Add a driver for Cadence I3C GPIO expander. Signed-off-by: Boris Brezillon <boris.brezil...@bootlin.com> --- drivers/gpio/Kconfig | 11 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-cdns-i3c.c | 380 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 392 insertions(+) create mode 100644 drivers/gpio/gpio-cdns-i3c.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 8dbb2280538d..87b7083179ff 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -862,6 +862,17 @@ config GPIO_TS4900 endmenu +menu "I3C GPIO expanders" + depends on I3C + +config GPIO_CDNS_I3C + tristate "Cadence I3C GPIO expander" + select GPIOLIB_IRQCHIP + help + Say yes here to enabled the driver for Cadence I3C GPIO expander. + +endmenu + menu "MFD GPIO expanders" config GPIO_ADP5520 diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index cccb0d40846c..22a7151fc565 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o +obj-$(CONFIG_GPIO_CDNS_I3C) += gpio-cdns-i3c.o obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o obj-$(CONFIG_GPIO_CRYSTAL_COVE) += gpio-crystalcove.o diff --git a/drivers/gpio/gpio-cdns-i3c.c b/drivers/gpio/gpio-cdns-i3c.c new file mode 100644 index 000000000000..58a903fabb0a --- /dev/null +++ b/drivers/gpio/gpio-cdns-i3c.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon <boris.brezil...@bootlin.com> + */ + +#include <linux/gpio/driver.h> +#include <linux/i3c/device.h> +#include <linux/module.h> + +#define OVR 0x0 +#define IVR 0x1 +#define DIR_MODE 0x2 +#define IMR 0x3 +#define ISR 0x4 +#define ITR(x) (0x5 + (x)) + +struct cdns_i3c_gpio { + struct gpio_chip gpioc; + struct irq_chip irqc; + struct i3c_device *i3cdev; + struct mutex irq_lock; + u8 dir; + u8 ovr; + u8 imr; + u8 itr[3]; +}; + +static struct cdns_i3c_gpio *gpioc_to_cdns_gpioc(struct gpio_chip *gpioc) +{ + return container_of(gpioc, struct cdns_i3c_gpio, gpioc); +} + +static int cdns_i3c_gpio_read_reg(struct cdns_i3c_gpio *gpioc, u8 reg, + u8 *val) +{ + struct i3c_priv_xfer xfers[] = { + { + .len = sizeof(reg), + .data.out = ®, + }, + { + .rnw = true, + .len = sizeof(*val), + .data.in = val, + }, + }; + + return i3c_device_do_priv_xfers(gpioc->i3cdev, xfers, + ARRAY_SIZE(xfers)); +} + +static int cdns_i3c_gpio_write_reg(struct cdns_i3c_gpio *gpioc, u8 reg, + u8 val) +{ + struct i3c_priv_xfer xfers[] = { + { + .len = sizeof(reg), + .data.out = ®, + }, + { + .len = sizeof(val), + .data.out = &val, + }, + }; + + return i3c_device_do_priv_xfers(gpioc->i3cdev, xfers, + ARRAY_SIZE(xfers)); +} + +static int cdns_i3c_gpio_get_direction(struct gpio_chip *g, unsigned offset) +{ + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); + + return gpioc->dir & BIT(offset); +} + +static void cdns_i3c_gpio_set_multiple(struct gpio_chip *g, + unsigned long *mask, + unsigned long *bits) +{ + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); + u8 newovr; + int ret; + + newovr = (gpioc->ovr & ~(*mask)) | (*bits & *mask); + if (newovr == gpioc->ovr) + return; + + ret = cdns_i3c_gpio_write_reg(gpioc, OVR, newovr); + if (!ret) + gpioc->ovr = newovr; +} + +static void cdns_i3c_gpio_set(struct gpio_chip *g, unsigned offset, int value) +{ + unsigned long mask = BIT(offset), bits = value ? BIT(offset) : 0; + + cdns_i3c_gpio_set_multiple(g, &mask, &bits); +} + +static int cdns_i3c_gpio_set_dir(struct cdns_i3c_gpio *gpioc, unsigned pin, + bool in) +{ + u8 newdir; + int ret; + + newdir = gpioc->dir; + if (in) + newdir |= BIT(pin); + else + newdir &= ~BIT(pin); + + if (newdir == gpioc->dir) + return 0; + + gpioc->dir = newdir; + ret = cdns_i3c_gpio_write_reg(gpioc, DIR_MODE, newdir); + if (!ret) + gpioc->dir = newdir; + + return ret; +} + +static int cdns_i3c_gpio_dir_input(struct gpio_chip *g, unsigned offset) +{ + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); + + return cdns_i3c_gpio_set_dir(gpioc, offset, true); +} + +static int cdns_i3c_gpio_dir_output(struct gpio_chip *g, unsigned offset, + int val) +{ + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); + + cdns_i3c_gpio_set(g, offset, val); + + return cdns_i3c_gpio_set_dir(gpioc, offset, true); +} + +static int cdns_i3c_gpio_get_multiple(struct gpio_chip *g, + unsigned long *mask, + unsigned long *bits) +{ + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); + int ret; + u8 ivr; + + ret = cdns_i3c_gpio_read_reg(gpioc, IVR, &ivr); + if (ret) + return ret; + + *bits = ivr & *mask & gpioc->dir; + *bits |= gpioc->ovr & *mask & ~gpioc->dir; + + return 0; +} + +static int cdns_i3c_gpio_get(struct gpio_chip *g, unsigned offset) +{ + unsigned long mask = BIT(offset), bits = 0; + int ret; + + ret = cdns_i3c_gpio_get_multiple(g, &mask, &bits); + if (ret) + return ret; + + return mask & bits; +} + +static void cdns_i3c_gpio_ibi_handler(struct i3c_device *i3cdev, + const struct i3c_ibi_payload *payload) +{ + struct cdns_i3c_gpio *gpioc = i3cdev_get_drvdata(i3cdev); + u8 isr = 0; + int i; + + cdns_i3c_gpio_read_reg(gpioc, ISR, &isr); + for (i = 0; i < 8; i++) { + unsigned int irq; + + if (!(BIT(i) & isr & gpioc->imr)) + continue; + + irq = irq_find_mapping(gpioc->gpioc.irq.domain, i); + handle_nested_irq(irq); + } +} + +static void cdns_i3c_gpio_irq_lock(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct cdns_i3c_gpio *gpioc = gpiochip_get_data(gc); + + mutex_lock(&gpioc->irq_lock); +} + +static void cdns_i3c_gpio_irq_sync_unlock(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct cdns_i3c_gpio *gpioc = gpiochip_get_data(gc); + int i; + + cdns_i3c_gpio_write_reg(gpioc, IMR, gpioc->imr); + for (i = 0; i < 3; i++) + cdns_i3c_gpio_write_reg(gpioc, ITR(i), gpioc->itr[i]); + + mutex_unlock(&gpioc->irq_lock); +} + +static void cdns_i3c_gpio_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct cdns_i3c_gpio *gpioc = gpiochip_get_data(gc); + + gpioc->imr |= BIT(data->hwirq); +} + +static void cdns_i3c_gpio_irq_mask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct cdns_i3c_gpio *gpioc = gpiochip_get_data(gc); + + gpioc->imr &= ~BIT(data->hwirq); +} + +static int cdns_i3c_gpio_irq_set_type(struct irq_data *data, unsigned type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct cdns_i3c_gpio *gpioc = gpiochip_get_data(gc); + + switch (type) { + case IRQ_TYPE_LEVEL_HIGH: + gpioc->itr[0] |= BIT(data->hwirq); + gpioc->itr[1] |= BIT(data->hwirq); + break; + + case IRQ_TYPE_LEVEL_LOW: + gpioc->itr[0] |= BIT(data->hwirq); + gpioc->itr[1] &= ~BIT(data->hwirq); + break; + + case IRQ_TYPE_EDGE_BOTH: + gpioc->itr[0] &= ~BIT(data->hwirq); + gpioc->itr[2] |= BIT(data->hwirq); + break; + + case IRQ_TYPE_EDGE_RISING: + gpioc->itr[0] &= ~BIT(data->hwirq); + gpioc->itr[1] |= BIT(data->hwirq); + gpioc->itr[2] &= ~BIT(data->hwirq); + break; + + case