| /* |
| * GE PIO2 GPIO Driver |
| * |
| * Author: Martyn Welch <martyn.welch@ge.com> |
| * Copyright 2009 GE Intelligent Platforms Embedded Systems, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/device.h> |
| #include <linux/platform_device.h> |
| #include <linux/ctype.h> |
| #include <linux/gpio.h> |
| #include <linux/slab.h> |
| #include <linux/vme.h> |
| |
| #include "vme_pio2.h" |
| |
| static const char driver_name[] = "pio2_gpio"; |
| |
| static struct pio2_card *gpio_to_pio2_card(struct gpio_chip *chip) |
| { |
| return container_of(chip, struct pio2_card, gc); |
| } |
| |
| static int pio2_gpio_get(struct gpio_chip *chip, unsigned int offset) |
| { |
| u8 reg; |
| int retval; |
| struct pio2_card *card = gpio_to_pio2_card(chip); |
| |
| if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) | |
| (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| |
| dev_err(&card->vdev->dev, "Channel not available as input\n"); |
| return 0; |
| } |
| |
| retval = vme_master_read(card->window, ®, 1, |
| PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]); |
| if (retval < 0) { |
| dev_err(&card->vdev->dev, "Unable to read from GPIO\n"); |
| return 0; |
| } |
| |
| /* |
| * Remember, input on channels configured as both input and output |
| * are inverted! |
| */ |
| if (reg & PIO2_CHANNEL_BIT[offset]) { |
| if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH) |
| return 0; |
| |
| return 1; |
| } |
| |
| if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH) |
| return 1; |
| |
| return 0; |
| } |
| |
| static void pio2_gpio_set(struct gpio_chip *chip, |
| unsigned int offset, int value) |
| { |
| u8 reg; |
| int retval; |
| struct pio2_card *card = gpio_to_pio2_card(chip); |
| |
| if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) | |
| (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| |
| dev_err(&card->vdev->dev, "Channel not available as output\n"); |
| return; |
| } |
| |
| if (value) |
| reg = card->bank[PIO2_CHANNEL_BANK[offset]].value | |
| PIO2_CHANNEL_BIT[offset]; |
| else |
| reg = card->bank[PIO2_CHANNEL_BANK[offset]].value & |
| ~PIO2_CHANNEL_BIT[offset]; |
| |
| retval = vme_master_write(card->window, ®, 1, |
| PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]); |
| if (retval < 0) { |
| dev_err(&card->vdev->dev, "Unable to write to GPIO\n"); |
| return; |
| } |
| |
| card->bank[PIO2_CHANNEL_BANK[offset]].value = reg; |
| } |
| |
| /* Directionality configured at board build - send appropriate response */ |
| static int pio2_gpio_dir_in(struct gpio_chip *chip, unsigned offset) |
| { |
| int data; |
| struct pio2_card *card = gpio_to_pio2_card(chip); |
| |
| if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) | |
| (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| dev_err(&card->vdev->dev, |
| "Channel directionality not configurable at runtime\n"); |
| |
| data = -EINVAL; |
| } else { |
| data = 0; |
| } |
| |
| return data; |
| } |
| |
| /* Directionality configured at board build - send appropriate response */ |
| static int pio2_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value) |
| { |
| int data; |
| struct pio2_card *card = gpio_to_pio2_card(chip); |
| |
| if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) | |
| (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| dev_err(&card->vdev->dev, |
| "Channel directionality not configurable at runtime\n"); |
| |
| data = -EINVAL; |
| } else { |
| data = 0; |
| } |
| |
| return data; |
| } |
| |
| /* |
| * We return whether this has been successful - this is used in the probe to |
| * ensure we have a valid card. |
| */ |
| int pio2_gpio_reset(struct pio2_card *card) |
| { |
| int retval = 0; |
| int i, j; |
| |
| u8 data = 0; |
| |
| /* Zero output registers */ |
| for (i = 0; i < 4; i++) { |
| retval = vme_master_write(card->window, &data, 1, |
| PIO2_REGS_DATA[i]); |
| if (retval < 0) |
| return retval; |
| card->bank[i].value = 0; |
| } |
| |
| /* Set input interrupt masks */ |
| for (i = 0; i < 4; i++) { |
| retval = vme_master_write(card->window, &data, 1, |
| PIO2_REGS_INT_MASK[i * 2]); |
| if (retval < 0) |
| return retval; |
| |
| retval = vme_master_write(card->window, &data, 1, |
| PIO2_REGS_INT_MASK[(i * 2) + 1]); |
| if (retval < 0) |
| return retval; |
| |
| for (j = 0; j < 8; j++) |
| card->bank[i].irq[j] = NONE; |
| } |
| |
| /* Ensure all I/O interrupts are cleared */ |
| for (i = 0; i < 4; i++) { |
| do { |
| retval = vme_master_read(card->window, &data, 1, |
| PIO2_REGS_INT_STAT[i]); |
| if (retval < 0) |
| return retval; |
| } while (data != 0); |
| } |
| |
| return 0; |
| } |
| |
| int pio2_gpio_init(struct pio2_card *card) |
| { |
| int retval = 0; |
| char *label; |
| |
| label = kasprintf(GFP_KERNEL, |
| "%s@%s", driver_name, dev_name(&card->vdev->dev)); |
| if (label == NULL) |
| return -ENOMEM; |
| |
| card->gc.label = label; |
| |
| card->gc.ngpio = PIO2_NUM_CHANNELS; |
| /* Dynamic allocation of base */ |
| card->gc.base = -1; |
| /* Setup pointers to chip functions */ |
| card->gc.direction_input = pio2_gpio_dir_in; |
| card->gc.direction_output = pio2_gpio_dir_out; |
| card->gc.get = pio2_gpio_get; |
| card->gc.set = pio2_gpio_set; |
| |
| /* This function adds a memory mapped GPIO chip */ |
| retval = gpiochip_add(&(card->gc)); |
| if (retval) { |
| dev_err(&card->vdev->dev, "Unable to register GPIO\n"); |
| kfree(card->gc.label); |
| } |
| |
| return retval; |
| }; |
| |
| void pio2_gpio_exit(struct pio2_card *card) |
| { |
| const char *label = card->gc.label; |
| |
| gpiochip_remove(&(card->gc)); |
| kfree(label); |
| } |
| |