[PATCH v2 5/9] clk: mvebu: add clock gating control provider for DT
Andrew Lunn
andrew at lunn.ch
Sat Nov 17 09:22:26 EST 2012
From: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
This driver allows to provide DT clocks for clock gates found on
Marvell Dove and Kirkwood SoCs. The clock gates are referenced by
the phandle index of the corresponding bit in the clock gating control
register to ease lookup in the datasheet.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
.../bindings/clock/mvebu-gated-clock.txt | 76 +++++++++
drivers/clk/mvebu/Kconfig | 2 +
drivers/clk/mvebu/Makefile | 1 +
drivers/clk/mvebu/clk-gating-ctrl.c | 177 ++++++++++++++++++++
include/linux/clk/mvebu.h | 1 +
5 files changed, 257 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt
create mode 100644 drivers/clk/mvebu/clk-gating-ctrl.c
diff --git a/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt b/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt
new file mode 100644
index 0000000..4ad8ccd
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt
@@ -0,0 +1,76 @@
+* Gated Clock bindings for Marvell Orion SoCs
+
+Marvell Dove and Kirkwood allow some peripheral clocks to be gated to save
+some power. The clock consumer should specify the desired clock by having
+the clock ID in its "clocks" phandle cell. The clock ID is directly mapped to
+the corresponding clock gating control bit in HW to ease manual clock lookup
+in datasheet.
+
+The following is a list of provided IDs for Dove:
+ID Clock Peripheral
+-----------------------------------
+0 usb0 USB Host 0
+1 usb1 USB Host 1
+2 ge Gigabit Ethernet
+3 sata SATA Host
+4 pex0 PCIe Cntrl 0
+5 pex1 PCIe Cntrl 1
+8 sdio0 SDHCI Host 0
+9 sdio1 SDHCI Host 1
+10 nand NAND Cntrl
+11 camera Camera Cntrl
+12 i2s0 I2S Cntrl 0
+13 i2s1 I2S Cntrl 1
+15 crypto CESA engine
+21 ac97 AC97 Cntrl
+22 pdma Peripheral DMA
+23 xor0 XOR DMA 0
+24 xor1 XOR DMA 1
+30 gephy Gigabit Ethernel PHY
+Note: gephy(30) is implemented as a parent clock of ge(2)
+
+The following is a list of provided IDs for Kirkwood:
+ID Clock Peripheral
+-----------------------------------
+0 ge0 Gigabit Ethernet 0
+2 pex0 PCIe Cntrl 0
+3 usb0 USB Host 0
+4 sdio SDIO Cntrl
+5 tsu Transp. Stream Unit
+6 dunit SDRAM Cntrl
+7 runit Runit
+8 xor0 XOR DMA 0
+9 audio I2S Cntrl 0
+14 sata0 SATA Host 0
+15 sata1 SATA Host 1
+16 xor1 XOR DMA 1
+17 crypto CESA engine
+18 pex1 PCIe Cntrl 1
+19 ge1 Gigabit Ethernet 0
+20 tdm Time Division Mplx
+
+Required properties:
+- compatible : shall be one of the following:
+ "marvell,dove-gating-clock" - for Dove SoC clock gating
+ "marvell,kirkwood-gating-clock" - for Kirkwood SoC clock gating
+- reg : shall be the register address of the Clock Gating Control register
+- #clock-cells : from common clock binding; shall be set to 1
+
+Optional properties:
+- clocks : default parent clock phandle (e.g. tclk)
+
+Example:
+
+gate_clk: clock-gating-control at d0038 {
+ compatible = "marvell,dove-gating-clock";
+ reg = <0xd0038 0x4>;
+ /* default parent clock is tclk */
+ clocks = <&core_clk 0>;
+ #clock-cells = <1>;
+};
+
+sdio0: sdio at 92000 {
+ compatible = "marvell,dove-sdhci";
+ /* get clk gate bit 8 (sdio0) */
+ clocks = <&gate_clk 8>;
+};
diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig
index 1dd93ad..57323fd 100644
--- a/drivers/clk/mvebu/Kconfig
+++ b/drivers/clk/mvebu/Kconfig
@@ -4,3 +4,5 @@ config MVEBU_CLK_CORE
config MVEBU_CLK_CPU
bool
+config MVEBU_CLK_GATING
+ bool
diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index 93da083..58df3dc 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -1,2 +1,3 @@
obj-$(CONFIG_MVEBU_CLK_CORE) += clk.o clk-core.o
obj-$(CONFIG_MVEBU_CLK_CPU) += clk-cpu.o
+obj-$(CONFIG_MVEBU_CLK_GATING) += clk-gating-ctrl.o
diff --git a/drivers/clk/mvebu/clk-gating-ctrl.c b/drivers/clk/mvebu/clk-gating-ctrl.c
new file mode 100644
index 0000000..424faff
--- /dev/null
+++ b/drivers/clk/mvebu/clk-gating-ctrl.c
@@ -0,0 +1,177 @@
+/*
+ * Marvell MVEBU clock gating control.
