[v5,2/2] gpio: ds4520: Add ADI DS4520 GPIO Expander Support
Commit Message
The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
It offers users a digitally programmable alternative
to hardware jumpers and mechanical switches that are
being used to control digital logic node.
Signed-off-by: Okan Sahin <okan.sahin@analog.com>
---
drivers/gpio/Kconfig | 11 ++++++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ds4520.c | 80 ++++++++++++++++++++++++++++++++++++++
3 files changed, 92 insertions(+)
create mode 100644 drivers/gpio/gpio-ds4520.c
Comments
On Thu, Jul 27, 2023 at 11:55 AM Okan Sahin <okan.sahin@analog.com> wrote:
> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
> It offers users a digitally programmable alternative
> to hardware jumpers and mechanical switches that are
> being used to control digital logic node.
>
> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
Too late to add review tags but just pointing out what a beauty
this driver is when using regmap GPIO. Total success!
Yours,
Linus Walleij
Hi,
> On Thu, Jul 27, 2023 at 11:55=E2=80=AFAM Okan Sahin <okan.sahin@analog.com>=
> wrote:
>
>> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
>> It offers users a digitally programmable alternative
>> to hardware jumpers and mechanical switches that are
>> being used to control digital logic node.
>>
>> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
>
> Too late to add review tags but just pointing out what a beauty
> this driver is when using regmap GPIO. Total success!
Mh somehow I'm always missing consumers of regmap GPIO.
Linus, Bartosz, what do you think about the patch below?
diff --git a/MAINTAINERS b/MAINTAINERS
index 20a0f7411efd..907f39825733 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8868,6 +8868,7 @@ R: Michael Walle <michael@walle.cc>
S: Maintained
F: drivers/gpio/gpio-regmap.c
F: include/linux/gpio/regmap.h
+K: (devm_)?gpio_regmap_(un)?register
GPIO SUBSYSTEM
M: Linus Walleij <linus.walleij@linaro.org>
-michael
On Wed, Aug 9, 2023 at 9:19 AM Michael Walle <mwalle@kernel.org> wrote:
> > On Thu, Jul 27, 2023 at 11:55=E2=80=AFAM Okan Sahin <okan.sahin@analog.com>=
> > wrote:
> >
> >> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
> >> It offers users a digitally programmable alternative
> >> to hardware jumpers and mechanical switches that are
> >> being used to control digital logic node.
> >>
> >> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
> >
> > Too late to add review tags but just pointing out what a beauty
> > this driver is when using regmap GPIO. Total success!
>
> Mh somehow I'm always missing consumers of regmap GPIO.
>
> Linus, Bartosz, what do you think about the patch below?
(...)
> +K: (devm_)?gpio_regmap_(un)?register
I never saw that globbing trick before, but makes perfect sense so:
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
@@ -1000,6 +1000,17 @@ config GPIO_ADNP
enough to represent all pins, but the driver will assume a
register layout for 64 pins (8 registers).
+config GPIO_DS4520
+ tristate "DS4520 I2C GPIO expander"
+ select REGMAP_I2C
+ select GPIO_REGMAP
+ help
+ GPIO driver for ADI DS4520 I2C-based GPIO expander.
+ Say yes here to enable the GPIO driver for the ADI DS4520 chip.
+
+ To compile this driver as a module, choose M here: the module will
+ be called gpio-ds4520.
+
config GPIO_GW_PLD
tristate "Gateworks PLD GPIO Expander"
depends on OF_GPIO
@@ -52,6 +52,7 @@ obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o
obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o
obj-$(CONFIG_GPIO_DLN2) += gpio-dln2.o
+obj-$(CONFIG_GPIO_DS4520) += gpio-ds4520.o
obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
obj-$(CONFIG_GPIO_EIC_SPRD) += gpio-eic-sprd.o
obj-$(CONFIG_GPIO_EM) += gpio-em.o
new file mode 100644
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023 Analog Devices, Inc.
+ * Driver for the DS4520 I/O Expander
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+#include <linux/i2c.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define DS4520_PULLUP0 0xF0
+#define DS4520_IO_CONTROL0 0xF2
+#define DS4520_IO_STATUS0 0xF8
+
+static const struct regmap_config ds4520_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int ds4520_gpio_probe(struct i2c_client *client)
+{
+ struct gpio_regmap_config config = { };
+ struct device *dev = &client->dev;
+ struct regmap *regmap;
+ u32 ngpio;
+ u32 base;
+ int ret;
+
+ ret = device_property_read_u32(dev, "reg", &base);
+ if (ret)
+ return dev_err_probe(dev, ret, "Missing 'reg' property.\n");
+
+ ret = device_property_read_u32(dev, "ngpios", &ngpio);
+ if (ret)
+ return dev_err_probe(dev, ret, "Missing 'ngpios' property.\n");
+
+ regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap),
+ "Failed to allocate register map\n");
+
+ config.regmap = regmap;
+ config.parent = dev;
+ config.ngpio = ngpio;
+
+ config.reg_dat_base = base + DS4520_IO_STATUS0;
+ config.reg_set_base = base + DS4520_PULLUP0;
+ config.reg_dir_out_base = base + DS4520_IO_CONTROL0;
+
+ return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
+}
+
+static const struct of_device_id ds4520_gpio_of_match_table[] = {
+ { .compatible = "adi,ds4520-gpio" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);
+
+static const struct i2c_device_id ds4520_gpio_id_table[] = {
+ { "ds4520-gpio" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);
+
+static struct i2c_driver ds4520_gpio_driver = {
+ .driver = {
+ .name = "ds4520-gpio",
+ .of_match_table = ds4520_gpio_of_match_table,
+ },
+ .probe = ds4520_gpio_probe,
+ .id_table = ds4520_gpio_id_table,
+};
+module_i2c_driver(ds4520_gpio_driver);
+
+MODULE_DESCRIPTION("DS4520 I/O Expander");
+MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");
+MODULE_LICENSE("GPL");