Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754040AbcKULIA (ORCPT ); Mon, 21 Nov 2016 06:08:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39056 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753240AbcKULH6 (ORCPT ); Mon, 21 Nov 2016 06:07:58 -0500 From: Benjamin Tissoires To: Ellen Wang , Antonio Borneo , David Barksdale , Jiri Kosina Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC] HID: cp2112: add IRQ chip handling Date: Mon, 21 Nov 2016 12:07:54 +0100 Message-Id: <1479726474-31532-1-git-send-email-benjamin.tissoires@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 21 Nov 2016 11:07:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8291 Lines: 323 The GPIO part doesn't provide interrupts when GPIO are toggled. So use a polling mechanism if someone requests a GPIO as an IRQ. Signed-off-by: Benjamin Tissoires --- I am currently running this patch in my local tree. It allows to attach a SMBus device completely on the CP2112, with a simple definition at the end of probe: { struct i2c_client *client; struct i2c_hid_platform_data pdata = { .hid_descriptor_address = 0x20, }; struct i2c_board_info synaptics_info = { I2C_BOARD_INFO("hid", 0x2c), .platform_data = &pdata, }; int irq = cp2112_allocate_irq(dev, 2); if (irq <= 0) { dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n"); goto err_sysfs_remove; } synaptics_info.irq = irq; irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW); hid_device_io_start(hdev); /* give time for the device to initialize */ msleep(500); client = i2c_new_device(&dev->adap, &synaptics_info); if (!client) hid_err(hdev, "failed allocating Synaptics device\n"); } I wonder if we want to consider this upstream, given that the driver is only used for development. Note: this patch applies on top of https://patchwork.kernel.org/patch/9439225/ Cheers, Benjamin drivers/hid/hid-cp2112.c | 205 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 202 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c index 60d3020..f31a778 100644 --- a/drivers/hid/hid-cp2112.c +++ b/drivers/hid/hid-cp2112.c @@ -24,6 +24,7 @@ * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf */ +#include #include #include #include @@ -168,6 +169,12 @@ struct cp2112_device { struct gpio_chip gc; u8 *in_out_buffer; spinlock_t lock; + + struct gpio_desc *desc[8]; + bool gpio_poll; + struct delayed_work gpio_poll_worker; + unsigned long irq_mask; + u8 gpio_prev_state; }; static int gpio_push_pull = 0xFF; @@ -233,7 +240,7 @@ static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value) spin_unlock_irqrestore(&dev->lock, flags); } -static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) +static int cp2112_gpio_get_all(struct gpio_chip *chip) { struct cp2112_device *dev = gpiochip_get_data(chip); struct hid_device *hdev = dev->hdev; @@ -252,7 +259,7 @@ static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) goto exit; } - ret = (buf[1] >> offset) & 1; + ret = buf[1]; exit: spin_unlock_irqrestore(&dev->lock, flags); @@ -260,6 +267,17 @@ static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) return ret; } +static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + int ret; + + ret = cp2112_gpio_get_all(chip); + if (ret < 0) + return ret; + + return (ret >> offset) & 1; +} + static int cp2112_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { @@ -1041,6 +1059,166 @@ static void chmod_sysfs_attrs(struct hid_device *hdev) } } +static void cp2112_gpio_irq_ack(struct irq_data *d) +{ +} + +static void cp2112_gpio_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + __clear_bit(d->hwirq, &dev->irq_mask); +} + +static void cp2112_gpio_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + __set_bit(d->hwirq, &dev->irq_mask); +} + +static void cp2112_gpio_poll_callback(struct work_struct *work) +{ + struct cp2112_device *dev = container_of(work, struct cp2112_device, + gpio_poll_worker.work); + struct irq_data *d; + u8 gpio_mask; + u8 virqs = (u8)dev->irq_mask; + u32 irq_type; + int irq, virq, ret; + + ret = cp2112_gpio_get_all(&dev->gc); + if (ret == -ENODEV) /* the hardware has been disconnected */ + return; + if (ret < 0) + goto exit; + + gpio_mask = ret; + + while (virqs) { + virq = ffs(virqs) - 1; + virqs &= ~BIT(virq); + + if (!dev->gc.to_irq) + break; + + irq = dev->gc.to_irq(&dev->gc, virq); + + d = irq_get_irq_data(irq); + if (!d) + continue; + + irq_type = irqd_get_trigger_type(d); + + if (gpio_mask & BIT(virq)) { + /* Level High */ + + if (irq_type & IRQ_TYPE_LEVEL_HIGH) + handle_nested_irq(irq); + + if ((irq_type & IRQ_TYPE_EDGE_RISING) && + !