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Release 4.14 drivers/gpio/gpio-htc-egpio.c

Directory: drivers/gpio
/*
 * Support for the GPIO/IRQ expander chips present on several HTC phones.
 * These are implemented in CPLD chips present on the board.
 *
 * Copyright (c) 2007 Kevin O'Connor <kevin@koconnor.net>
 * Copyright (c) 2007 Philipp Zabel <philipp.zabel@gmail.com>
 *
 * This file may be distributed under the terms of the GNU GPL license.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/platform_data/gpio-htc-egpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/init.h>


struct egpio_chip {
	
int              reg_start;
	
int              cached_values;
	
unsigned long    is_out;
	
struct device    *dev;
	
struct gpio_chip chip;
};


struct egpio_info {
	
spinlock_t        lock;

	/* iomem info */
	
void __iomem      *base_addr;
	
int               bus_shift;	/* byte shift */
	
int               reg_shift;	/* bit shift */
	
int               reg_mask;

	/* irq info */
	
int               ack_register;
	
int               ack_write;
	
u16               irqs_enabled;
	
uint              irq_start;
	
int               nirqs;
	
uint              chained_irq;

	/* egpio info */
	
struct egpio_chip *chip;
	
int               nchips;
};


static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg) { writew(value, ei->base_addr + (reg << ei->bus_shift)); }

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static inline u16 egpio_readw(struct egpio_info *ei, int reg) { return readw(ei->base_addr + (reg << ei->bus_shift)); }

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/* * IRQs */
static inline void ack_irqs(struct egpio_info *ei) { egpio_writew(ei->ack_write, ei, ei->ack_register); pr_debug("EGPIO ack - write %x to base+%x\n", ei->ack_write, ei->ack_register << ei->bus_shift); }

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static void egpio_ack(struct irq_data *data) { }

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/* There does not appear to be a way to proactively mask interrupts * on the egpio chip itself. So, we simply ignore interrupts that * aren't desired. */
static void egpio_mask(struct irq_data *data) { struct egpio_info *ei = irq_data_get_irq_chip_data(data); ei->irqs_enabled &= ~(1 << (data->irq - ei->irq_start)); pr_debug("EGPIO mask %d %04x\n", data->irq, ei->irqs_enabled); }

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static void egpio_unmask(struct irq_data *data) { struct egpio_info *ei = irq_data_get_irq_chip_data(data); ei->irqs_enabled |= 1 << (data->irq - ei->irq_start); pr_debug("EGPIO unmask %d %04x\n", data->irq, ei->irqs_enabled); }

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static struct irq_chip egpio_muxed_chip = { .name = "htc-egpio", .irq_ack = egpio_ack, .irq_mask = egpio_mask, .irq_unmask = egpio_unmask, };
static void egpio_handler(struct irq_desc *desc) { struct egpio_info *ei = irq_desc_get_handler_data(desc); int irqpin; /* Read current pins. */ unsigned long readval = egpio_readw(ei, ei->ack_register); pr_debug("IRQ reg: %x\n", (unsigned int)readval); /* Ack/unmask interrupts. */ ack_irqs(ei); /* Process all set pins. */ readval &= ei->irqs_enabled; for_each_set_bit(irqpin, &readval, ei->nirqs) { /* Run irq handler */ pr_debug("got IRQ %d\n", irqpin); generic_handle_irq(ei->irq_start + irqpin); } }

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int htc_egpio_get_wakeup_irq(struct device *dev) { struct egpio_info *ei = dev_get_drvdata(dev); /* Read current pins. */ u16 readval = egpio_readw(ei, ei->ack_register); /* Ack/unmask interrupts. */ ack_irqs(ei); /* Return first set pin. */ readval &= ei->irqs_enabled; return ei->irq_start + ffs(readval) - 1; }

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EXPORT_SYMBOL(htc_egpio_get_wakeup_irq);
static inline int egpio_pos(struct egpio_info *ei, int bit) { return bit >> ei->reg_shift; }

