diff mbox

[3/3] clk: hisilicon: add CRG driver for hi3519 soc

Message ID 1461397230-1757-4-git-send-email-xuejiancheng@hisilicon.com (mailing list archive)
State Accepted, archived
Delegated to: Stephen Boyd
Headers show

Commit Message

Jiancheng Xue April 23, 2016, 7:40 a.m. UTC 
The CRG(Clock and Reset Generator) block provides clock
and reset signals for other modules in hi3519 soc.

Signed-off-by: Jiancheng Xue <xuejiancheng@hisilicon.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/clock/hi3519-crg.txt       |  46 ++++++++
 drivers/clk/hisilicon/Kconfig                      |   8 ++
 drivers/clk/hisilicon/Makefile                     |   1 +
 drivers/clk/hisilicon/clk-hi3519.c                 | 131 +++++++++++++++++++++
 include/dt-bindings/clock/hi3519-clock.h           |  40 +++++++
 5 files changed, 226 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/hi3519-crg.txt
 create mode 100644 drivers/clk/hisilicon/clk-hi3519.c
 create mode 100644 include/dt-bindings/clock/hi3519-clock.h

Comments

Stephen Boyd May 6, 2016, 6:19 p.m. UTC | #1 
On 04/23, Jiancheng Xue wrote:
> +
> +static int hi3519_clk_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct hisi_clock_data *clk_data;
> +	struct hisi_reset_controller *rstc;
> +
> +	rstc = hisi_reset_init(np);
> +	if (!rstc)
> +		return -ENOMEM;
> +
> +	clk_data = hisi_clk_init(np, HI3519_NR_CLKS);

This creates and registers a clk provider...

> +	if (!clk_data) {
> +		hisi_reset_exit(rstc);
> +		return -ENODEV;
> +	}
> +
> +	hisi_clk_register_fixed_rate(hi3519_fixed_rate_clks,
> +				     ARRAY_SIZE(hi3519_fixed_rate_clks),
> +				     clk_data);
> +	hisi_clk_register_mux(hi3519_mux_clks, ARRAY_SIZE(hi3519_mux_clks),
> +					clk_data);
> +	hisi_clk_register_gate(hi3519_gate_clks,
> +			ARRAY_SIZE(hi3519_gate_clks), clk_data);
> +

And then this actually populates those clks into the provider's
array of clks..

That isn't good because now we have an ordering problem where the
provider has published itself before it can provide clks to
consumers. Hopefully no race condition arises!

Also, we don't check errors here upon registering clks. Not good
in the case of probe defer or something.

Finally, we should still have a driver remove path even if it's
builtin because userspace can unbind drivers, unless we configure
the struct driver to prevent that. Please do one or the other
here (I would guess you're leaning toward the driver attribute to
prevent unbinding).

> +	return 0;
> +}
> +
> +static const struct of_device_id hi3519_clk_match_table[] = {
> +	{ .compatible = "hisilicon,hi3519-crg" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, hi3519_clk_match_table);
> +
> +static struct platform_driver hi3519_clk_driver = {
> +	.probe          = hi3519_clk_probe,
> +	.driver         = {
> +		.name   = "hi3519-clk",
> +		.of_match_table = hi3519_clk_match_table,
> +	},
> +};
> +

