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SubjectRe: [PATCH v2 1/1] gpio: nct6116d: add new driver for several Nuvoton super io chips
On Mon, Jul 4, 2022 at 3:06 PM Henning Schild
<henning.schild@siemens.com> wrote:
>
> This patch adds gpio support for several Nuvoton NCTXXX chips. These
> Super-I/O chips offer multiple functions of which several already have
> drivers in the kernel, i.e. hwmon and watchdog.
>
> Signed-off-by: Henning Schild <henning.schild@siemens.com>
> ---
> drivers/gpio/Kconfig | 9 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-nct6116d.c | 412 +++++++++++++++++++++++++++++++++++
> 3 files changed, 422 insertions(+)
> create mode 100644 drivers/gpio/gpio-nct6116d.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b01961999ced..40f1494b1adc 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -457,6 +457,15 @@ config GPIO_MXS
> select GPIO_GENERIC
> select GENERIC_IRQ_CHIP
>
> +config GPIO_NCT6116D
> + tristate "Nuvoton Super-I/O GPIO support"
> + help
> + This option enables support for GPIOs found on Nuvoton Super-I/O
> + chips NCT5104D, NCT6106D, NCT6116D, NCT6122D.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called gpio-nct6116d.
> +
> config GPIO_OCTEON
> tristate "Cavium OCTEON GPIO"
> depends on CAVIUM_OCTEON_SOC
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 14352f6dfe8e..87f1b0a0cda2 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -107,6 +107,7 @@ obj-$(CONFIG_GPIO_MT7621) += gpio-mt7621.o
> obj-$(CONFIG_GPIO_MVEBU) += gpio-mvebu.o
> obj-$(CONFIG_GPIO_MXC) += gpio-mxc.o
> obj-$(CONFIG_GPIO_MXS) += gpio-mxs.o
> +obj-$(CONFIG_GPIO_NCT6116D) += gpio-nct6116d.o
> obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o
> obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
> obj-$(CONFIG_GPIO_PALMAS) += gpio-palmas.o
> diff --git a/drivers/gpio/gpio-nct6116d.c b/drivers/gpio/gpio-nct6116d.c
> new file mode 100644
> index 000000000000..6c277636c773
> --- /dev/null
> +++ b/drivers/gpio/gpio-nct6116d.c
> @@ -0,0 +1,412 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * GPIO driver for Nuvoton Super-I/O chips NCT5104D, NCT6106D, NCT6116D, NCT6122D
> + *
> + * Authors:
> + * Tasanakorn Phaipool <tasanakorn@gmail.com>
> + * Sheng-Yuan Huang <syhuang3@nuvoton.com>
> + * Kuan-Wei Ho <cwho@nuvoton.com>
> + * Henning Schild <henning.schild@siemens.com>
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/gpio/driver.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +/*
> + * Super-I/O registers
> + */
> +#define SIO_LDSEL 0x07 /* Logical device select */
> +#define SIO_CHIPID 0x20 /* Chaip ID (2 bytes) */
> +#define SIO_GPIO_ENABLE 0x30 /* GPIO enable */
> +
> +#define SIO_LD_GPIO 0x07 /* GPIO logical device */
> +#define SIO_UNLOCK_KEY 0x87 /* Key to enable Super-I/O */
> +#define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
> +
> +#define SIO_ID_MASK GENMASK(15, 4)
> +#define SIO_NCT5104D_ID 0x1061
> +#define SIO_NCT6106D_ID 0xC452
> +#define SIO_NCT6116D_ID 0xD282
> +#define SIO_NCT6122D_ID 0xD2A3
> +
> +enum chips {
> + nct5104d,
> + nct6106d,
> + nct6116d,
> + nct6122d,
> +};
> +
> +static const char * const nct6116d_names[] = {
> + [nct5104d] = "nct5104d",
> + [nct6106d] = "nct6106d",
> + [nct6116d] = "nct6116d",
> + [nct6122d] = "nct6122d",
> +};
> +
> +struct nct6116d_sio {
> + int addr;
> + enum chips type;
> +};
> +
> +struct nct6116d_gpio_bank {
> + struct gpio_chip chip;
> + unsigned int regbase;
> + struct nct6116d_gpio_data *data;
> +};
> +
> +struct nct6116d_gpio_data {
> + struct nct6116d_sio *sio;
> + int nr_bank;
> + struct nct6116d_gpio_bank *bank;
> +};
> +
> +/*
> + * Super-I/O functions.
