diff options
Diffstat (limited to 'drivers/mfd/mcp-core.c')
-rw-r--r-- | drivers/mfd/mcp-core.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/mfd/mcp-core.c b/drivers/mfd/mcp-core.c new file mode 100644 index 0000000000..2fa592c37c --- /dev/null +++ b/drivers/mfd/mcp-core.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/mfd/mcp-core.c + * + * Copyright (C) 2001 Russell King + * + * Generic MCP (Multimedia Communications Port) layer. All MCP locking + * is solely held within this file. + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/smp.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/mfd/mcp.h> + + +#define to_mcp(d) container_of(d, struct mcp, attached_device) +#define to_mcp_driver(d) container_of(d, struct mcp_driver, drv) + +static int mcp_bus_match(struct device *dev, struct device_driver *drv) +{ + return 1; +} + +static int mcp_bus_probe(struct device *dev) +{ + struct mcp *mcp = to_mcp(dev); + struct mcp_driver *drv = to_mcp_driver(dev->driver); + + return drv->probe(mcp); +} + +static void mcp_bus_remove(struct device *dev) +{ + struct mcp *mcp = to_mcp(dev); + struct mcp_driver *drv = to_mcp_driver(dev->driver); + + drv->remove(mcp); +} + +static struct bus_type mcp_bus_type = { + .name = "mcp", + .match = mcp_bus_match, + .probe = mcp_bus_probe, + .remove = mcp_bus_remove, +}; + +/** + * mcp_set_telecom_divisor - set the telecom divisor + * @mcp: MCP interface structure + * @div: SIB clock divisor + * + * Set the telecom divisor on the MCP interface. The resulting + * sample rate is SIBCLOCK/div. + */ +void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div) +{ + unsigned long flags; + + spin_lock_irqsave(&mcp->lock, flags); + mcp->ops->set_telecom_divisor(mcp, div); + spin_unlock_irqrestore(&mcp->lock, flags); +} +EXPORT_SYMBOL(mcp_set_telecom_divisor); + +/** + * mcp_set_audio_divisor - set the audio divisor + * @mcp: MCP interface structure + * @div: SIB clock divisor + * + * Set the audio divisor on the MCP interface. + */ +void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div) +{ + unsigned long flags; + + spin_lock_irqsave(&mcp->lock, flags); + mcp->ops->set_audio_divisor(mcp, div); + spin_unlock_irqrestore(&mcp->lock, flags); +} +EXPORT_SYMBOL(mcp_set_audio_divisor); + +/** + * mcp_reg_write - write a device register + * @mcp: MCP interface structure + * @reg: 4-bit register index + * @val: 16-bit data value + * + * Write a device register. The MCP interface must be enabled + * to prevent this function hanging. + */ +void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val) +{ + unsigned long flags; + + spin_lock_irqsave(&mcp->lock, flags); + mcp->ops->reg_write(mcp, reg, val); + spin_unlock_irqrestore(&mcp->lock, flags); +} +EXPORT_SYMBOL(mcp_reg_write); + +/** + * mcp_reg_read - read a device register + * @mcp: MCP interface structure + * @reg: 4-bit register index + * + * Read a device register and return its value. The MCP interface + * must be enabled to prevent this function hanging. + */ +unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg) +{ + unsigned long flags; + unsigned int val; + + spin_lock_irqsave(&mcp->lock, flags); + val = mcp->ops->reg_read(mcp, reg); + spin_unlock_irqrestore(&mcp->lock, flags); + + return val; +} +EXPORT_SYMBOL(mcp_reg_read); + +/** + * mcp_enable - enable the MCP interface + * @mcp: MCP interface to enable + * + * Enable the MCP interface. Each call to mcp_enable will need + * a corresponding call to mcp_disable to disable the interface. + */ +void mcp_enable(struct mcp *mcp) +{ + unsigned long flags; + + spin_lock_irqsave(&mcp->lock, flags); + if (mcp->use_count++ == 0) + mcp->ops->enable(mcp); + spin_unlock_irqrestore(&mcp->lock, flags); +} +EXPORT_SYMBOL(mcp_enable); + +/** + * mcp_disable - disable the MCP interface + * @mcp: MCP interface to disable + * + * Disable the MCP interface. The MCP interface will only be + * disabled once the number of calls to mcp_enable matches the + * number of calls to mcp_disable. + */ +void mcp_disable(struct mcp *mcp) +{ + unsigned long flags; + + spin_lock_irqsave(&mcp->lock, flags); + if (--mcp->use_count == 0) + mcp->ops->disable(mcp); + spin_unlock_irqrestore(&mcp->lock, flags); +} +EXPORT_SYMBOL(mcp_disable); + +static void mcp_release(struct device *dev) +{ + struct mcp *mcp = container_of(dev, struct mcp, attached_device); + + kfree(mcp); +} + +struct mcp *mcp_host_alloc(struct device *parent, size_t size) +{ + struct mcp *mcp; + + mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL); + if (mcp) { + spin_lock_init(&mcp->lock); + device_initialize(&mcp->attached_device); + mcp->attached_device.parent = parent; + mcp->attached_device.bus = &mcp_bus_type; + mcp->attached_device.dma_mask = parent->dma_mask; + mcp->attached_device.release = mcp_release; + } + return mcp; +} +EXPORT_SYMBOL(mcp_host_alloc); + +int mcp_host_add(struct mcp *mcp, void *pdata) +{ + mcp->attached_device.platform_data = pdata; + dev_set_name(&mcp->attached_device, "mcp0"); + return device_add(&mcp->attached_device); +} +EXPORT_SYMBOL(mcp_host_add); + +void mcp_host_del(struct mcp *mcp) +{ + device_del(&mcp->attached_device); +} +EXPORT_SYMBOL(mcp_host_del); + +void mcp_host_free(struct mcp *mcp) +{ + put_device(&mcp->attached_device); +} +EXPORT_SYMBOL(mcp_host_free); + +int mcp_driver_register(struct mcp_driver *mcpdrv) +{ + mcpdrv->drv.bus = &mcp_bus_type; + return driver_register(&mcpdrv->drv); +} +EXPORT_SYMBOL(mcp_driver_register); + +void mcp_driver_unregister(struct mcp_driver *mcpdrv) +{ + driver_unregister(&mcpdrv->drv); +} +EXPORT_SYMBOL(mcp_driver_unregister); + +static int __init mcp_init(void) +{ + return bus_register(&mcp_bus_type); +} + +static void __exit mcp_exit(void) +{ + bus_unregister(&mcp_bus_type); +} + +module_init(mcp_init); +module_exit(mcp_exit); + +MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); +MODULE_DESCRIPTION("Core multimedia communications port driver"); +MODULE_LICENSE("GPL"); |