2015-06-02 16:49:22

by Cyrille Pitchen

[permalink] [raw]
Subject: [PATCH 0/2] clk: at91: add new driver for Flexcom

ChangeLog

v1:
This series of patches introduces a new driver for the Atmel Flexcom.

Cyrille Pitchen (2):
clk: at91: add a new compatible string for Flexcom in the DT
documentation
clk: at91: add Flexcom clock

.../devicetree/bindings/clock/at91-clock.txt | 20 +++
arch/arm/mach-at91/Kconfig | 3 +
drivers/clk/at91/Makefile | 1 +
drivers/clk/at91/clk-flexcom.c | 160 +++++++++++++++++++++
4 files changed, 184 insertions(+)
create mode 100644 drivers/clk/at91/clk-flexcom.c

--
1.8.2.2


2015-06-02 16:49:57

by Cyrille Pitchen

[permalink] [raw]
Subject: [PATCH 1/2] clk: at91: add a new compatible string for Flexcom in the DT documentation

This patches documents the new bindings for the Flexcom clock, which will
be introduced by Atmel sama5d2x chips.

Signed-off-by: Cyrille Pitchen <[email protected]>
---
.../devicetree/bindings/clock/at91-clock.txt | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 7a4d492..df4f40b 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -77,6 +77,9 @@ Required properties:
"atmel,sama5d4-clk-h32mx":
at91 h32mx clock

+ "atmel,sama5d2-flexcom":
+ at91 flexcom 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).
@@ -461,3 +464,20 @@ For example:
compatible = "atmel,sama5d4-clk-h32mx";
clocks = <&mck>;
};
+
+Required properties for flexcom clock:
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : shall be the Flexcom peripheral clock from PMC.
+- reg : shall be the range for Flexcom dedicated I/O registers (without USART,
+ TWI or SPI registers).
+- atmel,flexcom-mode : shall be a string value among { "spi", "usart", "i2c",
+ "twi" }. "i2c" and "twi" are synonymous.
+
+For example:
+ flx0: flexcom@f8034000 {
+ compatible = "atmel,sama5d2-flexcom";
+ #clock-cells = <0>;
+ reg = <0xf8034000 0x200>;
+ clocks = <&flx0_clk>;
+ atmel,flexcom-mode = "spi";
+ };
--
1.8.2.2

2015-06-02 16:50:27

by Cyrille Pitchen

[permalink] [raw]
Subject: [PATCH 2/2] clk: at91: add Flexcom clock

Signed-off-by: Cyrille Pitchen <[email protected]>

This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which
integrates one SPI controller, one I2C controller and one USART. Only one
function can be enabled at a time. This driver selects the function once for
all, when the Flexcom is probed, according to the value of the new
"atmel,flexcom-mode" device tree property.

This driver has chosen to present the Flexcom to the system as a clock so the
implementation is seamless for the existing Atmel SPI, I2C and USART drivers.

Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and USART
drivers take advantage of this new feature.

Conflicts:
drivers/clk/at91/Makefile
---
arch/arm/mach-at91/Kconfig | 3 +
drivers/clk/at91/Makefile | 1 +
drivers/clk/at91/clk-flexcom.c | 160 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 164 insertions(+)
create mode 100644 drivers/clk/at91/clk-flexcom.c

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index fd95f34..8ce9b73 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -90,6 +90,9 @@ config HAVE_AT91_SMD
config HAVE_AT91_H32MX
bool