> + */
> +
> +static inline int superio_inb(int base, int reg)
> +{
> + outb(reg, base);
> + return inb(base + 1);
> +}
> +
> +static int superio_inw(int base, int reg)
> +{
> + int val;
> +
> + outb(reg++, base);
> + val = inb(base + 1) << 8;
> + outb(reg, base);
> + val |= inb(base + 1);
> +
> + return val;
> +}
> +
> +static inline void superio_outb(int base, int reg, int val)
> +{
> + outb(reg, base);
> + outb(val, base + 1);
> +}
> +
> +static inline int superio_enter(int base)
> +{
> + /* Don't step on other drivers' I/O space by accident. */
> + if (!request_muxed_region(base, 2, KBUILD_MODNAME)) {
> + pr_err("I/O address 0x%04x already in use\n", base);
> + return -EBUSY;
> + }
> +
> + /* According to the datasheet the key must be send twice. */
> + outb(SIO_UNLOCK_KEY, base);
> + outb(SIO_UNLOCK_KEY, base);
> +
> + return 0;
> +}
> +
> +static inline void superio_select(int base, int ld)
> +{
> + outb(SIO_LDSEL, base);
> + outb(ld, base + 1);
> +}
> +
> +static inline void superio_exit(int base)
> +{
> + outb(SIO_LOCK_KEY, base);
> + release_region(base, 2);
> +}
> +
> +/*
> + * GPIO chip.
> + */
> +
> +#define gpio_dir(base) ((base) + 0)
> +#define gpio_data(base) ((base) + 1)
> +
> +static inline void *nct6116d_to_gpio_bank(struct gpio_chip *chip)
> +{
> + return container_of(chip, struct nct6116d_gpio_bank, chip);
> +}
> +
> +static int nct6116d_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
> +{
> + struct nct6116d_gpio_bank *bank = nct6116d_to_gpio_bank(chip);
> + struct nct6116d_sio *sio = bank->data->sio;
> + int err;
> + u8 dir;
> +
> + err = superio_enter(sio->addr);
> + if (err)
> + return err;
> + superio_select(sio->addr, SIO_LD_GPIO);
> +
> + dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
> +
> + superio_exit(sio->addr);
> +
> + if (dir & 1 << offset)
> + return GPIO_LINE_DIRECTION_OUT;
> +
> + return GPIO_LINE_DIRECTION_IN;
> +}
> +
> +static int nct6116d_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
> +{
> + struct nct6116d_gpio_bank *bank = nct6116d_to_gpio_bank(chip);
> + struct nct6116d_sio *sio = bank->data->sio;
> + int err;
> + u8 dir;
> +
> + err = superio_enter(sio->addr);
> + if (err)
> + return err;
> + superio_select(sio->addr, SIO_LD_GPIO);
> +
> + dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
> + dir |= BIT(offset);
> + superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
> +
> + superio_exit(sio->addr);
> +
> + return 0;
> +}
> +
> +static int nct6116d_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> + struct nct6116d_gpio_bank *bank = nct6116d_to_gpio_bank(chip);
