drivers/mfd/kempld-core.c - maze/linux - Git at Google

 /*
  * Kontron PLD MFD core driver
  *
  * Copyright (c) 2010-2013 Kontron Europe GmbH
  * Author: Michael Brunner <michael.brunner@kontron.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License 2 as published
  * by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/platform_device.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/kempld.h>
 #include <linux/module.h>
 #include <linux/dmi.h>
 #include <linux/io.h>
 #include <linux/delay.h>

 #define MAX_ID_LEN 4
 static char force_device_id[MAX_ID_LEN + 1] = "";
 module_param_string(force_device_id, force_device_id, sizeof(force_device_id), 0);
 MODULE_PARM_DESC(force_device_id, "Override detected product");

 /*
  * Get hardware mutex to block firmware from accessing the pld.
  * It is possible for the firmware may hold the mutex for an extended length of
  * time. This function will block until access has been granted.
  */
 static void kempld_get_hardware_mutex(struct kempld_device_data *pld)
 {
 	/* The mutex bit will read 1 until access has been granted */
 	while (ioread8(pld->io_index) & KEMPLD_MUTEX_KEY)
 		msleep(1);
 }

 static void kempld_release_hardware_mutex(struct kempld_device_data *pld)
 {
 	/* The harware mutex is released when 1 is written to the mutex bit. */
 	iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
 }

 static int kempld_get_info_generic(struct kempld_device_data *pld)
 {
 	u16 version;
 	u8 spec;

 	kempld_get_mutex(pld);

 	version = kempld_read16(pld, KEMPLD_VERSION);
 	spec = kempld_read8(pld, KEMPLD_SPEC);
 	pld->info.buildnr = kempld_read16(pld, KEMPLD_BUILDNR);

 	pld->info.minor = KEMPLD_VERSION_GET_MINOR(version);
 	pld->info.major = KEMPLD_VERSION_GET_MAJOR(version);
 	pld->info.number = KEMPLD_VERSION_GET_NUMBER(version);
 	pld->info.type = KEMPLD_VERSION_GET_TYPE(version);

 	if (spec == 0xff) {
 		pld->info.spec_minor = 0;
 		pld->info.spec_major = 1;
 	} else {
 		pld->info.spec_minor = KEMPLD_SPEC_GET_MINOR(spec);
 		pld->info.spec_major = KEMPLD_SPEC_GET_MAJOR(spec);
 	}

 	if (pld->info.spec_major > 0)
 		pld->feature_mask = kempld_read16(pld, KEMPLD_FEATURE);
 	else
 		pld->feature_mask = 0;

 	kempld_release_mutex(pld);

 	return 0;
 }

 enum kempld_cells {
 	KEMPLD_I2C = 0,
 	KEMPLD_WDT,
 	KEMPLD_GPIO,
 	KEMPLD_UART,
 };

 static struct mfd_cell kempld_devs[] = {
 	[KEMPLD_I2C] = {
 		.name = "kempld-i2c",
 	},
 	[KEMPLD_WDT] = {
 		.name = "kempld-wdt",
 	},
 	[KEMPLD_GPIO] = {
 		.name = "kempld-gpio",
 	},
 	[KEMPLD_UART] = {
 		.name = "kempld-uart",
 	},
 };

 #define KEMPLD_MAX_DEVS	ARRAY_SIZE(kempld_devs)

 static int kempld_register_cells_generic(struct kempld_device_data *pld)
 {
 	struct mfd_cell devs[KEMPLD_MAX_DEVS];
 	int i = 0;

 	if (pld->feature_mask & KEMPLD_FEATURE_BIT_I2C)
 		devs[i++] = kempld_devs[KEMPLD_I2C];

 	if (pld->feature_mask & KEMPLD_FEATURE_BIT_WATCHDOG)
 		devs[i++] = kempld_devs[KEMPLD_WDT];

 	if (pld->feature_mask & KEMPLD_FEATURE_BIT_GPIO)
 		devs[i++] = kempld_devs[KEMPLD_GPIO];

