drivers/mfd/sta2x11-mfd.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * STA2x11 mfd for GPIO, SCTL and APBREG
  *
  * Copyright (c) 2009-2011 Wind River Systems, Inc.
  * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini, Davide Ciminaghi)
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/export.h>
 #include <linux/spinlock.h>
 #include <linux/errno.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/pci.h>
 #include <linux/seq_file.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/sta2x11-mfd.h>
 #include <linux/regmap.h>

 #include <asm/sta2x11.h>

 static inline int __reg_within_range(unsigned int r,
 				     unsigned int start,
 				     unsigned int end)
 {
 	return ((r >= start) && (r <= end));
 }

 /* This describes STA2X11 MFD chip for us, we may have several */
 struct sta2x11_mfd {
 	struct sta2x11_instance *instance;
 	struct regmap *regmap[sta2x11_n_mfd_plat_devs];
 	spinlock_t lock[sta2x11_n_mfd_plat_devs];
 	struct list_head list;
 	void __iomem *regs[sta2x11_n_mfd_plat_devs];
 };

 static LIST_HEAD(sta2x11_mfd_list);

 /* Three functions to act on the list */
 static struct sta2x11_mfd *sta2x11_mfd_find(struct pci_dev *pdev)
 {
 	struct sta2x11_instance *instance;
 	struct sta2x11_mfd *mfd;

 	if (!pdev && !list_empty(&sta2x11_mfd_list)) {
 		pr_warn("%s: Unspecified device, using first instance\n",
 			__func__);
 		return list_entry(sta2x11_mfd_list.next,
 				  struct sta2x11_mfd, list);
 	}

 	instance = sta2x11_get_instance(pdev);
 	if (!instance)
 		return NULL;
 	list_for_each_entry(mfd, &sta2x11_mfd_list, list) {
 		if (mfd->instance == instance)
 			return mfd;
 	}
 	return NULL;
 }

 static int sta2x11_mfd_add(struct pci_dev *pdev, gfp_t flags)
 {
 	int i;
 	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
 	struct sta2x11_instance *instance;

 	if (mfd)
 		return -EBUSY;
 	instance = sta2x11_get_instance(pdev);
 	if (!instance)
 		return -EINVAL;
 	mfd = kzalloc(sizeof(*mfd), flags);
 	if (!mfd)
 		return -ENOMEM;
 	INIT_LIST_HEAD(&mfd->list);
 	for (i = 0; i < ARRAY_SIZE(mfd->lock); i++)
 		spin_lock_init(&mfd->lock[i]);
 	mfd->instance = instance;
 	list_add(&mfd->list, &sta2x11_mfd_list);
 	return 0;
 }

 /* This function is exported and is not expected to fail */
 u32 __sta2x11_mfd_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val,
 		       enum sta2x11_mfd_plat_dev index)
 {
 	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
 	u32 r;
 	unsigned long flags;
 	void __iomem *regs;

 	if (!mfd) {
 		dev_warn(&pdev->dev, ": can't access sctl regs\n");
 		return 0;
 	}

 	regs = mfd->regs[index];
 	if (!regs) {
 		dev_warn(&pdev->dev, ": system ctl not initialized\n");
 		return 0;
 	}
 	spin_lock_irqsave(&mfd->lock[index], flags);
 	r = readl(regs + reg);
 	r &= ~mask;
 	r |= val;
 	if (mask)
 		writel(r, regs + reg);
 	spin_unlock_irqrestore(&mfd->lock[index], flags);
 	return r;
 }
 EXPORT_SYMBOL(__sta2x11_mfd_mask);

 int sta2x11_mfd_get_regs_data(struct platform_device *dev,
 			      enum sta2x11_mfd_plat_dev index,
 			      void __iomem **regs,
 			      spinlock_t **lock)
 {
 	struct pci_dev *pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev);
 	struct sta2x11_mfd *mfd;

 	if (!pdev)
 		return -ENODEV;
 	mfd = sta2x11_mfd_find(pdev);
 	if (!mfd)
 		return -ENODEV;
 	if (index >= sta2x11_n_mfd_plat_devs)
 		return -ENODEV;
 	*regs = mfd->regs[index];
 	*lock = &mfd->lock[index];
 	pr_debug("%s %d *regs = %p\n", __func__, __LINE__, *regs);
 	return *regs ? 0 : -ENODEV;
 }
 EXPORT_SYMBOL(sta2x11_mfd_get_regs_data);