+config HAVE_AT91_FLEXCOM
+ bool
+
config SOC_SAM_V4_V5
bool

diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 89a48a7..74711b8 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -10,3 +10,4 @@ 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
+obj-$(CONFIG_HAVE_AT91_FLEXCOM) += clk-flexcom.o
diff --git a/drivers/clk/at91/clk-flexcom.c b/drivers/clk/at91/clk-flexcom.c
new file mode 100644
index 0000000..ce39093
--- /dev/null
+++ b/drivers/clk/at91/clk-flexcom.c
@@ -0,0 +1,160 @@
+/*
+ * Driver for Atmel AT91 Flexcom
+ *
+ * Copyright (C) 2014 Atmel Corporation
+ *
+ * Author: Cyrille Pitchen <[email protected]>
+ *
+ * Based on drivers/clk/clk-axi-clkgen.c
+ *
+ * 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/platform_device.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/module.h>
+
+
+#define FX_MR 0x0
+#define FX_RHR 0x10
+#define FX_THR 0x20
+#define FX_VERSION 0xfc
+
+#define FX_MR_NO_COM 0
+#define FX_MR_USART 1
+#define FX_MR_SPI 2
+#define FX_MR_TWI 3
+
+struct clk_flexcom {
+ struct clk_hw hw;
+ struct device *dev;
+ u8 __iomem *base;
+ u32 mr;
+ bool show_once;
+};
+
+#define to_clk_flexcom(_hw) container_of(_hw, struct clk_flexcom, hw)
+
+
+static int at91_flexcom_enable(struct clk_hw *hw)
+{
+ struct clk_flexcom *dev = to_clk_flexcom(hw);
+ u32 version;
+
+ if (!dev->show_once) {
+ dev->show_once = true;
+ version = __raw_readl(dev->base + FX_VERSION);
+ dev_info(dev->dev, "version: %#x\n", version);
+ }
+
+ __raw_writel(dev->mr, dev->base + FX_MR);
+ return 0;
+}
+
+static void at91_flexcom_disable(struct clk_hw *hw)
+{
+ struct clk_flexcom *dev = to_clk_flexcom(hw);
+
+ __raw_writel(FX_MR_NO_COM, dev->base + FX_MR);
+}
+
+static const struct clk_ops at91_flexcom_ops = {
+ .enable = at91_flexcom_enable,
+ .disable = at91_flexcom_disable,
+};
+
+static int at91_flexcom_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct clk_flexcom *dev;
+ struct resource *mem;
+ const char *parent_name, *clk_name, *mode;
+ struct clk *clk;
+ struct clk_init_data init;
+ u32 mr = FX_MR_NO_COM;
+ int err;
+
+ if (!np)
+ return -ENODEV;
+
+ err = of_property_read_string(np, "atmel,flexcom-mode", &mode);
+ if (err)
+ return err;
+
+ if (!strcmp(mode, "usart"))
+ mr = FX_MR_USART;
+ else if (!strcmp(mode, "spi"))
+ mr = FX_MR_SPI;
+ else if (!strcmp(mode, "twi") || !strcmp(mode, "i2c"))
+ mr = FX_MR_TWI;
+ else
+ return -EINVAL;
+
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev->base = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(dev->base))
+ return PTR_ERR(dev->base);
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ if (!parent_name)
+ return -EINVAL;
+
+ clk_name = np->name;
+ of_property_read_string(np, "clock-output-names", &clk_name);
+
+ init.name = clk_name;
+ init.ops = &at91_flexcom_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ dev->hw.init = &init;
+ dev->dev = &pdev->dev;
+ dev->mr = mr;
+ platform_set_drvdata(pdev, dev);
+
+ clk = devm_clk_register(&pdev->dev, &dev->hw);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ return of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static int at91_flexcom_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+
+ return 0;
+}
+
+static const struct of_device_id at91_flexcom_dt_ids[] = {
+ { .compatible = "atmel,sama5d2-flexcom" },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, at91_flexcom_dt_ids);
+
+static struct platform_driver at91_flexcom_driver = {
+ .driver = {
+ .name = "at91_flexcom",
+ .of_match_table = of_match_ptr(at91_flexcom_dt_ids),
+ },
+ .probe = at91_flexcom_probe,
+ .remove = at91_flexcom_remove,
+};
+module_platform_driver(at91_flexcom_driver);
+
+MODULE_ALIAS("platform:at91_flexcom");
+MODULE_DESCRIPTION("Atmel AT91 Flexcom driver");
+MODULE_AUTHOR("Cyrille Pitchen <[email protected]>");
+MODULE_LICENSE("GPL v2");
+
--
1.8.2.2