 	if (pld->feature_mask & KEMPLD_FEATURE_MASK_UART)
 		devs[i++] = kempld_devs[KEMPLD_UART];

 	return mfd_add_devices(pld->dev, -1, devs, i, NULL, 0, NULL);
 }

 static struct resource kempld_ioresource = {
 	.start	= KEMPLD_IOINDEX,
 	.end	= KEMPLD_IODATA,
 	.flags	= IORESOURCE_IO,
 };

 static const struct kempld_platform_data kempld_platform_data_generic = {
 	.pld_clock		= KEMPLD_CLK,
 	.ioresource		= &kempld_ioresource,
 	.get_hardware_mutex	= kempld_get_hardware_mutex,
 	.release_hardware_mutex	= kempld_release_hardware_mutex,
 	.get_info		= kempld_get_info_generic,
 	.register_cells		= kempld_register_cells_generic,
 };

 static struct platform_device *kempld_pdev;

 static int kempld_create_platform_device(const struct dmi_system_id *id)
 {
 	struct kempld_platform_data *pdata = id->driver_data;
 	int ret;

 	kempld_pdev = platform_device_alloc("kempld", -1);
 	if (!kempld_pdev)
 		return -ENOMEM;

 	ret = platform_device_add_data(kempld_pdev, pdata, sizeof(*pdata));
 	if (ret)
 		goto err;

 	ret = platform_device_add_resources(kempld_pdev, pdata->ioresource, 1);
 	if (ret)
 		goto err;

 	ret = platform_device_add(kempld_pdev);
 	if (ret)
 		goto err;

 	return 0;
 err:
 	platform_device_put(kempld_pdev);
 	return ret;
 }

 /**
  * kempld_read8 - read 8 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 u8 kempld_read8(struct kempld_device_data *pld, u8 index)
 {
 	iowrite8(index, pld->io_index);
 	return ioread8(pld->io_data);
 }
 EXPORT_SYMBOL_GPL(kempld_read8);

 /**
  * kempld_write8 - write 8 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  * @data: new register value
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data)
 {
 	iowrite8(index, pld->io_index);
 	iowrite8(data, pld->io_data);
 }
 EXPORT_SYMBOL_GPL(kempld_write8);

 /**
  * kempld_read16 - read 16 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 u16 kempld_read16(struct kempld_device_data *pld, u8 index)
 {
 	return kempld_read8(pld, index) | kempld_read8(pld, index + 1) << 8;
 }
 EXPORT_SYMBOL_GPL(kempld_read16);

 /**
  * kempld_write16 - write 16 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  * @data: new register value
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data)
 {
 	kempld_write8(pld, index, (u8)data);
 	kempld_write8(pld, index + 1, (u8)(data >> 8));
 }
 EXPORT_SYMBOL_GPL(kempld_write16);

 /**
  * kempld_read32 - read 32 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 u32 kempld_read32(struct kempld_device_data *pld, u8 index)
 {
 	return kempld_read16(pld, index) | kempld_read16(pld, index + 2) << 16;
 }
 EXPORT_SYMBOL_GPL(kempld_read32);

 /**
  * kempld_write32 - write 32 bit register
  * @pld: kempld_device_data structure describing the PLD
  * @index: register index on the chip
  * @data: new register value
  *
  * kempld_get_mutex must be called prior to calling this function.
  */
 void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data)
 {
 	kempld_write16(pld, index, (u16)data);
 	kempld_write16(pld, index + 2, (u16)(data >> 16));
 }
 EXPORT_SYMBOL_GPL(kempld_write32);

 /**
  * kempld_get_mutex - acquire PLD mutex
  * @pld: kempld_device_data structure describing the PLD
  */
 void kempld_get_mutex(struct kempld_device_data *pld)
 {
 	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

 	mutex_lock(&pld->lock);
 	pdata->get_hardware_mutex(pld);
 }
 EXPORT_SYMBOL_GPL(kempld_get_mutex);

