Re: [PATCH] clk: Add GPIO-controlled clock gate driver

On 8/13/23 19:51, Marek Vasut wrote:

Add driver which implements GPIO-controlled clock. The GPIO is used as a gate to enable/disable the clock. This matches linux clk-gpio.c driver, however this does not implement the GPIO mux part, which in U-Boot DM would be better fit in separate driver.

Signed-off-by: Marek Vasut marek.vasut+renesas@mailbox.org

Cc: Lukasz Majewski lukma@denx.de Cc: Sean Anderson seanga2@gmail.com

---

drivers/clk/Kconfig | 13 +++++++++ drivers/clk/Makefile | 1 + drivers/clk/clk-gpio.c | 66 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 80 insertions(+) create mode 100644 drivers/clk/clk-gpio.c

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 29859cdfa15..bfd23a99046 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -83,6 +83,19 @@ config CLK_COMPOSITE_CCF Enable this option if you want to (re-)use the Linux kernel's Common Clock Framework [CCF] composite code in U-Boot's clock driver.

+config CLK_GPIO

• bool "GPIO-controlled clock gate driver"
• depends on CLK
• help

•  Enable this option to add GPIO-controlled clock gate driver.
  

+config SPL_CLK_GPIO

• bool "GPIO-controlled clock gate driver in SPL"
• depends on SPL_CLK
• help

•  Enable this option to add GPIO-controlled clock gate driver
  

•  in U-Boot SPL.
  

• config CLK_BCM6345 bool "Clock controller driver for BCM6345" depends on CLK && ARCH_BMIPS

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index e22c8cf291f..26bf429acbc 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_factor.o obj-$(CONFIG_$(SPL_TPL_)CLK_CCF) += clk.o clk-divider.o clk-mux.o clk-gate.o obj-$(CONFIG_$(SPL_TPL_)CLK_CCF) += clk-fixed-factor.o obj-$(CONFIG_$(SPL_TPL_)CLK_COMPOSITE_CCF) += clk-composite.o +obj-$(CONFIG_$(SPL_TPL_)CLK_GPIO) += clk-gpio.o

obj-y += analogbits/ obj-y += imx/ diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c new file mode 100644 index 00000000000..26d795b9783 --- /dev/null +++ b/drivers/clk/clk-gpio.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • Copyright (C) 2023 Marek Vasut marek.vasut+renesas@mailbox.org
• */

+#include <asm/gpio.h> +#include <common.h> +#include <clk-uclass.h> +#include <dm.h>

+struct clk_gpio_priv {

• struct gpio_desc enable;

+};

+static int clk_gpio_enable(struct clk *clk) +{

• struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
• dm_gpio_set_value(&priv->enable, 1);
• return 0;

+}

+static int clk_gpio_disable(struct clk *clk) +{

• struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
• dm_gpio_set_value(&priv->enable, 0);
• return 0;

+}

+const struct clk_ops clk_gpio_ops = {

• .enable = clk_gpio_enable,
• .disable = clk_gpio_disable,

+};

+static int clk_gpio_probe(struct udevice *dev) +{

• struct clk_gpio_priv *priv = dev_get_priv(dev);
• return gpio_request_by_name(dev, "enable-gpios", 0,

• 		    &priv->enable, GPIOD_IS_OUT);
  

+}

+/*

• • When implementing clk-mux-clock, use gpio_request_list_by_name
• • and implement get_rate/set_rate/set_parent ops. This should be
• • in a separate driver and with separate Kconfig option to enable
• • that driver, since unlike Linux implementation, the U-Boot DM
• • integration would be orthogonal to this driver.
• */

+static const struct udevice_id clk_gpio_match[] = {

• { .compatible = "gpio-gate-clock" },
• { /* sentinel */ }

+};

+U_BOOT_DRIVER(gpio_gate_clock) = {

• .name = "gpio_clock",
• .id = UCLASS_CLK,
• .of_match = clk_gpio_match,
• .probe = clk_gpio_probe,
• .priv_auto = sizeof(struct clk_gpio_priv),
• .ops = &clk_gpio_ops,
• .flags = DM_FLAG_PRE_RELOC,

+};

Reviewed-by: Sean Anderson seanga2@gmail.com