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static inline int egpio_bit(struct egpio_info *ei, int bit) { return 1 << (bit & ((1 << ei->reg_shift)-1)); }

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/* * Input pins */
static int egpio_get(struct gpio_chip *chip, unsigned offset) { struct egpio_chip *egpio; struct egpio_info *ei; unsigned bit; int reg; int value; pr_debug("egpio_get_value(%d)\n", chip->base + offset); egpio = gpiochip_get_data(chip); ei = dev_get_drvdata(egpio->dev); bit = egpio_bit(ei, offset); reg = egpio->reg_start + egpio_pos(ei, offset); if (test_bit(offset, &egpio->is_out)) { return !!(egpio->cached_values & (1 << offset)); } else { value = egpio_readw(ei, reg); pr_debug("readw(%p + %x) = %x\n", ei->base_addr, reg << ei->bus_shift, value); return !!(value & bit); } }

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static int egpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct egpio_chip *egpio; egpio = gpiochip_get_data(chip); return test_bit(offset, &egpio->is_out) ? -EINVAL : 0; }

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/* * Output pins */
static void egpio_set(struct gpio_chip *chip, unsigned offset, int value) { unsigned long flag; struct egpio_chip *egpio; struct egpio_info *ei; unsigned bit; int pos; int reg; int shift; pr_debug("egpio_set(%s, %d(%d), %d)\n", chip->label, offset, offset+chip->base, value); egpio = gpiochip_get_data(chip); ei = dev_get_drvdata(egpio->dev); bit = egpio_bit(ei, offset); pos = egpio_pos(ei, offset); reg = egpio->reg_start + pos; shift = pos << ei->reg_shift; pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear", reg, (egpio->cached_values >> shift) & ei->reg_mask); spin_lock_irqsave(&ei->lock, flag); if (value) egpio->cached_values |= (1 << offset); else egpio->cached_values &= ~(1 << offset); egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg); spin_unlock_irqrestore(&ei->lock, flag); }

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static int egpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { struct egpio_chip *egpio; egpio = gpiochip_get_data(chip); if (test_bit(offset, &egpio->is_out)) { egpio_set(chip, offset, value); return 0; } else { return -EINVAL; } }

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static int egpio_get_direction(struct gpio_chip *chip, unsigned offset) { struct egpio_chip *egpio; egpio = gpiochip_get_data(chip); return !test_bit(offset, &egpio->is_out); }

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static void egpio_write_cache(struct egpio_info *ei) { int i; struct egpio_chip *egpio; int shift; for (i = 0; i < ei->nchips; i++) { egpio = &(ei->chip[i]); if (!egpio->is_out) continue; for (shift = 0; shift < egpio->chip.ngpio; shift += (1<<ei->reg_shift)) { int reg = egpio->reg_start + egpio_pos(ei, shift); if (!((egpio->is_out >> shift) & ei->reg_mask)) continue; pr_debug("EGPIO: setting %x to %x, was %x\n", reg, (egpio->cached_values >> shift) & ei->reg_mask, egpio_readw(ei, reg)); egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg); } } }