 /**
  * kempld_release_mutex - release PLD mutex
  * @pld: kempld_device_data structure describing the PLD
  */
 void kempld_release_mutex(struct kempld_device_data *pld)
 {
 	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

 	pdata->release_hardware_mutex(pld);
 	mutex_unlock(&pld->lock);
 }
 EXPORT_SYMBOL_GPL(kempld_release_mutex);

 /**
  * kempld_get_info - update device specific information
  * @pld: kempld_device_data structure describing the PLD
  *
  * This function calls the configured board specific kempld_get_info_XXXX
  * function which is responsible for gathering information about the specific
  * hardware. The information is then stored within the pld structure.
  */
 static int kempld_get_info(struct kempld_device_data *pld)
 {
 	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

 	return pdata->get_info(pld);
 }

 /*
  * kempld_register_cells - register cell drivers
  *
  * This function registers cell drivers for the detected hardware by calling
  * the configured kempld_register_cells_XXXX function which is responsible
  * to detect and register the needed cell drivers.
  */
 static int kempld_register_cells(struct kempld_device_data *pld)
 {
 	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

 	return pdata->register_cells(pld);
 }

 static int kempld_detect_device(struct kempld_device_data *pld)
 {
 	char *version_type;
 	u8 index_reg;
 	int ret;

 	mutex_lock(&pld->lock);

 	/* Check for empty IO space */
 	index_reg = ioread8(pld->io_index);
 	if (index_reg == 0xff && ioread8(pld->io_data) == 0xff) {
 		mutex_unlock(&pld->lock);
 		return -ENODEV;
 	}

 	/* Release hardware mutex if acquired */
 	if (!(index_reg & KEMPLD_MUTEX_KEY)) {
 		iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
 		/* PXT and COMe-cPC2 boards may require a second release */
 		iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
 	}

 	mutex_unlock(&pld->lock);

 	ret = kempld_get_info(pld);
 	if (ret)
 		return ret;

 	switch (pld->info.type) {
 	case 0:
 		version_type = "release";
 		break;
 	case 1:
 		version_type = "debug";
 		break;
 	case 2:
 		version_type = "custom";
 		break;
 	default:
 		version_type = "unspecified";
 	}

 	dev_info(pld->dev, "Found Kontron PLD %d\n", pld->info.number);
 	dev_info(pld->dev, "%s version %d.%d build %d, specification %d.%d\n",
 		 version_type, pld->info.major, pld->info.minor,
 		 pld->info.buildnr, pld->info.spec_major,
 		 pld->info.spec_minor);

 	return kempld_register_cells(pld);
 }

 static int kempld_probe(struct platform_device *pdev)
 {
 	struct kempld_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct device *dev = &pdev->dev;
 	struct kempld_device_data *pld;
 	struct resource *ioport;
 	int ret;

 	pld = devm_kzalloc(dev, sizeof(*pld), GFP_KERNEL);
 	if (!pld)
 		return -ENOMEM;

 	ioport = platform_get_resource(pdev, IORESOURCE_IO, 0);
 	if (!ioport)
 		return -EINVAL;

 	pld->io_base = devm_ioport_map(dev, ioport->start,
 					ioport->end - ioport->start);
 	if (!pld->io_base)
 		return -ENOMEM;

 	pld->io_index = pld->io_base;
 	pld->io_data = pld->io_base + 1;
 	pld->pld_clock = pdata->pld_clock;
 	pld->dev = dev;

 	mutex_init(&pld->lock);
 	platform_set_drvdata(pdev, pld);

 	ret = kempld_detect_device(pld);
 	if (ret)
 		return ret;

 	return 0;
 }

 static int kempld_remove(struct platform_device *pdev)
 {
 	struct kempld_device_data *pld = platform_get_drvdata(pdev);
 	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

 	mfd_remove_devices(&pdev->dev);
 	pdata->release_hardware_mutex(pld);

 	return 0;
 }

 static struct platform_driver kempld_driver = {
 	.driver		= {
 		.name	= "kempld",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= kempld_probe,
 	.remove		= kempld_remove,
 };