> + struct nct6116d_sio *sio = bank->data->sio;
> + int err;
> + u8 data;
> +
> + err = superio_enter(sio->addr);
> + if (err)
> + return err;
> + superio_select(sio->addr, SIO_LD_GPIO);
> +
> + data = superio_inb(sio->addr, gpio_data(bank->regbase));
> +
> + superio_exit(sio->addr);
> +
> + return !!(data & BIT(offset));
> +}
> +
> +static int nct6116d_gpio_direction_out(struct gpio_chip *chip,
> + unsigned int offset, int value)
> +{
> + struct nct6116d_gpio_bank *bank = nct6116d_to_gpio_bank(chip);
> + struct nct6116d_sio *sio = bank->data->sio;
> + u8 dir, data_out;
> + int err;
> +
> + err = superio_enter(sio->addr);
> + if (err)
> + return err;
> + superio_select(sio->addr, SIO_LD_GPIO);
> +
> + data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
> + if (value)
> + data_out |= BIT(offset);
> + else
> + data_out &= ~BIT(offset);
> + superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
> +
> + dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
> + dir &= ~BIT(offset);
> + superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
> +
> + superio_exit(sio->addr);
> +
> + return 0;
> +}
> +
> +static void nct6116d_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
> +{
> + struct nct6116d_gpio_bank *bank = nct6116d_to_gpio_bank(chip);
> + struct nct6116d_sio *sio = bank->data->sio;
> + u8 data_out;
> + int err;
> +
> + err = superio_enter(sio->addr);
> + if (err)
> + return;
> + superio_select(sio->addr, SIO_LD_GPIO);
> +
> + data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
> + if (value)
> + data_out |= BIT(offset);
> + else
> + data_out &= ~BIT(offset);
> + superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
> +
> + superio_exit(sio->addr);
> +}
> +
> +#define NCT6116D_GPIO_BANK(_base, _ngpio, _regbase, _label) \
> + { \
> + .chip = { \
> + .label = _label, \
> + .owner = THIS_MODULE, \
> + .get_direction = nct6116d_gpio_get_direction, \
> + .direction_input = nct6116d_gpio_direction_in, \
> + .get = nct6116d_gpio_get, \
> + .direction_output = nct6116d_gpio_direction_out, \
> + .set = nct6116d_gpio_set, \
> + .base = _base, \
> + .ngpio = _ngpio, \
> + .can_sleep = false, \
> + }, \
> + .regbase = _regbase, \
> + }
> +
> +static struct nct6116d_gpio_bank nct6116d_gpio_bank[] = {
> + NCT6116D_GPIO_BANK(0, 8, 0xE0, KBUILD_MODNAME "-0"),
> + NCT6116D_GPIO_BANK(10, 8, 0xE4, KBUILD_MODNAME "-1"),
> + NCT6116D_GPIO_BANK(20, 8, 0xE8, KBUILD_MODNAME "-2"),
> + NCT6116D_GPIO_BANK(30, 8, 0xEC, KBUILD_MODNAME "-3"),
> + NCT6116D_GPIO_BANK(40, 8, 0xF0, KBUILD_MODNAME "-4"),
> +};
> +
> +/*
> + * Platform device and driver.
