
clocks = <&main>;
};
+
+Required properties for h32mx clock:
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : shall be the master clock source phandle.
+
+For example:
+ h32ck: h32mxck {
+ #clock-cells = <0>;
+ compatible = "atmel,sama5d4-clk-h32mx";
+ clocks = <&mck>;
+ };
+
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 6eb3c658761d..a2c8ecb10730 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -39,6 +39,9 @@ config AT91_SAM9_TIME
config HAVE_AT91_SMD
bool
+config HAVE_AT91_H64MX
+ bool
+
config SOC_AT91SAM9
bool
select AT91_SAM9_TIME
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 4998aee59267..b2d43ff8112b 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_H64MX) += 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..21a2f3630a43
--- /dev/null
+++ b/drivers/clk/at91/clk-h32mx.c
@@ -0,0 +1,121 @@
+/*
+ * drivers/clk/at91/clk-h32mx.c
+ *
+ * Copyright (C) 2014 Atmel
+ *
+ * Alexandre Belloni <alexandre.belloni at 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"
+
+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 > 90000000)
+ pr_warn("H32 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..0d98b3f2b780 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_H64MX)
+ {
+ .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_ */
diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h
index de4268d4987a..c8e3b3d1eded 100644
--- a/include/linux/clk/at91_pmc.h
+++ b/include/linux/clk/at91_pmc.h
@@ -125,6 +125,7 @@ extern void __iomem *at91_pmc_base;
#define AT91_PMC_PLLADIV2 (1 << 12) /* PLLA divisor by 2 [some SAM9 only] */
#define AT91_PMC_PLLADIV2_OFF (0 << 12)
#define AT91_PMC_PLLADIV2_ON (1 << 12)
+#define AT91_PMC_H32MXDIV BIT(24)
#define AT91_PMC_USB 0x38 /* USB Clock Register [some SAM9 only] */
#define AT91_PMC_USBS (0x1 << 0) /* USB OHCI Input clock selection */
--
1.9.1
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