 static struct dmi_system_id __initdata kempld_dmi_table[] = {
 	{
 		.ident = "BHL6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bHL6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	},
 	{
 		.ident = "CCR2",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CCR6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHL6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cHL6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR2",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR2",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR2",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CHR6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CNTG",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-PC"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CNTG",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-bPC2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CNTX",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "PXT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "CVV6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cBT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "FRI2",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BIOS_VERSION, "FRI2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "FRI2",
 		.matches = {
 			DMI_MATCH(DMI_PRODUCT_NAME, "Fish River Island II"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "MBR1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "ETX-OH"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "MVV1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-mBT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "NTC1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-TT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "NTC1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "nETXe-TT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "NTC1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-mTT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "NUP1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-mCT"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "UNP1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-DC"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "UNP1",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cDC2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "UNTG",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-PC"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "UNTG",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cPC2"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	}, {
 		.ident = "UUP6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cCT6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	},
 	{
 		.ident = "UTH6",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
 			DMI_MATCH(DMI_BOARD_NAME, "COMe-cTH6"),
 		},
 		.driver_data = (void *)&kempld_platform_data_generic,
 		.callback = kempld_create_platform_device,
 	},
 	{}
 };
 MODULE_DEVICE_TABLE(dmi, kempld_dmi_table);

 static int __init kempld_init(void)
 {
 	const struct dmi_system_id *id;
 	int ret;

 	if (force_device_id[0]) {
 		for (id = kempld_dmi_table; id->matches[0].slot != DMI_NONE; id++)
 			if (strstr(id->ident, force_device_id))
 				if (id->callback && id->callback(id))
 					break;
 		if (id->matches[0].slot == DMI_NONE)
 			return -ENODEV;
 	} else {
 		if (!dmi_check_system(kempld_dmi_table))
 			return -ENODEV;
 	}

 	ret = platform_driver_register(&kempld_driver);
 	if (ret)
 		return ret;

 	return 0;
 }

 static void __exit kempld_exit(void)
 {
 	if (kempld_pdev)
 		platform_device_unregister(kempld_pdev);

 	platform_driver_unregister(&kempld_driver);
 }

 module_init(kempld_init);
 module_exit(kempld_exit);

 MODULE_DESCRIPTION("KEM PLD Core Driver");
 MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:kempld-core");
	/*
	* Kontron PLD MFD core driver
	*
	* Copyright (c) 2010-2013 Kontron Europe GmbH
	* Author: Michael Brunner <michael.brunner@kontron.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License 2 as published
	* by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/platform_device.h>
	#include <linux/mfd/core.h>
	#include <linux/mfd/kempld.h>
	#include <linux/module.h>
	#include <linux/dmi.h>
	#include <linux/io.h>
	#include <linux/delay.h>

	#define MAX_ID_LEN 4
	static char force_device_id[MAX_ID_LEN + 1] = "";
	module_param_string(force_device_id, force_device_id, sizeof(force_device_id), 0);
	MODULE_PARM_DESC(force_device_id, "Override detected product");

	/*
	* Get hardware mutex to block firmware from accessing the pld.
	* It is possible for the firmware may hold the mutex for an extended length of
	* time. This function will block until access has been granted.
	*/
	static void kempld_get_hardware_mutex(struct kempld_device_data *pld)
	{
	/* The mutex bit will read 1 until access has been granted */
	while (ioread8(pld->io_index) & KEMPLD_MUTEX_KEY)
	msleep(1);
	}

	static void kempld_release_hardware_mutex(struct kempld_device_data *pld)
	{
	/* The harware mutex is released when 1 is written to the mutex bit. */
	iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
	}

	static int kempld_get_info_generic(struct kempld_device_data *pld)
	{
	u16 version;
	u8 spec;

	kempld_get_mutex(pld);

	version = kempld_read16(pld, KEMPLD_VERSION);
	spec = kempld_read8(pld, KEMPLD_SPEC);
	pld->info.buildnr = kempld_read16(pld, KEMPLD_BUILDNR);

