/* * linux/drivers/mfd/ucb1x00-core.c * * Copyright (C) 2001 Russell King, All Rights Reserved. * * 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. * * The UCB1x00 core driver provides basic services for handling IO, * the ADC, interrupts, and accessing registers. It is designed * such that everything goes through this layer, thereby providing * a consistent locking methodology, as well as allowing the drivers * to be used on other non-MCP-enabled hardware platforms. * * Note that all locks are private to this file. Nothing else may * touch them. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/device.h> #include <linux/mutex.h> #include <asm/dma.h> #include <asm/hardware.h> #include "ucb1x00.h" static DEFINE_MUTEX(ucb1x00_mutex); static LIST_HEAD(ucb1x00_drivers); static LIST_HEAD(ucb1x00_devices); /** * ucb1x00_io_set_dir - set IO direction * @ucb: UCB1x00 structure describing chip * @in: bitfield of IO pins to be set as inputs * @out: bitfield of IO pins to be set as outputs * * Set the IO direction of the ten general purpose IO pins on * the UCB1x00 chip. The @in bitfield has priority over the * @out bitfield, in that if you specify a pin as both input * and output, it will end up as an input. * * ucb1x00_enable must have been called to enable the comms * before using this function. * * This function takes a spinlock, disabling interrupts. */ void ucb1x00_io_set_dir(struct ucb1x00 *ucb, unsigned int in, unsigned int out) { unsigned long flags; spin_lock_irqsave(&ucb->io_lock, flags); ucb->io_dir |= out; ucb->io_dir &= ~in; ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir); spin_unlock_irqrestore(&ucb->io_lock, flags); } /** * ucb1x00_io_write - set or clear IO outputs * @ucb: UCB1x00 structure describing chip * @set: bitfield of IO pins to set to logic '1' * @clear: bitfield of IO pins to set to logic '0' * * Set the IO output state of the specified IO pins. The value * is retained if the pins are subsequently configured as inputs. * The @clear bitfield has priority over the @set bitfield - * outputs will be cleared. * * ucb1x00_enable must have been called to enable the comms * before using this function. * * This function takes a spinlock, disabling interrupts. */ void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear) { unsigned long flags; spin_lock_irqsave(&ucb->io_lock, flags); ucb->io_out |= set; ucb->io_out &= ~clear; ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out); spin_unlock_irqrestore(&ucb->io_lock, flags); } /** * ucb1x00_io_read - read the current state of the IO pins * @ucb: UCB1x00 structure describing chip * * Return a bitfield describing the logic state of the ten * general purpose IO pins. * * ucb1x00_enable must have been called to enable the comms * before using this function. * * This function does not take any semaphores or spinlocks. */ unsigned int ucb1x00_io_read(struct ucb1x00 *ucb) { return ucb1x00_reg_read(ucb, UCB_IO_DATA); } /* * UCB1300 data sheet says we must: * 1. enable ADC => 5us (including reference startup time) * 2. select input => 51*tsibclk => 4.3us * 3. start conversion => 102*tsibclk => 8.5us * (tsibclk = 1/11981000) * Period between SIB 128-bit frames = 10.7us */ /** * ucb1x00_adc_enable - enable the ADC converter * @ucb: UCB1x00 structure describing chip * * Enable the ucb1x00 and ADC converter on the UCB1x00 for use. * Any code wishing to use the ADC converter must call this * function prior to using it. * * This function takes the ADC semaphore to prevent two or more * concurrent uses, and therefore may sleep. As a result, it * can only be called from process context, not interrupt * context. * * You should release the ADC as soon as possible using * ucb1x00_adc_disable. */ void ucb1x00_adc_enable(struct ucb1x00 *ucb) { down(&ucb->adc_sem); ucb->adc_cr |= UCB_ADC_ENA; ucb1x00_enable(ucb); ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr); } /** * ucb1x00_adc_read - read the