2015-06-02 16:58:46

by Cyrille Pitchen

[permalink] [raw]
Subject: Re: [PATCH 2/2] clk: at91: add Flexcom clock

Le 02/06/2015 18:49, Cyrille Pitchen a ?crit :
> Signed-off-by: Cyrille Pitchen <[email protected]>
>
> This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which
> integrates one SPI controller, one I2C controller and one USART. Only one
> function can be enabled at a time. This driver selects the function once for
> all, when the Flexcom is probed, according to the value of the new
> "atmel,flexcom-mode" device tree property.
>
> This driver has chosen to present the Flexcom to the system as a clock so the
> implementation is seamless for the existing Atmel SPI, I2C and USART drivers.
>
> Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and USART
> drivers take advantage of this new feature.
>
> Conflicts:
> drivers/clk/at91/Makefile
issue with the commit message: sending a new series

Cyrille

> ---
> arch/arm/mach-at91/Kconfig | 3 +
> drivers/clk/at91/Makefile | 1 +
> drivers/clk/at91/clk-flexcom.c | 160 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 164 insertions(+)
> create mode 100644 drivers/clk/at91/clk-flexcom.c
>
> diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
> index fd95f34..8ce9b73 100644
> --- a/arch/arm/mach-at91/Kconfig
> +++ b/arch/arm/mach-at91/Kconfig
> @@ -90,6 +90,9 @@ config HAVE_AT91_SMD
> config HAVE_AT91_H32MX
> bool
>
> +config HAVE_AT91_FLEXCOM
> + bool
> +
> config SOC_SAM_V4_V5
> bool
>
> diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
> index 89a48a7..74711b8 100644
> --- a/drivers/clk/at91/Makefile
> +++ b/drivers/clk/at91/Makefile
> @@ -10,3 +10,4 @@ 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
> +obj-$(CONFIG_HAVE_AT91_FLEXCOM) += clk-flexcom.o
> diff --git a/drivers/clk/at91/clk-flexcom.c b/drivers/clk/at91/clk-flexcom.c
> new file mode 100644
> index 0000000..ce39093
> --- /dev/null
> +++ b/drivers/clk/at91/clk-flexcom.c
> @@ -0,0 +1,160 @@
> +/*
> + * Driver for Atmel AT91 Flexcom
> + *
> + * Copyright (C) 2014 Atmel Corporation
> + *
> + * Author: Cyrille Pitchen <[email protected]>
> + *
> + * Based on drivers/clk/clk-axi-clkgen.c
> + *
> + * 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/platform_device.h>
> +#include <linux/clk-provider.h>
> +#include <linux/of.h>
> +#include <linux/module.h>
> +
> +
> +#define FX_MR 0x0
> +#define FX_RHR 0x10
> +#define FX_THR 0x20
> +#define FX_VERSION 0xfc
> +
> +#define FX_MR_NO_COM 0
> +#define FX_MR_USART 1
> +#define FX_MR_SPI 2
> +#define FX_MR_TWI 3
> +
> +struct clk_flexcom {
> + struct clk_hw hw;
> + struct device *dev;
> + u8 __iomem *base;
> + u32 mr;
> + bool show_once;
> +};
> +
> +#define to_clk_flexcom(_hw) container_of(_hw, struct clk_flexcom, hw)
> +
> +
> +static int at91_flexcom_enable(struct clk_hw *hw)
> +{
> + struct clk_flexcom *dev = to_clk_flexcom(hw);
> + u32 version;
> +
> + if (!dev->show_once) {
> + dev->show_once = true;
> + version = __raw_readl(dev->base + FX_VERSION);
> + dev_info(dev->dev, "version: %#x\n", version);
> + }
> +
> + __raw_writel(dev->mr, dev->base + FX_MR);
> + return 0;
> +}
> +
> +static void at91_flexcom_disable(struct clk_hw *hw)
> +{
> + struct clk_flexcom *dev = to_clk_flexcom(hw);
> +
> + __raw_writel(FX_MR_NO_COM, dev->base + FX_MR);
> +}
> +
> +static const struct clk_ops at91_flexcom_ops = {
> + .enable = at91_flexcom_enable,
> + .disable = at91_flexcom_disable,
> +};
> +
> +static int at91_flexcom_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct clk_flexcom *dev;
> + struct resource *mem;
> + const char *parent_name, *clk_name, *mode;
> + struct clk *clk;
> + struct clk_init_data init;
> + u32 mr = FX_MR_NO_COM;
> + int err;
> +
> + if (!np)
> + return -ENODEV;
> +
> + err = of_property_read_string(np, "atmel,flexcom-mode", &mode);
> + if (err)
> + return err;
> +
> + if (!strcmp(mode, "usart"))
> + mr = FX_MR_USART;
> + else if (!strcmp(mode, "spi"))
> + mr = FX_MR_SPI;
> + else if (!strcmp(mode, "twi") || !strcmp(mode, "i2c"))
> + mr = FX_MR_TWI;
> + else
> + return -EINVAL;
> +
> + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> + if (!dev)
> + return -ENOMEM;
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + dev->base = devm_ioremap_resource(&pdev->dev, mem);
> + if (IS_ERR(dev->base))
> + return PTR_ERR(dev->base);
> +
> + parent_name = of_clk_get_parent_name(np, 0);
> + if (!parent_name)
> + return -EINVAL;
> +
> + clk_name = np->name;
> + of_property_read_string(np, "clock-output-names", &clk_name);
> +
> + init.name = clk_name;
> + init.ops = &at91_flexcom_ops;
> + init.flags = 0;
> + init.parent_names = &parent_name;
> + init.num_parents = 1;
> +
> + dev->hw.init = &init;
> + dev->dev = &pdev->dev;
> + dev->mr = mr;
> + platform_set_drvdata(pdev, dev);
> +
> + clk = devm_clk_register(&pdev->dev, &dev->hw);
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + return of_clk_add_provider(np, of_clk_src_simple_get, clk);
> +}
> +
> +static int at91_flexcom_remove(struct platform_device *pdev)
> +{
> + of_clk_del_provider(pdev->dev.of_node);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id at91_flexcom_dt_ids[] = {
> + { .compatible = "atmel,sama5d2-flexcom" },
> + { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, at91_flexcom_dt_ids);
> +
> +static struct platform_driver at91_flexcom_driver = {
> + .driver = {
> + .name = "at91_flexcom",
> + .of_match_table = of_match_ptr(at91_flexcom_dt_ids),
> + },
> + .probe = at91_flexcom_probe,
> + .remove = at91_flexcom_remove,
> +};
> +module_platform_driver(at91_flexcom_driver);
> +
> +MODULE_ALIAS("platform:at91_flexcom");
> +MODULE_DESCRIPTION("Atmel AT91 Flexcom driver");
> +MODULE_AUTHOR("Cyrille Pitchen <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> +
>