 /*
  * Special sta2x11-mfd regmap lock/unlock functions
  */

 static void sta2x11_regmap_lock(void *__lock)
 {
 	spinlock_t *lock = __lock;
 	spin_lock(lock);
 }

 static void sta2x11_regmap_unlock(void *__lock)
 {
 	spinlock_t *lock = __lock;
 	spin_unlock(lock);
 }

 /* OTP (one time programmable registers do not require locking */
 static void sta2x11_regmap_nolock(void *__lock)
 {
 }

 static const char *sta2x11_mfd_names[sta2x11_n_mfd_plat_devs] = {
 	[sta2x11_sctl] = STA2X11_MFD_SCTL_NAME,
 	[sta2x11_apbreg] = STA2X11_MFD_APBREG_NAME,
 	[sta2x11_apb_soc_regs] = STA2X11_MFD_APB_SOC_REGS_NAME,
 	[sta2x11_scr] = STA2X11_MFD_SCR_NAME,
 };

 static bool sta2x11_sctl_writeable_reg(struct device *dev, unsigned int reg)
 {
 	return !__reg_within_range(reg, SCTL_SCPCIECSBRST, SCTL_SCRSTSTA);
 }

 static struct regmap_config sta2x11_sctl_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.lock = sta2x11_regmap_lock,
 	.unlock = sta2x11_regmap_unlock,
 	.max_register = SCTL_SCRSTSTA,
 	.writeable_reg = sta2x11_sctl_writeable_reg,
 };

 static bool sta2x11_scr_readable_reg(struct device *dev, unsigned int reg)
 {
 	return (reg == STA2X11_SECR_CR) ||
 		__reg_within_range(reg, STA2X11_SECR_FVR0, STA2X11_SECR_FVR1);
 }

 static bool sta2x11_scr_writeable_reg(struct device *dev, unsigned int reg)
 {
 	return false;
 }

 static struct regmap_config sta2x11_scr_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.lock = sta2x11_regmap_nolock,
 	.unlock = sta2x11_regmap_nolock,
 	.max_register = STA2X11_SECR_FVR1,
 	.readable_reg = sta2x11_scr_readable_reg,
 	.writeable_reg = sta2x11_scr_writeable_reg,
 };

 static bool sta2x11_apbreg_readable_reg(struct device *dev, unsigned int reg)
 {
 	/* Two blocks (CAN and MLB, SARAC) 0x100 bytes apart */
 	if (reg >= APBREG_BSR_SARAC)
 		reg -= APBREG_BSR_SARAC;
 	switch (reg) {
 	case APBREG_BSR:
 	case APBREG_PAER:
 	case APBREG_PWAC:
 	case APBREG_PRAC:
 	case APBREG_PCG:
 	case APBREG_PUR:
 	case APBREG_EMU_PCG:
 		return true;
 	default:
 		return false;
 	}
 }

 static bool sta2x11_apbreg_writeable_reg(struct device *dev, unsigned int reg)
 {
 	if (reg >= APBREG_BSR_SARAC)
 		reg -= APBREG_BSR_SARAC;
 	if (!sta2x11_apbreg_readable_reg(dev, reg))
 		return false;
 	return reg != APBREG_PAER;
 }

 static struct regmap_config sta2x11_apbreg_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.lock = sta2x11_regmap_lock,
 	.unlock = sta2x11_regmap_unlock,
 	.max_register = APBREG_EMU_PCG_SARAC,
 	.readable_reg = sta2x11_apbreg_readable_reg,
 	.writeable_reg = sta2x11_apbreg_writeable_reg,
 };