IRQ_TYPE_EDGE_FALLING: + gpioc->itr[0] &= ~BIT(data->hwirq); + gpioc->itr[1] &= ~BIT(data->hwirq); + gpioc->itr[2] &= ~BIT(data->hwirq); + break; + + default: + return -EINVAL; + } + + return 0; +} + +static int cdns_i3c_gpio_probe(struct i3c_device *i3cdev) +{ + struct cdns_i3c_gpio *gpioc; + struct device *parent = i3cdev_to_dev(i3cdev); + struct i3c_ibi_setup ibisetup = { + .max_payload_len = 2, + .num_slots = 1, + .handler = cdns_i3c_gpio_ibi_handler, + }; + int ret; + + gpioc = devm_kzalloc(parent, sizeof(*gpioc), GFP_KERNEL); + if (!gpioc) + return -ENOMEM; + + gpioc->i3cdev = i3cdev; + i3cdev_set_drvdata(i3cdev, gpioc); + + /* Mask all interrupts. */ + ret = cdns_i3c_gpio_write_reg(gpioc, IMR, 0); + if (ret) + return ret; + + /* + * Clear the ISR after reading it, not when the IBI is is Acked by the + * I3C master. This way we make sure we don't lose events. + */ + ret = cdns_i3c_gpio_write_reg(gpioc, ITR(3), 0xff); + if (ret) + return ret; + + ret = cdns_i3c_gpio_read_reg(gpioc, DIR_MODE, &gpioc->dir); + if (ret) + return ret; + + ret = cdns_i3c_gpio_read_reg(gpioc, OVR, &gpioc->ovr); + if (ret) + return ret; + + ret = i3c_device_request_ibi(i3cdev, &ibisetup); + if (ret) + return ret; + + gpioc->gpioc.label = dev_name(parent); + gpioc->gpioc.owner = THIS_MODULE; + gpioc->gpioc.parent = parent; + gpioc->gpioc.base = -1; + gpioc->gpioc.ngpio = 8; + gpioc->gpioc.can_sleep = true; + gpioc->gpioc.get_direction = cdns_i3c_gpio_get_direction; + gpioc->gpioc.direction_input = cdns_i3c_gpio_dir_input; + gpioc->gpioc.direction_output = cdns_i3c_gpio_dir_output; + gpioc->gpioc.get = cdns_i3c_gpio_get; + gpioc->gpioc.get_multiple = cdns_i3c_gpio_get_multiple; + gpioc->gpioc.set = cdns_i3c_gpio_set; + gpioc->gpioc.set_multiple = cdns_i3c_gpio_set_multiple; + + ret = devm_gpiochip_add_data(parent, &gpioc->gpioc, gpioc); + if (ret) + return ret; + + gpioc->irqc.name = dev_name(parent); + gpioc->irqc.parent_device = parent; + gpioc->irqc.irq_unmask = cdns_i3c_gpio_irq_unmask; + gpioc->irqc.irq_mask = cdns_i3c_gpio_irq_mask; + gpioc->irqc.irq_bus_lock = cdns_i3c_gpio_irq_lock; + gpioc->irqc.irq_bus_sync_unlock = cdns_i3c_gpio_irq_sync_unlock; + gpioc->irqc.irq_set_type = cdns_i3c_gpio_irq_set_type; + gpioc->irqc.flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND; + + ret = gpiochip_irqchip_add_nested(&gpioc->gpioc, &gpioc->irqc, 0, + handle_simple_irq, IRQ_TYPE_NONE); + if (ret) + goto err_free_ibi; + + ret = i3c_device_enable_ibi(i3cdev); + if (ret) + goto err_free_ibi; + + return 0; + +err_free_ibi: + i3c_device_free_ibi(i3cdev); + + return ret; +} + +static int cdns_i3c_gpio_remove(struct i3c_device *i3cdev) +{ + i3c_device_disable_ibi(i3cdev); + i3c_device_free_ibi(i3cdev); + + return 0; +} + +static const struct i3c_device_id cdns_i3c_gpio_ids[] = { + I3C_DEVICE(0x1c9, 0x0, NULL), + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(i3c, cdns_i3c_gpio_ids); + +static struct i3c_driver cdns_i3c_gpio = { + .driver.name = "cdns-i3c-gpio", + .id_table = cdns_i3c_gpio_ids, + .probe = cdns_i3c_gpio_probe, + .remove = cdns_i3c_gpio_remove, +}; +module_i3c_driver(cdns_i3c_gpio); + +MODULE_AUTHOR("Boris Brezillon <boris.brezil...@bootlin.com>"); +MODULE_DESCRIPTION("Driver for Cadence I3C GPIO expander"); +MODULE_LICENSE("GPL v2"); -- 2.14.1