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/* * Setup */
static int __init egpio_probe(struct platform_device *pdev) { struct htc_egpio_platform_data *pdata = dev_get_platdata(&pdev->dev); struct resource *res; struct egpio_info *ei; struct gpio_chip *chip; unsigned int irq, irq_end; int i; int ret; /* Initialize ei data structure. */ ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL); if (!ei) return -ENOMEM; spin_lock_init(&ei->lock); /* Find chained irq */ ret = -EINVAL; res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (res) ei->chained_irq = res->start; /* Map egpio chip into virtual address space. */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) goto fail; ei->base_addr = devm_ioremap_nocache(&pdev->dev, res->start, resource_size(res)); if (!ei->base_addr) goto fail; pr_debug("EGPIO phys=%08x virt=%p\n", (u32)res->start, ei->base_addr); if ((pdata->bus_width != 16) && (pdata->bus_width != 32)) goto fail; ei->bus_shift = fls(pdata->bus_width - 1) - 3; pr_debug("bus_shift = %d\n", ei->bus_shift); if ((pdata->reg_width != 8) && (pdata->reg_width != 16)) goto fail; ei->reg_shift = fls(pdata->reg_width - 1); pr_debug("reg_shift = %d\n", ei->reg_shift); ei->reg_mask = (1 << pdata->reg_width) - 1; platform_set_drvdata(pdev, ei); ei->nchips = pdata->num_chips; ei->chip = devm_kzalloc(&pdev->dev, sizeof(struct egpio_chip) * ei->nchips, GFP_KERNEL); if (!ei->chip) { ret = -ENOMEM; goto fail; } for (i = 0; i < ei->nchips; i++) { ei->chip[i].reg_start = pdata->chip[i].reg_start; ei->chip[i].cached_values = pdata->chip[i].initial_values; ei->chip[i].is_out = pdata->chip[i].direction; ei->chip[i].dev = &(pdev->dev); chip = &(ei->chip[i].chip); chip->label = "htc-egpio"; chip->parent = &pdev->dev; chip->owner = THIS_MODULE; chip->get = egpio_get; chip->set = egpio_set; chip->direction_input = egpio_direction_input; chip->direction_output = egpio_direction_output; chip->get_direction = egpio_get_direction; chip->base = pdata->chip[i].gpio_base; chip->ngpio = pdata->chip[i].num_gpios; gpiochip_add_data(chip, &ei->chip[i]); } /* Set initial pin values */ egpio_write_cache(ei); ei->irq_start = pdata->irq_base; ei->nirqs = pdata->num_irqs; ei->ack_register = pdata->ack_register; if (ei->chained_irq) { /* Setup irq handlers */ ei->ack_write = 0xFFFF; if (pdata->invert_acks) ei->ack_write = 0; irq_end = ei->irq_start + ei->nirqs; for (irq = ei->irq_start; irq < irq_end; irq++) { irq_set_chip_and_handler(irq, &egpio_muxed_chip, handle_simple_irq); irq_set_chip_data(irq, ei); irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); } irq_set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING); irq_set_chained_handler_and_data(ei->chained_irq, egpio_handler, ei); ack_irqs(ei); device_init_wakeup(&pdev->dev, 1); } return 0; fail: printk(KERN_ERR "EGPIO failed to setup\n"); return ret; }

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Thomas Gleixner81.16%320.00%
Wei Yongjun60.87%16.67%
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Julia Lawall20.29%16.67%
Total692100.00%15100.00%

#ifdef CONFIG_PM
static int egpio_suspend(struct platform_device *pdev, pm_message_t state) { struct egpio_info *ei = platform_get_drvdata(pdev); if (ei->chained_irq && device_may_wakeup(&pdev->dev)) enable_irq_wake(ei->chained_irq); return 0; }

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static int egpio_resume(struct platform_device *pdev) { struct egpio_info *ei = platform_get_drvdata(pdev); if (ei->chained_irq && device_may_wakeup(&pdev->dev)) disable_irq_wake(ei->chained_irq); /* Update registers from the cache, in case the CPLD was powered off during suspend */ egpio_write_cache(ei); return 0; }

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#else #define egpio_suspend NULL #define egpio_resume NULL #endif static struct platform_driver egpio_driver = { .driver = { .name = "htc-egpio", .suppress_bind_attrs = true, }, .suspend = egpio_suspend, .resume = egpio_resume, };
static int __init egpio_init(void) { return platform_driver_probe(&egpio_driver, egpio_probe); }

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/* start early for dependencies */ subsys_initcall(egpio_init);

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Lee Jones120.58%14.35%
Thomas Gleixner120.58%417.39%
Wei Yongjun60.29%14.35%
Paul Gortmaker40.19%14.35%
Jingoo Han40.19%14.35%
Samuel Ortiz30.14%14.35%
Rob Herring30.14%14.35%
Julia Lawall20.10%14.35%
Tejun Heo20.10%14.35%
Akinobu Mita10.05%14.35%
Total2086100.00%23100.00%
Directory: drivers/gpio
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