diff options
Diffstat (limited to 'drivers/mfd/ucb1x00-core.c')
| -rw-r--r-- | drivers/mfd/ucb1x00-core.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c new file mode 100644 index 00000000000..10f6ce1bc0a --- /dev/null +++ b/drivers/mfd/ucb1x00-core.c @@ -0,0 +1,665 @@ +/* + * 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/config.h> +#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 <asm/dma.h> +#include <asm/hardware.h> +#include <asm/irq.h> + +#include "ucb1x00.h" + +static DECLARE_MUTEX(ucb1x00_sem); +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 pt_regs *regs) +{ + 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) + 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 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) { + printk(KERN_WARNING "UCB1x00 ID not found: %04x\n", id); + goto err_disable; + } + + ucb = kmalloc(sizeof(struct ucb1x00), GFP_KERNEL); + ret = -ENOMEM; + if (!ucb) + goto err_disable; + + memset(ucb, 0, sizeof(struct ucb1x00)); + + ucb->cdev.class = &ucb1x00_class; + ucb->cdev.dev = &mcp->attached_device; + strlcpy(ucb->cdev.class_id, "ucb1x00", sizeof(ucb->cdev.class_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, 0, "UCB1x00", ucb); + if (ret) { + printk(KERN_ERR "ucb1x00: unable to grab irq%d: %d\n", + ucb->irq, ret); + goto err_free; + } + + set_irq_type(ucb->irq, IRQT_RISING); + mcp_set_drvdata(mcp, ucb); + + ret = class_device_register(&ucb->cdev); + if (ret) + goto err_irq; + + INIT_LIST_HEAD(&ucb->devs); + down(&ucb1x00_sem); + list_add(&ucb->node, &ucb1x00_devices); + list_for_each_entry(drv, &ucb1x00_drivers, node) { + ucb1x00_add_dev(ucb, drv); + } + up(&ucb1x00_sem); + 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; + + down(&ucb1x00_sem); + 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); + } + up(&ucb1x00_sem); + + free_irq(ucb->irq, ucb); + class_device_unregister(&ucb->cdev); +} + +static void ucb1x00_release(struct class_device *dev) +{ + struct ucb1x00 *ucb = classdev_to_ucb1x00(dev); + kfree(ucb); +} + +static struct class ucb1x00_class = { + .name = "ucb1x00", + .release = ucb1x00_release, +}; + +int ucb1x00_register_driver(struct ucb1x00_driver *drv) +{ + struct ucb1x00 *ucb; + + INIT_LIST_HEAD(&drv->devs); + down(&ucb1x00_sem); + list_add(&drv->node, &ucb1x00_drivers); + list_for_each_entry(ucb, &ucb1x00_devices, node) { + ucb1x00_add_dev(ucb, drv); + } + up(&ucb1x00_sem); + return 0; +} + +void ucb1x00_unregister_driver(struct ucb1x00_driver *drv) +{ + struct list_head *n, *l; + + down(&ucb1x00_sem); + 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); + } + up(&ucb1x00_sem); +} + +static int ucb1x00_suspend(struct mcp *mcp, pm_message_t state) +{ + struct ucb1x00 *ucb = mcp_get_drvdata(mcp); + struct ucb1x00_dev *dev; + + down(&ucb1x00_sem); + list_for_each_entry(dev, &ucb->devs, dev_node) { + if (dev->drv->suspend) + dev->drv->suspend(dev, state); + } + up(&ucb1x00_sem); + return 0; +} + +static int ucb1x00_resume(struct mcp *mcp) +{ + struct ucb1x00 *ucb = mcp_get_drvdata(mcp); + struct ucb1x00_dev *dev; + + down(&ucb1x00_sem); + list_for_each_entry(dev, &ucb->devs, dev_node) { + if (dev->drv->resume) + dev->drv->resume(dev); + } + up(&ucb1x00_sem); + 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_class); + +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"); |