2015-06-02 19:49:22

by Sergei Shtylyov

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: at91: add a new compatible string for Flexcom in the DT documentation

Hello.

On 06/02/2015 07:49 PM, Cyrille Pitchen wrote:

> This patches documents the new bindings for the Flexcom clock, which will
> be introduced by Atmel sama5d2x chips.

> Signed-off-by: Cyrille Pitchen <[email protected]>
> ---
> .../devicetree/bindings/clock/at91-clock.txt | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)

> diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
> index 7a4d492..df4f40b 100644
> --- a/Documentation/devicetree/bindings/clock/at91-clock.txt
> +++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
[...]
> @@ -461,3 +464,20 @@ For example:
> compatible = "atmel,sama5d4-clk-h32mx";
> clocks = <&mck>;
> };
> +
> +Required properties for flexcom clock:
> +- #clock-cells : from common clock binding; shall be set to 0.
> +- clocks : shall be the Flexcom peripheral clock from PMC.
> +- reg : shall be the range for Flexcom dedicated I/O registers (without USART,
> + TWI or SPI registers).
> +- atmel,flexcom-mode : shall be a string value among { "spi", "usart", "i2c",
> + "twi" }. "i2c" and "twi" are synonymous.
> +
> +For example:
> + flx0: flexcom@f8034000 {

The ePAPR standard says: "The name of a node should be somewhat generic,
reflecting the function of the device and not its precise programming model."

[...]

WBR, Sergei