Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753952Ab0DWV2u (ORCPT ); Fri, 23 Apr 2010 17:28:50 -0400 Received: from tex.lwn.net ([70.33.254.29]:50546 "EHLO vena.lwn.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753163Ab0DWV2g (ORCPT ); Fri, 23 Apr 2010 17:28:36 -0400 From: Jonathan Corbet To: linux-kernel@vger.kernel.org Cc: Harald Welte , Deepak Saxena , linux-fbdev@vger.kernel.org, JosephChan@via.com.tw, ScottFang@viatech.com.cn, Florian Tobias Schandinat Subject: [PATCH 03/13] viafb: add a driver for GPIO lines Date: Fri, 23 Apr 2010 15:28:03 -0600 Message-Id: <1272058093-20914-4-git-send-email-corbet@lwn.net> X-Mailer: git-send-email 1.7.0.1 In-Reply-To: <1272058093-20914-1-git-send-email-corbet@lwn.net> References: <1272058093-20914-1-git-send-email-corbet@lwn.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9665 Lines: 361 This is a simple gpiolib driver giving access to the GPIO lines in the VIA framebuffer system. A simple mechanism exists for switching lines between GPIO and I2C, but it's only compile-time for now. Signed-off-by: Jonathan Corbet --- drivers/video/via/Makefile | 4 +- drivers/video/via/via-core.c | 7 + drivers/video/via/via-gpio.c | 268 ++++++++++++++++++++++++++++++++++++++++++ drivers/video/via/via-gpio.h | 15 +++ 4 files changed, 293 insertions(+), 1 deletions(-) create mode 100644 drivers/video/via/via-gpio.c create mode 100644 drivers/video/via/via-gpio.h diff --git a/drivers/video/via/Makefile b/drivers/video/via/Makefile index e6d2a2b..a4db686 100644 --- a/drivers/video/via/Makefile +++ b/drivers/video/via/Makefile @@ -4,4 +4,6 @@ obj-$(CONFIG_FB_VIA) += viafb.o via-core.o -viafb-y :=viafbdev.o hw.o via_i2c.o dvi.o lcd.o ioctl.o accel.o via_utility.o vt1636.o global.o tblDPASetting.o viamode.o tbl1636.o +viafb-y :=viafbdev.o hw.o via_i2c.o dvi.o lcd.o ioctl.o accel.o \ + via_utility.o vt1636.o global.o tblDPASetting.o viamode.o tbl1636.o \ + via-gpio.o diff --git a/drivers/video/via/via-core.c b/drivers/video/via/via-core.c index 1e6789d..00b9021 100644 --- a/drivers/video/via/via-core.c +++ b/drivers/video/via/via-core.c @@ -9,6 +9,7 @@ */ #include "via-core.h" #include "via_i2c.h" +#include "via-gpio.h" #include "global.h" #include @@ -223,6 +224,11 @@ static int __devinit via_pci_probe(struct pci_dev *pdev, via_fb_pci_remove(pdev); return ret; } + /* + * Create the GPIOs. We continue whether or not this succeeds; + * the framebuffer might be useful even without GPIO ports. + */ + ret = viafb_create_gpios(&global_dev, adap_configs); return 0; out_teardown: @@ -232,6 +238,7 @@ out_teardown: static void __devexit via_pci_remove(struct pci_dev *pdev) { + viafb_destroy_gpios(); viafb_delete_i2c_busses(); via_fb_pci_remove(pdev); via_pci_teardown_mmio(&global_dev); diff --git a/drivers/video/via/via-gpio.c b/drivers/video/via/via-gpio.c new file mode 100644 index 0000000..e119d21 --- /dev/null +++ b/drivers/video/via/via-gpio.c @@ -0,0 +1,268 @@ +/* + * Support for viafb GPIO ports. + * + * Copyright 2009 Jonathan Corbet + * Distributable under version 2 of the GNU General Public License. + */ + +#include +#include +#include "via-core.h" +#include "via-gpio.h" +#include "global.h" + +/* + * The ports we know about. Note that the port-25 gpios are not + * mentioned in the datasheet. + */ + +struct viafb_gpio { + char *vg_name; /* Data sheet name */ + u16 vg_io_port; + u8 vg_port_index; + int vg_mask_shift; +}; + +static struct viafb_gpio viafb_all_gpios[] = { + { + .vg_name = "VGPIO0", /* Guess - not in datasheet */ + .vg_io_port = VIASR, + .vg_port_index = 0x25, + .vg_mask_shift = 1 + }, + { + .vg_name = "VGPIO1", + .vg_io_port = VIASR, + .vg_port_index = 0x25, + .vg_mask_shift = 0 + }, + { + .vg_name = "VGPIO2", /* aka DISPCLKI0 */ + .vg_io_port = VIASR, + .vg_port_index = 0x2c, + .vg_mask_shift = 1 + }, + { + .vg_name = "VGPIO3", /* aka DISPCLKO0 */ + .vg_io_port = VIASR, + .vg_port_index = 0x2c, + .vg_mask_shift = 0 + }, + { + .vg_name = "VGPIO4", /* DISPCLKI1 */ + .vg_io_port = VIASR, + .vg_port_index = 0x3d, + .vg_mask_shift = 1 + }, + { + .vg_name = "VGPIO5", /* DISPCLKO1 */ + .vg_io_port = VIASR, + .vg_port_index = 0x3d, + .vg_mask_shift = 0 + }, +}; + +#define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios) + +/* + * This structure controls the active GPIOs, which may be a subset + * of those which are known. + */ + +struct viafb_gpio_cfg { + struct gpio_chip gpio_chip; + struct viafb_dev *vdev; + struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS]; + char *gpio_names[VIAFB_NUM_GPIOS]; +}; + +/* + * GPIO access functions + */ +static void via_gpio_set(struct gpio_chip *chip, unsigned int nr, + int value) +{ + struct viafb_gpio_cfg *cfg = container_of(chip, + struct viafb_gpio_cfg, + gpio_chip); + u8 reg; + struct viafb_gpio *gpio; + unsigned long flags; + + spin_lock_irqsave(&cfg->vdev->reg_lock, flags); + gpio = cfg->active_gpios[nr]; + reg = viafb_read_reg(VIASR, gpio->vg_port_index); + reg |= 0x40 << gpio->vg_mask_shift; /* output enable */ + if (value) + reg |= 0x10 << gpio->vg_mask_shift; + else + reg &= ~(0x10 << gpio->vg_mask_shift); + viafb_write_reg(gpio->vg_port_index, VIASR, reg); + spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); +} + +static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr, + int value) +{ + via_gpio_set(chip, nr, value); + return 0; +} + +/* + * Set the input direction. I'm not sure this is right; we should + * be able to do input without disabling output. + */ +static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr) +{ + struct viafb_gpio_cfg *cfg = container_of(chip, + struct viafb_gpio_cfg, + gpio_chip); + struct viafb_gpio *gpio; + unsigned long flags; + + spin_lock_irqsave(&cfg->vdev->reg_lock, flags); + gpio = cfg->active_gpios[nr]; + viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0, + 0x40 << gpio->vg_mask_shift); + spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); + return 0; +} + +static int via_gpio_get(struct gpio_chip *chip, unsigned int nr) +{ + struct viafb_gpio_cfg *cfg = container_of(chip, + struct viafb_gpio_cfg, + gpio_chip); + u8 reg; + struct viafb_gpio *gpio; + unsigned long flags; + + spin_lock_irqsave(&cfg->vdev->reg_lock, flags); + gpio = cfg->active_gpios[nr]; + reg = viafb_read_reg(VIASR, gpio->vg_port_index); + spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); + return reg & (0x04 << gpio->vg_mask_shift); +} + + +static struct viafb_gpio_cfg gpio_config = { + .gpio_chip = { + .label = "VIAFB onboard GPIO", + .owner = THIS_MODULE, + .direction_output = via_gpio_dir_out, + .set = via_gpio_set, + .direction_input = via_gpio_dir_input, + .get = via_gpio_get, + .base = -1, + .ngpio = 0, + .can_sleep = 0 + } +}; + +/* + * Manage