Anyway, I applied this to a new immutable branch clk-hi3519 in
the clk tree and merged it into clk-next. Please send follow up
patches to fix these theoretical problems.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/clock/hi3519-crg.txt b/Documentation/devicetree/bindings/clock/hi3519-crg.txt
new file mode 100644
index 0000000..acd1f23
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/hi3519-crg.txt
@@ -0,0 +1,46 @@ 
+* Hisilicon Hi3519 Clock and Reset Generator(CRG)
+
+The Hi3519 CRG module provides clock and reset signals to various
+controllers within the SoC.
+
+This binding uses the following bindings:
+    Documentation/devicetree/bindings/clock/clock-bindings.txt
+    Documentation/devicetree/bindings/reset/reset.txt
+
+Required Properties:
+
+- compatible: should be one of the following.
+  - "hisilicon,hi3519-crg" - controller compatible with Hi3519 SoC.
+
+- reg: physical base address of the controller and length of memory mapped
+  region.
+
+- #clock-cells: should be 1.
+
+Each clock is assigned an identifier and client nodes use this identifier
+to specify the clock which they consume.
+
+All these identifier could be found in <dt-bindings/clock/hi3519-clock.h>.
+
+- #reset-cells: should be 2.
+
+A reset signal can be controlled by writing a bit register in the CRG module.
+The reset specifier consists of two cells. The first cell represents the
+register offset relative to the base address. The second cell represents the
+bit index in the register.
+
+Example: CRG nodes
+CRG: clock-reset-controller@12010000 {
+	compatible = "hisilicon,hi3519-crg";
+	reg = <0x12010000 0x10000>;
+	#clock-cells = <1>;
+	#reset-cells = <2>;
+};
+
+Example: consumer nodes
+i2c0: i2c@12110000 {
+	compatible = "hisilicon,hi3519-i2c";
+	reg = <0x12110000 0x1000>;
+	clocks = <&CRG HI3519_I2C0_RST>;
+	resets = <&CRG 0xe4 0>;
+};
diff --git a/drivers/clk/hisilicon/Kconfig b/drivers/clk/hisilicon/Kconfig
index 3cd349c..3f537a0 100644
--- a/drivers/clk/hisilicon/Kconfig
+++ b/drivers/clk/hisilicon/Kconfig
@@ -1,3 +1,11 @@ 
+config COMMON_CLK_HI3519
+	tristate "Hi3519 Clock Driver"
+	depends on ARCH_HISI || COMPILE_TEST
+	select RESET_HISI
+	default ARCH_HISI
+	help
+	  Build the clock driver for hi3519.
+
 config COMMON_CLK_HI6220
 	bool "Hi6220 Clock Driver"
 	depends on ARCH_HISI || COMPILE_TEST
diff --git a/drivers/clk/hisilicon/Makefile b/drivers/clk/hisilicon/Makefile
index c037753..e169ec7 100644
--- a/drivers/clk/hisilicon/Makefile
+++ b/drivers/clk/hisilicon/Makefile
@@ -7,6 +7,7 @@  obj-y	+= clk.o clkgate-separated.o clkdivider-hi6220.o
 obj-$(CONFIG_ARCH_HI3xxx)	+= clk-hi3620.o
 obj-$(CONFIG_ARCH_HIP04)	+= clk-hip04.o
 obj-$(CONFIG_ARCH_HIX5HD2)	+= clk-hix5hd2.o
+obj-$(CONFIG_COMMON_CLK_HI3519)	+= clk-hi3519.o
 obj-$(CONFIG_COMMON_CLK_HI6220)	+= clk-hi6220.o
 obj-$(CONFIG_RESET_HISI)	+= reset.o
 obj-$(CONFIG_STUB_CLK_HI6220)	+= clk-hi6220-stub.o
diff --git a/drivers/clk/hisilicon/clk-hi3519.c b/drivers/clk/hisilicon/clk-hi3519.c
new file mode 100644
index 0000000..715c730
--- /dev/null
+++ b/drivers/clk/hisilicon/clk-hi3519.c
@@ -0,0 +1,131 @@ 
+/*
+ * Hi3519 Clock Driver
+ *
+ * Copyright (c) 2015-2016 HiSilicon Technologies Co., Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <dt-bindings/clock/hi3519-clock.h>
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include "clk.h"
+#include "reset.h"
+
+#define HI3519_INNER_CLK_OFFSET	64
+#define HI3519_FIXED_24M	65
+#define HI3519_FIXED_50M	66
+#define HI3519_FIXED_75M	67
+#define HI3519_FIXED_125M	68
+#define HI3519_FIXED_150M	69
+#define HI3519_FIXED_200M	70
+#define HI3519_FIXED_250M	71
+#define HI3519_FIXED_300M	72
+#define HI3519_FIXED_400M	73
+#define HI3519_FMC_MUX		74
+
+#define HI3519_NR_CLKS		128
+
+static const struct hisi_fixed_rate_clock hi3519_fixed_rate_clks[] = {