> + */
> +
> +static int nct6116d_gpio_probe(struct platform_device *pdev)
> +{
> + struct nct6116d_sio *sio = pdev->dev.platform_data;
> + struct nct6116d_gpio_data *data;
> + int err;
> + int i;
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->nr_bank = ARRAY_SIZE(nct6116d_gpio_bank);
> + data->bank = nct6116d_gpio_bank;
> + data->sio = sio;
> +
> + platform_set_drvdata(pdev, data);
> +
> + /* For each GPIO bank, register a GPIO chip. */
> + for (i = 0; i < data->nr_bank; i++) {
> + struct nct6116d_gpio_bank *bank = &data->bank[i];
> +
> + bank->chip.parent = &pdev->dev;
> + bank->data = data;
> +
> + err = devm_gpiochip_add_data(&pdev->dev, &bank->chip, bank);
> + if (err)
> + return dev_err_probe(&pdev->dev, err,
> + "Failed to register gpiochip %d\n", i);
> + }
> +
> + return 0;
> +}
> +
> +static int __init nct6116d_find(int addr, struct nct6116d_sio *sio)
> +{
> + u16 devid;
> + int err;
> +
> + err = superio_enter(addr);
> + if (err)
> + return err;
> +
> + devid = superio_inw(addr, SIO_CHIPID);
> + superio_exit(addr);
> + switch (devid & SIO_ID_MASK) {
> + case SIO_NCT5104D_ID & SIO_ID_MASK:
> + sio->type = nct5104d;
> + break;
> + case SIO_NCT6106D_ID & SIO_ID_MASK:
> + sio->type = nct6106d;
> + break;
> + case SIO_NCT6116D_ID & SIO_ID_MASK:
> + sio->type = nct6116d;
> + break;
> + case SIO_NCT6122D_ID & SIO_ID_MASK:
> + sio->type = nct6122d;
> + break;
> + default:
> + pr_info("Unsupported device 0x%04x\n", devid);
> + return -ENODEV;
> + }
> + sio->addr = addr;
> +
> + pr_info("Found %s at 0x%x chip id 0x%04x\n",
> + nct6116d_names[sio->type], addr, devid);
> + return 0;
> +}
> +
> +static struct platform_device *nct6116d_gpio_pdev;
> +
> +static int __init
> +nct6116d_gpio_device_add(const struct nct6116d_sio *sio)
> +{
> + int err;
> +
> + nct6116d_gpio_pdev = platform_device_alloc(KBUILD_MODNAME, -1);
> + if (!nct6116d_gpio_pdev)
> + return -ENOMEM;
> +
> + err = platform_device_add_data(nct6116d_gpio_pdev, sio, sizeof(*sio));
> + if (err) {
> + pr_err("Platform data allocation failed\n");
> + goto err;
> + }
> +
> + err = platform_device_add(nct6116d_gpio_pdev);
> + if (err) {
> + pr_err("Device addition failed\n");
> + goto err;
> + }
> +
> + return 0;
> +
> +err:
> + platform_device_put(nct6116d_gpio_pdev);
> +
> + return err;
> +}
> +
> +static struct platform_driver nct6116d_gpio_driver = {
> + .driver = {
> + .name = KBUILD_MODNAME,
> + },
> + .probe = nct6116d_gpio_probe,
> +};
> +
> +static int __init nct6116d_gpio_init(void)
> +{
> + struct nct6116d_sio sio;
> + int err;
> +
> + if (nct6116d_find(0x2e, &sio) &&
> + nct6116d_find(0x4e, &sio))
> + return -ENODEV;
> +
> + err = platform_driver_register(&nct6116d_gpio_driver);
> + if (!err) {
> + err = nct6116d_gpio_device_add(&sio);
> + if (err)
> + platform_driver_unregister(&nct6116d_gpio_driver);
> + }
> +
> + return err;
> +}
> +subsys_initcall(nct6116d_gpio_init);
> +

I need some explanation on this part. You load the module and it
creates and registers the platform device? This is not how it's done
in the kernel. It's a platform device so it shouldn't be dynamically
probed for in the module's init function. It should be defined in
device-tree or ACPI. What platform are you using it on? Manual
creation of platform devices is limited to a small set of special
cases.

Bart

> +static void __exit nct6116d_gpio_exit(void)
> +{
> + platform_device_unregister(nct6116d_gpio_pdev);
> + platform_driver_unregister(&nct6116d_gpio_driver);
> +}
> +module_exit(nct6116d_gpio_exit);
> +
> +MODULE_DESCRIPTION("GPIO driver for Nuvoton Super-I/O chips NCT5104D, NCT6106D, NCT6116D, NCT6122D");
> +MODULE_AUTHOR("Tasanakorn Phaipool <tasanakorn@gmail.com>");
> +MODULE_LICENSE("GPL");
> --
> 2.35.1
>

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