specified ADC channel * @ucb: UCB1x00 structure describing chip * @adc_channel: ADC channel mask * @sync: wait for syncronisation pulse. * * Start an ADC conversion and wait for the result. Note that * synchronised ADC conversions (via the ADCSYNC pin) must wait * until the trigger is asserted and the conversion is finished. * * This function currently spins waiting for the conversion to * complete (2 frames max without sync). * * If called for a synchronised ADC conversion, it may sleep * with the ADC semaphore held. */ unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync) { unsigned int val; if (sync) adc_channel |= UCB_ADC_SYNC_ENA; ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel); ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel | UCB_ADC_START); for (;;) { val = ucb1x00_reg_read(ucb, UCB_ADC_DATA); if (val & UCB_ADC_DAT_VAL) break; /* yield to other processes */ set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(1); } return UCB_ADC_DAT(val); } /** * ucb1x00_adc_disable - disable the ADC converter * @ucb: UCB1x00 structure describing chip * * Disable the ADC converter and release the ADC semaphore. */ void ucb1x00_adc_disable(struct ucb1x00 *ucb) { ucb->adc_cr &= ~UCB_ADC_ENA; ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr); ucb1x00_disable(ucb); up(&ucb->adc_sem); } /* * UCB1x00 Interrupt handling. * * The UCB1x00 can generate interrupts when the SIBCLK is stopped. * Since we need to read an internal register, we must re-enable * SIBCLK to talk to the chip. We leave the clock running until * we have finished processing all interrupts from the chip. */ static irqreturn_t ucb1x00_irq(int irqnr, void *devid) { struct ucb1x00 *ucb = devid; struct ucb1x00_irq *irq; unsigned int isr, i; ucb1x00_enable(ucb); isr = ucb1x00_reg_read(ucb, UCB_IE_STATUS); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0); for (i = 0, irq = ucb->irq_handler; i < 16 && isr; i++, isr >>= 1, irq++) if (isr & 1 && irq->fn) irq->fn(i, irq->devid); ucb1x00_disable(ucb); return IRQ_HANDLED; } /** * ucb1x00_hook_irq - hook a UCB1x00 interrupt * @ucb: UCB1x00 structure describing chip * @idx: interrupt index * @fn: function to call when interrupt is triggered * @devid: device id to pass to interrupt handler * * Hook the specified interrupt. You can only register one handler * for each interrupt source. The interrupt source is not enabled * by this function; use ucb1x00_enable_irq instead. * * Interrupt handlers will be called with other interrupts enabled. * * Returns zero on success, or one of the following errors: * -EINVAL if the interrupt index is invalid * -EBUSY if the interrupt has already been hooked */ int ucb1x00_hook_irq(struct ucb1x00 *ucb, unsigned int idx, void (*fn)(int, void *), void *devid) { struct ucb1x00_irq *irq; int ret = -EINVAL; if (idx < 16) { irq = ucb->irq_handler + idx; ret = -EBUSY; spin_lock_irq(&ucb->lock); if (irq->fn == NULL) { irq->devid = devid; irq->fn = fn; ret = 0; } spin_unlock_irq(&ucb->lock); } return ret; } /** * ucb1x00_enable_irq - enable an UCB1x00 interrupt source * @ucb: UCB1x00 structure describing chip * @idx: interrupt index * @edges: interrupt edges to enable * * Enable the specified interrupt to trigger on %UCB_RISING, * %UCB_FALLING or both edges. The interrupt should have been * hooked by ucb1x00_hook_irq. */ void ucb1x00_enable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges) { unsigned long flags; if (idx < 16) { spin_lock_irqsave(&ucb->lock, flags); ucb1x00_enable(ucb); if (edges & UCB_RISING) { ucb->irq_ris_enbl |= 1 << idx; ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl); } if (edges & UCB_FALLING) { ucb->irq_fal_enbl |= 1 << idx; ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl); } ucb1x00_disable(ucb); spin_unlock_irqrestore(&ucb->lock, flags); } } /** * ucb1x00_disable_irq - disable an UCB1x00 interrupt source * @ucb: UCB1x00 structure describing chip * @edges: interrupt edges to