(dev->gpio_prev_state & BIT(virq))) + handle_nested_irq(irq); + } else { + /* Level Low */ + + if (irq_type & IRQ_TYPE_LEVEL_LOW) + handle_nested_irq(irq); + + if ((irq_type & IRQ_TYPE_EDGE_FALLING) && + (dev->gpio_prev_state & BIT(virq))) + handle_nested_irq(irq); + } + } + + dev->gpio_prev_state = gpio_mask; + +exit: + if (dev->gpio_poll) + schedule_delayed_work(&dev->gpio_poll_worker, 10); +} + + +static unsigned int cp2112_gpio_irq_startup(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback); + + cp2112_gpio_direction_input(gc, d->hwirq); + + if (!dev->gpio_poll) { + dev->gpio_poll = true; + schedule_delayed_work(&dev->gpio_poll_worker, 0); + } + + cp2112_gpio_irq_unmask(d); + return 0; +} + +static void cp2112_gpio_irq_shutdown(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + cancel_delayed_work_sync(&dev->gpio_poll_worker); +} + +static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type) +{ + return 0; +} + +static struct irq_chip cp2112_gpio_irqchip = { + .name = "cp2112-gpio", + .irq_startup = cp2112_gpio_irq_startup, + .irq_shutdown = cp2112_gpio_irq_shutdown, + .irq_ack = cp2112_gpio_irq_ack, + .irq_mask = cp2112_gpio_irq_mask, + .irq_unmask = cp2112_gpio_irq_unmask, + .irq_set_type = cp2112_gpio_irq_type, +}; + +static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev, + int pin) +{ + int ret; + + if (dev->desc[pin]) + return -EINVAL; + + dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin, + "HID/I2C:Event"); + if (IS_ERR(dev->desc[pin])) { + dev_err(dev->gc.parent, "Failed to request GPIO\n"); + return PTR_ERR(dev->desc[pin]); + } + + ret = gpiochip_lock_as_irq(&dev->gc, pin); + if (ret) { + dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n"); + goto err_desc; + } + + ret = gpiod_to_irq(dev->desc[pin]); + if (ret < 0) { + dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n"); + goto err_lock; + } + + return ret; + +err_lock: + gpiochip_unlock_as_irq(&dev->gc, pin); +err_desc: + gpiochip_free_own_desc(dev->desc[pin]); + dev->desc[pin] = NULL; + return ret; +} + static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) { struct cp2112_device *dev; @@ -1163,8 +1341,17 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) chmod_sysfs_attrs(hdev); hid_hw_power(hdev, PM_HINT_NORMAL); + ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0, + handle_simple_irq, IRQ_TYPE_NONE); + if (ret) { + dev_err(dev->gc.parent, "failed to add IRQ chip\n"); + goto err_sysfs_remove; + } + return ret; +err_sysfs_remove: + sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); err_gpiochip_remove: gpiochip_remove(&dev->gc); err_free_i2c: @@ -1181,10 +1368,22 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) static void cp2112_remove(struct hid_device *hdev) { struct cp2112_device *dev = hid_get_drvdata(hdev); + int i; sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); - gpiochip_remove(&dev->gc); i2c_del_adapter(&dev->adap); + + if (dev->gpio_poll) { + dev->gpio_poll = false; + cancel_delayed_work_sync(&dev->gpio_poll_worker); + } + + for (i = 0; i < ARRAY_SIZE(dev->desc); i++) { + gpiochip_unlock_as_irq(&dev->gc, i); + gpiochip_free_own_desc(dev->desc[i]); + } + + gpiochip_remove(&dev->gc); /* i2c_del_adapter has finished removing all i2c devices from our * adapter. Well behaved devices should no longer call our cp2112_xfer * and should have waited for any pending calls to finish. It has also -- 2.7.4