+ *
+ * Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
+ * Andrew Lunn <andrew at lunn.ch>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/mvebu.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+struct mvebu_gating_ctrl {
+ spinlock_t lock;
+ struct clk **gates;
+ int num_gates;
+};
+
+struct mvebu_soc_descr {
+ const char *name;
+ const char *parent;
+ int bit_idx;
+};
+
+#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
+
+static struct clk __init *mvebu_clk_gating_get_src(
+ struct of_phandle_args *clkspec, void *data)
+{
+ struct mvebu_gating_ctrl *ctrl = (struct mvebu_gating_ctrl *)data;
+ int n;
+
+ if (clkspec->args_count < 1)
+ return ERR_PTR(-EINVAL);
+
+ for (n = 0; n < ctrl->num_gates; n++) {
+ struct clk_gate *gate =
+ to_clk_gate(__clk_get_hw(ctrl->gates[n]));
+ if (clkspec->args[0] == gate->bit_idx)
+ return ctrl->gates[n];
+ }
+ return ERR_PTR(-ENODEV);
+}
+
+static void __init mvebu_clk_gating_setup(
+ struct device_node *np, const struct mvebu_soc_descr *descr)
+{
+ struct mvebu_gating_ctrl *ctrl;
+ struct clk *clk;
+ void __iomem *base;
+ const char *default_parent = NULL;
+ int n;
+
+ base = of_iomap(np, 0);
+
+ clk = of_clk_get(np, 0);
+ if (!IS_ERR(clk)) {
+ default_parent = __clk_get_name(clk);
+ clk_put(clk);
+ }
+
+ ctrl = kzalloc(sizeof(struct mvebu_gating_ctrl), GFP_KERNEL);
+ if (WARN_ON(!ctrl))
+ return;
+
+ spin_lock_init(&ctrl->lock);
+
+ /*
+ * Count, allocate, and register clock gates
+ */
+ for (n = 0; descr[n].name;)
+ n++;
+
+ ctrl->num_gates = n;
+ ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *),
+ GFP_KERNEL);
+ if (WARN_ON(!ctrl->gates)) {
+ kfree(ctrl);
+ return;
+ }
+
+ for (n = 0; n < ctrl->num_gates; n++) {
+ const char *parent =
+ (descr[n].parent) ? descr[n].parent : default_parent;
+ ctrl->gates[n] = clk_register_gate(NULL, descr[n].name, parent,
+ 0, base, descr[n].bit_idx, 0, &ctrl->lock);
+ WARN_ON(IS_ERR(ctrl->gates[n]));
+ }
+ of_clk_add_provider(np, mvebu_clk_gating_get_src, ctrl);
+}
+
+/*
+ * SoC specific clock gating control
+ */
+
+#ifdef CONFIG_ARCH_DOVE
+static const struct mvebu_soc_descr __initconst dove_gating_descr[] = {
+ { "usb0", NULL, 0 },
+ { "usb1", NULL, 1 },
+ { "ge", "gephy", 2 },
+ { "sata", NULL, 3 },
+ { "pex0", NULL, 4 },
+ { "pex1", NULL, 5 },
+ { "sdio0", NULL, 8 },
+ { "sdio1", NULL, 9 },
+ { "nand", NULL, 10 },
+ { "camera", NULL, 11 },
+ { "i2s0", NULL, 12 },
+ { "i2s1", NULL, 13 },
+ { "crypto", NULL, 15 },
+ { "ac97", NULL, 21 },
+ { "pdma", NULL, 22 },
+ { "xor0", NULL, 23 },
+ { "xor1", NULL, 24 },
+ { "gephy", NULL, 30 },
+ { }
+};
+#endif
+
+#ifdef CONFIG_ARCH_KIRKWOOD
+static const struct mvebu_soc_descr __initconst kirkwood_gating_descr[] = {
+ { "ge0", NULL, 0 },
+ { "pex0", NULL, 2 },
+ { "usb0", NULL, 3 },
+ { "sdio", NULL, 4 },
+ { "tsu", NULL, 5 },
+ { "runit", NULL, 7 },
+ { "xor0", NULL, 8 },
+ { "audio", NULL, 9 },
+ { "sata0", NULL, 14 },
+ { "sata1", NULL, 15 },
+ { "xor1", NULL, 16 },
+ { "crypto", NULL, 17 },
+ { "pex1", NULL, 18 },
+ { "ge1", NULL, 19 },
+ { "tdm", NULL, 20 },
+ { }
+};
+#endif
+
+static const __initdata struct of_device_id clk_gating_match[] = {
+#ifdef CONFIG_ARCH_DOVE
+ {
+ .compatible = "marvell,dove-gating-clock",
+ .data = dove_gating_descr,
+ },
+#endif
+
+#ifdef CONFIG_ARCH_KIRKWOOD
+ {
+ .compatible = "marvell,kirkwood-gating-clock",
+ .data = kirkwood_gating_descr,
+ },
+#endif
+
+ { }
+};
+
+void __init mvebu_clk_gating_init(void)
+{
+ struct device_node *np;
+
+ for_each_matching_node(np, clk_gating_match) {
+ const struct of_device_id *match =
+ of_match_node(clk_gating_match, np);
+ mvebu_clk_gating_setup(np,
+ (const struct mvebu_soc_descr *)match->data);
+ }
+}
diff --git a/include/linux/clk/mvebu.h b/include/linux/clk/mvebu.h
index 8c4ae71..70c366f 100644
--- a/include/linux/clk/mvebu.h
+++ b/include/linux/clk/mvebu.h
@@ -18,5 +18,6 @@
#define __CLK_MVEBU_H_
void __init mvebu_clocks_init(void);
+void mvebu_clk_gating_init(void);
#endif
--
1.7.10.4
More information about the linux-arm-kernel
mailing list