	pld->info.minor = KEMPLD_VERSION_GET_MINOR(version);
	pld->info.major = KEMPLD_VERSION_GET_MAJOR(version);
	pld->info.number = KEMPLD_VERSION_GET_NUMBER(version);
	pld->info.type = KEMPLD_VERSION_GET_TYPE(version);

	if (spec == 0xff) {
	pld->info.spec_minor = 0;
	pld->info.spec_major = 1;
	} else {
	pld->info.spec_minor = KEMPLD_SPEC_GET_MINOR(spec);
	pld->info.spec_major = KEMPLD_SPEC_GET_MAJOR(spec);
	}

	if (pld->info.spec_major > 0)
	pld->feature_mask = kempld_read16(pld, KEMPLD_FEATURE);
	else
	pld->feature_mask = 0;

	kempld_release_mutex(pld);

	return 0;
	}

	enum kempld_cells {
	KEMPLD_I2C = 0,
	KEMPLD_WDT,
	KEMPLD_GPIO,
	KEMPLD_UART,
	};

	static struct mfd_cell kempld_devs[] = {
	[KEMPLD_I2C] = {
	.name = "kempld-i2c",
	},
	[KEMPLD_WDT] = {
	.name = "kempld-wdt",
	},
	[KEMPLD_GPIO] = {
	.name = "kempld-gpio",
	},
	[KEMPLD_UART] = {
	.name = "kempld-uart",
	},
	};

	#define KEMPLD_MAX_DEVS ARRAY_SIZE(kempld_devs)

	static int kempld_register_cells_generic(struct kempld_device_data *pld)
	{
	struct mfd_cell devs[KEMPLD_MAX_DEVS];
	int i = 0;

	if (pld->feature_mask & KEMPLD_FEATURE_BIT_I2C)
	devs[i++] = kempld_devs[KEMPLD_I2C];

	if (pld->feature_mask & KEMPLD_FEATURE_BIT_WATCHDOG)
	devs[i++] = kempld_devs[KEMPLD_WDT];

	if (pld->feature_mask & KEMPLD_FEATURE_BIT_GPIO)
	devs[i++] = kempld_devs[KEMPLD_GPIO];

	if (pld->feature_mask & KEMPLD_FEATURE_MASK_UART)
	devs[i++] = kempld_devs[KEMPLD_UART];

	return mfd_add_devices(pld->dev, -1, devs, i, NULL, 0, NULL);
	}

	static struct resource kempld_ioresource = {
	.start = KEMPLD_IOINDEX,
	.end = KEMPLD_IODATA,
	.flags = IORESOURCE_IO,
	};

	static const struct kempld_platform_data kempld_platform_data_generic = {
	.pld_clock = KEMPLD_CLK,
	.ioresource = &kempld_ioresource,
	.get_hardware_mutex = kempld_get_hardware_mutex,
	.release_hardware_mutex = kempld_release_hardware_mutex,
	.get_info = kempld_get_info_generic,
	.register_cells = kempld_register_cells_generic,
	};

	static struct platform_device *kempld_pdev;

	static int kempld_create_platform_device(const struct dmi_system_id *id)
	{
	struct kempld_platform_data *pdata = id->driver_data;
	int ret;

	kempld_pdev = platform_device_alloc("kempld", -1);
	if (!kempld_pdev)
	return -ENOMEM;

	ret = platform_device_add_data(kempld_pdev, pdata, sizeof(*pdata));
	if (ret)
	goto err;

	ret = platform_device_add_resources(kempld_pdev, pdata->ioresource, 1);
	if (ret)
	goto err;

	ret = platform_device_add(kempld_pdev);
	if (ret)
	goto err;

	return 0;
	err:
	platform_device_put(kempld_pdev);
	return ret;
	}

	/**
	* kempld_read8 - read 8 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	u8 kempld_read8(struct kempld_device_data *pld, u8 index)
	{
	iowrite8(index, pld->io_index);
	return ioread8(pld->io_data);
	}
	EXPORT_SYMBOL_GPL(kempld_read8);