the software enable bit. + */ +static void viafb_gpio_enable(struct viafb_gpio *gpio) +{ + viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0x02, 0x02); +} + +static void viafb_gpio_disable(struct viafb_gpio *gpio) +{ + viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0, 0x02); +} + + + + +int viafb_create_gpios(struct viafb_dev *vdev, + const struct via_port_cfg *port_cfg) +{ + int i, ngpio = 0, ret; + struct viafb_gpio *gpio; + unsigned long flags; + + /* + * Set up entries for all GPIOs which have been configured to + * operate as such (as opposed to as i2c ports). + */ + for (i = 0; i < VIAFB_NUM_PORTS; i++) { + if (port_cfg[i].mode != VIA_MODE_GPIO) + continue; + for (gpio = viafb_all_gpios; + gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++) + if (gpio->vg_port_index == port_cfg[i].ioport_index) { + gpio_config.active_gpios[ngpio] = gpio; + gpio_config.gpio_names[ngpio] = gpio->vg_name; + ngpio++; + } + } + gpio_config.gpio_chip.ngpio = ngpio; + gpio_config.gpio_chip.names = gpio_config.gpio_names; + gpio_config.vdev = vdev; + if (ngpio == 0) { + printk(KERN_INFO "viafb: no GPIOs configured\n"); + return 0; + } + /* + * Enable the ports. They come in pairs, with a single + * enable bit for both. + */ + spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags); + for (i = 0; i < ngpio; i += 2) + viafb_gpio_enable(gpio_config.active_gpios[i]); + spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags); + /* + * Get registered. + */ + gpio_config.gpio_chip.base = -1; /* Dynamic */ + ret = gpiochip_add(&gpio_config.gpio_chip); + if (ret) { + printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret); + gpio_config.gpio_chip.ngpio = 0; + } + return ret; +/* Port enable ? */ +} + + +int viafb_destroy_gpios(void) +{ + unsigned long flags; + int ret = 0, i; + + spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags); + /* + * Get unregistered. + */ + if (gpio_config.gpio_chip.ngpio > 0) { + ret = gpiochip_remove(&gpio_config.gpio_chip); + if (ret) { /* Somebody still using it? */ + printk(KERN_ERR "Viafb: GPIO remove failed\n"); + goto out; + } + } + /* + * Disable the ports. + */ + for (i = 0; i < gpio_config.gpio_chip.ngpio; i += 2) + viafb_gpio_disable(gpio_config.active_gpios[i]); + gpio_config.gpio_chip.ngpio = 0; +out: + spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags); + return ret; +} + +/* + * Look up a specific gpio and return the number it was assigned. + */ +int viafb_gpio_lookup(const char *name) +{ + int i; + + for (i = 0; i < gpio_config.gpio_chip.ngpio; i++) + if (!strcmp(name, gpio_config.active_gpios[i]->vg_name)) + return gpio_config.gpio_chip.base + i; + return -1; +} +EXPORT_SYMBOL_GPL(viafb_gpio_lookup); diff --git a/drivers/video/via/via-gpio.h b/drivers/video/via/via-gpio.h new file mode 100644 index 0000000..7b53f96 --- /dev/null +++ b/drivers/video/via/via-gpio.h @@ -0,0 +1,15 @@ +/* + * Support for viafb GPIO ports. + * + * Copyright 2009 Jonathan Corbet + * Distributable under version 2 of the GNU General Public License. + */ + +#ifndef __VIA_GPIO_H__ +#define __VIA_GPIO_H__ + +extern int viafb_create_gpios(struct viafb_dev *vdev, + const struct via_port_cfg *port_cfg); +extern int viafb_destroy_gpios(void); +extern int viafb_gpio_lookup(const char *name); +#endif -- 1.7.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/