disable * * Disable the specified interrupt triggering on the specified * (%UCB_RISING, %UCB_FALLING or both) edges. */ void ucb1x00_disable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges) { unsigned long flags; if (idx < 16) { spin_lock_irqsave(&ucb->lock, flags); ucb1x00_enable(ucb); if (edges & UCB_RISING) { ucb->irq_ris_enbl &= ~(1 << idx); ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl); } if (edges & UCB_FALLING) { ucb->irq_fal_enbl &= ~(1 << idx); ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl); } ucb1x00_disable(ucb); spin_unlock_irqrestore(&ucb->lock, flags); } } /** * ucb1x00_free_irq - disable and free the specified UCB1x00 interrupt * @ucb: UCB1x00 structure describing chip * @idx: interrupt index * @devid: device id. * * Disable the interrupt source and remove the handler. devid must * match the devid passed when hooking the interrupt. * * Returns zero on success, or one of the following errors: * -EINVAL if the interrupt index is invalid * -ENOENT if devid does not match */ int ucb1x00_free_irq(struct ucb1x00 *ucb, unsigned int idx, void *devid) { struct ucb1x00_irq *irq; int ret; if (idx >= 16) goto bad; irq = ucb->irq_handler + idx; ret = -ENOENT; spin_lock_irq(&ucb->lock); if (irq->devid == devid) { ucb->irq_ris_enbl &= ~(1 << idx); ucb->irq_fal_enbl &= ~(1 << idx); ucb1x00_enable(ucb); ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl); ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl); ucb1x00_disable(ucb); irq->fn = NULL; irq->devid = NULL; ret = 0; } spin_unlock_irq(&ucb->lock); return ret; bad: printk(KERN_ERR "Freeing bad UCB1x00 irq %d\n", idx); return -EINVAL; } static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv) { struct ucb1x00_dev *dev; int ret = -ENOMEM; dev = kmalloc(sizeof(struct ucb1x00_dev), GFP_KERNEL); if (dev) { dev->ucb = ucb; dev->drv = drv; ret = drv->add(dev); if (ret == 0) { list_add(&dev->dev_node, &ucb->devs); list_add(&dev->drv_node, &drv->devs); } else { kfree(dev); } } return ret; } static void ucb1x00_remove_dev(struct ucb1x00_dev *dev) { dev->drv->remove(dev); list_del(&dev->dev_node); list_del(&dev->drv_node); kfree(dev); } /* * Try to probe our interrupt, rather than relying on lots of * hard-coded machine dependencies. For reference, the expected * IRQ mappings are: * * Machine Default IRQ * adsbitsy IRQ_GPCIN4 * cerf IRQ_GPIO_UCB1200_IRQ * flexanet IRQ_GPIO_GUI * freebird IRQ_GPIO_FREEBIRD_UCB1300_IRQ * graphicsclient ADS_EXT_IRQ(8) * graphicsmaster ADS_EXT_IRQ(8) * lart LART_IRQ_UCB1200 * omnimeter IRQ_GPIO23 * pfs168 IRQ_GPIO_UCB1300_IRQ * simpad IRQ_GPIO_UCB1300_IRQ * shannon SHANNON_IRQ_GPIO_IRQ_CODEC * yopy IRQ_GPIO_UCB1200_IRQ */ static int ucb1x00_detect_irq(struct ucb1x00 *ucb) { unsigned long mask; mask = probe_irq_on(); if (!mask) { probe_irq_off(mask); return NO_IRQ; } /* * Enable the ADC interrupt. */ ucb1x00_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC); ucb1x00_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0); /* * Cause an ADC interrupt. */ ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA); ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START); /* * Wait for the conversion to complete. */ while ((ucb1x00_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VAL) == 0); ucb1x00_reg_write(ucb, UCB_ADC_CR, 0); /* * Disable and clear interrupt. */ ucb1x00_reg_write(ucb, UCB_IE_RIS, 0); ucb1x00_reg_write(ucb, UCB_IE_FAL, 0); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff); ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0); /* * Read triggered interrupt. */ return probe_irq_off(mask); } static void ucb1x00_release(struct device *dev) { struct ucb1x00 *ucb = classdev_to_ucb1x00(dev); kfree(ucb); } static struct class ucb1x00_class = { .name = "ucb1x00", .dev_release = ucb1x00_release, }; static int ucb1x00_probe(struct mcp *mcp) { struct ucb1x00 *ucb; struct ucb1x00_driver *drv; unsigned int id; int ret = -ENODEV; mcp_enable(mcp); id = mcp_reg_read(mcp, UCB_ID); if (id != UCB_ID_1200 && id != UCB_ID_1300 && id != UCB_ID_TC35143) { printk(KERN_WARNING "UCB1x00 ID not found: %04x\n", id); goto err_disable; } ucb = kzalloc(sizeof(struct ucb1x00), GFP_KERNEL); ret = -ENOMEM; if (!ucb) goto err_disable; ucb->dev.class = &ucb1x00_class; ucb->dev.parent = &mcp->attached_device; strlcpy(ucb->dev.bus_id, "ucb1x00", sizeof(ucb->dev.bus_id)); spin_lock_init(&ucb->lock); spin_lock_init(&ucb->io_lock); sema_init(&ucb->adc_sem, 1); ucb->id = id; ucb->mcp = mcp; ucb->irq = ucb1x00_detect_irq(ucb); if (ucb->irq == NO_IRQ) { printk(KERN_ERR "UCB1x00: IRQ probe failed\n"); ret = -ENODEV; goto err_free; } ret = request_irq(ucb->irq, ucb1x00_irq, IRQF_TRIGGER_RISING, "UCB1x00", ucb); if (ret) { printk(KERN_ERR "ucb1x00: unable to grab irq%d: %d\n", ucb->irq, ret); goto err_free; } mcp_set_drvdata(mcp, ucb); ret = device_register(&ucb->dev); if (ret) goto err_irq; INIT_LIST_HEAD(&ucb->devs); mutex_lock(&ucb1x00_mutex); list_add(&ucb->node, &ucb1x00_devices); list_for_each_entry(drv, &ucb1x00_drivers, node) { ucb1x00_add_dev(ucb, drv); } mutex_unlock(&ucb1x00_mutex); goto out; err_irq: free_irq(ucb->irq, ucb); err_free: kfree(ucb); err_disable: mcp_disable(mcp); out: return ret; } static void ucb1x00_remove(struct mcp *mcp) { struct ucb1x00 *ucb = mcp_get_drvdata(mcp); struct list_head *l, *n; mutex_lock(&ucb1x00_mutex); list_del(&ucb->node); list_for_each_safe(l, n, &ucb->devs) { struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, dev_node); ucb1x00_remove_dev(dev); } mutex_unlock(&ucb1x00_mutex); free_irq(ucb->irq, ucb); device_unregister(&ucb->dev); } int ucb1x00_register_driver(struct ucb1x00_driver *drv) { struct ucb1x00 *ucb; INIT_LIST_HEAD(&drv->devs); mutex_lock(&ucb1x00_mutex); list_add(&drv->node, &ucb1x00_drivers); list_for_each_entry(ucb, &ucb1x00_devices, node) { ucb1x00_add_dev(ucb, drv); } mutex_unlock(&ucb1x00_mutex); return 0; } void ucb1x00_unregister_driver(struct ucb1x00_driver *drv) { struct list_head *n, *l; mutex_lock(&ucb1x00_mutex); list_del(&drv->node); list_for_each_safe(l, n, &drv->devs) { struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, drv_node); ucb1x00_remove_dev(dev); } mutex_unlock(&ucb1x00_mutex); } static int ucb1x00_suspend(struct mcp *mcp, pm_message_t state) { struct ucb1x00 *ucb = mcp_get_drvdata(mcp); struct ucb1x00_dev *dev; mutex_lock(&ucb1x00_mutex); list_for_each_entry(dev, &ucb->devs, dev_node) { if (dev->drv->suspend) dev->drv->suspend(dev, state); } mutex_unlock(&ucb1x00_mutex); return 0; } static int ucb1x00_resume(struct mcp *mcp) { struct ucb1x00 *ucb = mcp_get_drvdata(mcp); struct ucb1x00_dev *dev; mutex_lock(&ucb1x00_mutex); list_for_each_entry(dev, &ucb->devs, dev_node) { if (dev->drv->resume) dev->drv->resume(dev); } mutex_unlock(&ucb1x00_mutex); return 0; } static struct mcp_driver ucb1x00_driver = { .drv = { .name = "ucb1x00", }, .probe = ucb1x00_probe, .remove = ucb1x00_remove, .suspend = ucb1x00_suspend, .resume = ucb1x00_resume, }; static int __init ucb1x00_init(void) { int ret = class_register(&ucb1x00_class); if (ret == 0) { ret = mcp_driver_register(&ucb1x00_driver); if (ret) class_unregister(&ucb1x00_class); } return ret; } static void __exit ucb1x00_exit(void) { mcp_driver_unregister(&ucb1x00_driver); class_unregister(&ucb1x00_class); } module_init(ucb1x00_init); module_exit(ucb1x00_exit); EXPORT_SYMBOL(ucb1x00_io_set_dir); EXPORT_SYMBOL(ucb1x00_io_write); EXPORT_SYMBOL(ucb1x00_io_read); EXPORT_SYMBOL(ucb1x00_adc_enable); EXPORT_SYMBOL(ucb1x00_adc_read); EXPORT_SYMBOL(ucb1x00_adc_disable); EXPORT_SYMBOL(ucb1x00_hook_irq); EXPORT_SYMBOL(ucb1x00_free_irq); EXPORT_SYMBOL(ucb1x00_enable_irq); EXPORT_SYMBOL(ucb1x00_disable_irq); EXPORT_SYMBOL(ucb1x00_register_driver); EXPORT_SYMBOL(ucb1x00_unregister_driver); MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); MODULE_DESCRIPTION("UCB1x00 core driver"); MODULE_LICENSE("GPL");