	/**
	* kempld_write8 - write 8 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	* @data: new register value
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data)
	{
	iowrite8(index, pld->io_index);
	iowrite8(data, pld->io_data);
	}
	EXPORT_SYMBOL_GPL(kempld_write8);

	/**
	* kempld_read16 - read 16 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	u16 kempld_read16(struct kempld_device_data *pld, u8 index)
	{
	return kempld_read8(pld, index) \| kempld_read8(pld, index + 1) << 8;
	}
	EXPORT_SYMBOL_GPL(kempld_read16);

	/**
	* kempld_write16 - write 16 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	* @data: new register value
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data)
	{
	kempld_write8(pld, index, (u8)data);
	kempld_write8(pld, index + 1, (u8)(data >> 8));
	}
	EXPORT_SYMBOL_GPL(kempld_write16);

	/**
	* kempld_read32 - read 32 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	u32 kempld_read32(struct kempld_device_data *pld, u8 index)
	{
	return kempld_read16(pld, index) \| kempld_read16(pld, index + 2) << 16;
	}
	EXPORT_SYMBOL_GPL(kempld_read32);

	/**
	* kempld_write32 - write 32 bit register
	* @pld: kempld_device_data structure describing the PLD
	* @index: register index on the chip
	* @data: new register value
	*
	* kempld_get_mutex must be called prior to calling this function.
	*/
	void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data)
	{
	kempld_write16(pld, index, (u16)data);
	kempld_write16(pld, index + 2, (u16)(data >> 16));
	}
	EXPORT_SYMBOL_GPL(kempld_write32);

	/**
	* kempld_get_mutex - acquire PLD mutex
	* @pld: kempld_device_data structure describing the PLD
	*/
	void kempld_get_mutex(struct kempld_device_data *pld)
	{
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

	mutex_lock(&pld->lock);
	pdata->get_hardware_mutex(pld);
	}
	EXPORT_SYMBOL_GPL(kempld_get_mutex);

	/**
	* kempld_release_mutex - release PLD mutex
	* @pld: kempld_device_data structure describing the PLD
	*/
	void kempld_release_mutex(struct kempld_device_data *pld)
	{
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

	pdata->release_hardware_mutex(pld);
	mutex_unlock(&pld->lock);
	}
	EXPORT_SYMBOL_GPL(kempld_release_mutex);

	/**
	* kempld_get_info - update device specific information
	* @pld: kempld_device_data structure describing the PLD
	*
	* This function calls the configured board specific kempld_get_info_XXXX
	* function which is responsible for gathering information about the specific
	* hardware. The information is then stored within the pld structure.
	*/
	static int kempld_get_info(struct kempld_device_data *pld)
	{
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

	return pdata->get_info(pld);
	}

	/*
	* kempld_register_cells - register cell drivers
	*
	* This function registers cell drivers for the detected hardware by calling
	* the configured kempld_register_cells_XXXX function which is responsible
	* to detect and register the needed cell drivers.
	*/
	static int kempld_register_cells(struct kempld_device_data *pld)
	{
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

	return pdata->register_cells(pld);
	}

	static int kempld_detect_device(struct kempld_device_data *pld)
	{
	char *version_type;
	u8 index_reg;
	int ret;

	mutex_lock(&pld->lock);

	/* Check for empty IO space */
	index_reg = ioread8(pld->io_index);
	if (index_reg == 0xff && ioread8(pld->io_data) == 0xff) {
	mutex_unlock(&pld->lock);
	return -ENODEV;
	}