+	{ HI3519_FIXED_24M, "24m", NULL, 0, 24000000, },
+	{ HI3519_FIXED_50M, "50m", NULL, 0, 50000000, },
+	{ HI3519_FIXED_75M, "75m", NULL, 0, 75000000, },
+	{ HI3519_FIXED_125M, "125m", NULL, 0, 125000000, },
+	{ HI3519_FIXED_150M, "150m", NULL, 0, 150000000, },
+	{ HI3519_FIXED_200M, "200m", NULL, 0, 200000000, },
+	{ HI3519_FIXED_250M, "250m", NULL, 0, 250000000, },
+	{ HI3519_FIXED_300M, "300m", NULL, 0, 300000000, },
+	{ HI3519_FIXED_400M, "400m", NULL, 0, 400000000, },
+};
+
+static const char *const fmc_mux_p[] = {
+		"24m", "75m", "125m", "150m", "200m", "250m", "300m", "400m", };
+static u32 fmc_mux_table[] = {0, 1, 2, 3, 4, 5, 6, 7};
+
+static const struct hisi_mux_clock hi3519_mux_clks[] = {
+	{ HI3519_FMC_MUX, "fmc_mux", fmc_mux_p, ARRAY_SIZE(fmc_mux_p),
+		CLK_SET_RATE_PARENT, 0xc0, 2, 3, 0, fmc_mux_table, },
+};
+
+static const struct hisi_gate_clock hi3519_gate_clks[] = {
+	{ HI3519_FMC_CLK, "clk_fmc", "fmc_mux",
+		CLK_SET_RATE_PARENT, 0xc0, 1, 0, },
+	{ HI3519_UART0_CLK, "clk_uart0", "24m",
+		CLK_SET_RATE_PARENT, 0xe4, 20, 0, },
+	{ HI3519_UART1_CLK, "clk_uart1", "24m",
+		CLK_SET_RATE_PARENT, 0xe4, 21, 0, },
+	{ HI3519_UART2_CLK, "clk_uart2", "24m",
+		CLK_SET_RATE_PARENT, 0xe4, 22, 0, },
+	{ HI3519_UART3_CLK, "clk_uart3", "24m",
+		CLK_SET_RATE_PARENT, 0xe4, 23, 0, },
+	{ HI3519_UART4_CLK, "clk_uart4", "24m",
+		CLK_SET_RATE_PARENT, 0xe4, 24, 0, },
+	{ HI3519_SPI0_CLK, "clk_spi0", "50m",
+		CLK_SET_RATE_PARENT, 0xe4, 16, 0, },
+	{ HI3519_SPI1_CLK, "clk_spi1", "50m",
+		CLK_SET_RATE_PARENT, 0xe4, 17, 0, },
+	{ HI3519_SPI2_CLK, "clk_spi2", "50m",
+		CLK_SET_RATE_PARENT, 0xe4, 18, 0, },
+};
+
+static int hi3519_clk_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct hisi_clock_data *clk_data;
+	struct hisi_reset_controller *rstc;
+
+	rstc = hisi_reset_init(np);
+	if (!rstc)
+		return -ENOMEM;
+
+	clk_data = hisi_clk_init(np, HI3519_NR_CLKS);
+	if (!clk_data) {
+		hisi_reset_exit(rstc);
+		return -ENODEV;
+	}
+
+	hisi_clk_register_fixed_rate(hi3519_fixed_rate_clks,
+				     ARRAY_SIZE(hi3519_fixed_rate_clks),
+				     clk_data);
+	hisi_clk_register_mux(hi3519_mux_clks, ARRAY_SIZE(hi3519_mux_clks),
+					clk_data);
+	hisi_clk_register_gate(hi3519_gate_clks,
+			ARRAY_SIZE(hi3519_gate_clks), clk_data);
+
+	return 0;
+}
+
+static const struct of_device_id hi3519_clk_match_table[] = {
+	{ .compatible = "hisilicon,hi3519-crg" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, hi3519_clk_match_table);
+
+static struct platform_driver hi3519_clk_driver = {
+	.probe          = hi3519_clk_probe,
+	.driver         = {
+		.name   = "hi3519-clk",
+		.of_match_table = hi3519_clk_match_table,
+	},
+};
+
+static int __init hi3519_clk_init(void)
+{
+	return platform_driver_register(&hi3519_clk_driver);
+}
+core_initcall(hi3519_clk_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("HiSilicon Hi3519 Clock Driver");
diff --git a/include/dt-bindings/clock/hi3519-clock.h b/include/dt-bindings/clock/hi3519-clock.h
new file mode 100644
index 0000000..14f4d21
--- /dev/null
+++ b/include/dt-bindings/clock/hi3519-clock.h
@@ -0,0 +1,40 @@ 
+/*
+ * Copyright (c) 2015 HiSilicon Technologies Co., Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DTS_HI3519_CLOCK_H
+#define __DTS_HI3519_CLOCK_H
+
+#define HI3519_FMC_CLK			1
+#define HI3519_SPI0_CLK			2
+#define HI3519_SPI1_CLK			3
+#define HI3519_SPI2_CLK			4
+#define HI3519_UART0_CLK		5
+#define HI3519_UART1_CLK		6
+#define HI3519_UART2_CLK		7
+#define HI3519_UART3_CLK		8
+#define HI3519_UART4_CLK		9
+#define HI3519_PWM_CLK			10
+#define HI3519_DMA_CLK			11
+#define HI3519_IR_CLK			12
+#define HI3519_ETH_PHY_CLK		13
+#define HI3519_ETH_MAC_CLK		14
+#define HI3519_ETH_MACIF_CLK		15
+#define HI3519_USB2_BUS_CLK		16
+#define HI3519_USB2_PORT_CLK		17
+#define HI3519_USB3_CLK			18
+
+#endif	/* __DTS_HI3519_CLOCK_H */