	/* Release hardware mutex if acquired */
	if (!(index_reg & KEMPLD_MUTEX_KEY)) {
	iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
	/* PXT and COMe-cPC2 boards may require a second release */
	iowrite8(KEMPLD_MUTEX_KEY, pld->io_index);
	}

	mutex_unlock(&pld->lock);

	ret = kempld_get_info(pld);
	if (ret)
	return ret;

	switch (pld->info.type) {
	case 0:
	version_type = "release";
	break;
	case 1:
	version_type = "debug";
	break;
	case 2:
	version_type = "custom";
	break;
	default:
	version_type = "unspecified";
	}

	dev_info(pld->dev, "Found Kontron PLD %d\n", pld->info.number);
	dev_info(pld->dev, "%s version %d.%d build %d, specification %d.%d\n",
	version_type, pld->info.major, pld->info.minor,
	pld->info.buildnr, pld->info.spec_major,
	pld->info.spec_minor);

	return kempld_register_cells(pld);
	}

	static int kempld_probe(struct platform_device *pdev)
	{
	struct kempld_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct device *dev = &pdev->dev;
	struct kempld_device_data *pld;
	struct resource *ioport;
	int ret;

	pld = devm_kzalloc(dev, sizeof(*pld), GFP_KERNEL);
	if (!pld)
	return -ENOMEM;

	ioport = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!ioport)
	return -EINVAL;

	pld->io_base = devm_ioport_map(dev, ioport->start,
	ioport->end - ioport->start);
	if (!pld->io_base)
	return -ENOMEM;

	pld->io_index = pld->io_base;
	pld->io_data = pld->io_base + 1;
	pld->pld_clock = pdata->pld_clock;
	pld->dev = dev;

	mutex_init(&pld->lock);
	platform_set_drvdata(pdev, pld);

	ret = kempld_detect_device(pld);
	if (ret)
	return ret;

	return 0;
	}

	static int kempld_remove(struct platform_device *pdev)
	{
	struct kempld_device_data *pld = platform_get_drvdata(pdev);
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);

	mfd_remove_devices(&pdev->dev);
	pdata->release_hardware_mutex(pld);

	return 0;
	}

	static struct platform_driver kempld_driver = {
	.driver = {
	.name = "kempld",
	.owner = THIS_MODULE,
	},
	.probe = kempld_probe,
	.remove = kempld_remove,
	};

	static struct dmi_system_id __initdata kempld_dmi_table[] = {
	{
	.ident = "BHL6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bHL6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	},
	{
	.ident = "CCR2",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CCR6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHL6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cHL6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR2",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR2",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR2",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CHR6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CNTG",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-PC"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CNTG",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-bPC2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CNTX",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "PXT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "CVV6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cBT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "FRI2",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BIOS_VERSION, "FRI2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "FRI2",
	.matches = {
	DMI_MATCH(DMI_PRODUCT_NAME, "Fish River Island II"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "MBR1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "ETX-OH"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "MVV1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-mBT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "NTC1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-TT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "NTC1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "nETXe-TT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "NTC1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-mTT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "NUP1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-mCT"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "UNP1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-DC"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "UNP1",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cDC2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "UNTG",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-PC"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "UNTG",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cPC2"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	}, {
	.ident = "UUP6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cCT6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	},
	{
	.ident = "UTH6",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
	DMI_MATCH(DMI_BOARD_NAME, "COMe-cTH6"),
	},
	.driver_data = (void *)&kempld_platform_data_generic,
	.callback = kempld_create_platform_device,
	},
	{}
	};
	MODULE_DEVICE_TABLE(dmi, kempld_dmi_table);

	static int __init kempld_init(void)
	{
	const struct dmi_system_id *id;
	int ret;

	if (force_device_id[0]) {
	for (id = kempld_dmi_table; id->matches[0].slot != DMI_NONE; id++)
	if (strstr(id->ident, force_device_id))
	if (id->callback && id->callback(id))
	break;
	if (id->matches[0].slot == DMI_NONE)
	return -ENODEV;
	} else {
	if (!dmi_check_system(kempld_dmi_table))
	return -ENODEV;
	}

	ret = platform_driver_register(&kempld_driver);
	if (ret)
	return ret;

	return 0;
	}

	static void __exit kempld_exit(void)
	{
	if (kempld_pdev)
	platform_device_unregister(kempld_pdev);

	platform_driver_unregister(&kempld_driver);
	}

	module_init(kempld_init);
	module_exit(kempld_exit);

	MODULE_DESCRIPTION("KEM PLD Core Driver");
	MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:kempld-core");