 static bool sta2x11_apb_soc_regs_readable_reg(struct device *dev,
 					      unsigned int reg)
 {
 	return reg <= PCIE_SoC_INT_ROUTER_STATUS3_REG ||
 		__reg_within_range(reg, DMA_IP_CTRL_REG, SPARE3_RESERVED) ||
 		__reg_within_range(reg, MASTER_LOCK_REG,
 				   SYSTEM_CONFIG_STATUS_REG) ||
 		reg == MSP_CLK_CTRL_REG ||
 		__reg_within_range(reg, COMPENSATION_REG1, TEST_CTL_REG);
 }

 static bool sta2x11_apb_soc_regs_writeable_reg(struct device *dev,
 					       unsigned int reg)
 {
 	if (!sta2x11_apb_soc_regs_readable_reg(dev, reg))
 		return false;
 	switch (reg) {
 	case PCIE_COMMON_CLOCK_CONFIG_0_4_0:
 	case SYSTEM_CONFIG_STATUS_REG:
 	case COMPENSATION_REG1:
 	case PCIE_SoC_INT_ROUTER_STATUS0_REG...PCIE_SoC_INT_ROUTER_STATUS3_REG:
 	case PCIE_PM_STATUS_0_PORT_0_4...PCIE_PM_STATUS_7_0_EP4:
 		return false;
 	default:
 		return true;
 	}
 }

 static struct regmap_config sta2x11_apb_soc_regs_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.lock = sta2x11_regmap_lock,
 	.unlock = sta2x11_regmap_unlock,
 	.max_register = TEST_CTL_REG,
 	.readable_reg = sta2x11_apb_soc_regs_readable_reg,
 	.writeable_reg = sta2x11_apb_soc_regs_writeable_reg,
 };

 static struct regmap_config *
 sta2x11_mfd_regmap_configs[sta2x11_n_mfd_plat_devs] = {
 	[sta2x11_sctl] = &sta2x11_sctl_regmap_config,
 	[sta2x11_apbreg] = &sta2x11_apbreg_regmap_config,
 	[sta2x11_apb_soc_regs] = &sta2x11_apb_soc_regs_regmap_config,
 	[sta2x11_scr] = &sta2x11_scr_regmap_config,
 };

 /* Probe for the four platform devices */

 static int sta2x11_mfd_platform_probe(struct platform_device *dev,
 				      enum sta2x11_mfd_plat_dev index)
 {
 	struct pci_dev **pdev;
 	struct sta2x11_mfd *mfd;
 	struct resource *res;
 	const char *name = sta2x11_mfd_names[index];
 	struct regmap_config *regmap_config = sta2x11_mfd_regmap_configs[index];

 	pdev = dev_get_platdata(&dev->dev);
 	mfd = sta2x11_mfd_find(*pdev);
 	if (!mfd)
 		return -ENODEV;
 	if (!regmap_config)
 		return -ENODEV;

 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENOMEM;

 	if (!request_mem_region(res->start, resource_size(res), name))
 		return -EBUSY;

 	mfd->regs[index] = ioremap(res->start, resource_size(res));
 	if (!mfd->regs[index]) {
 		release_mem_region(res->start, resource_size(res));
 		return -ENOMEM;
 	}
 	regmap_config->lock_arg = &mfd->lock;
 	/*
 	   No caching, registers could be reached both via regmap and via
 	   void __iomem *
 	*/
 	regmap_config->cache_type = REGCACHE_NONE;
 	mfd->regmap[index] = devm_regmap_init_mmio(&dev->dev, mfd->regs[index],
 						   regmap_config);
 	WARN_ON(IS_ERR(mfd->regmap[index]));

 	return 0;
 }

 static int sta2x11_sctl_probe(struct platform_device *dev)
 {
 	return sta2x11_mfd_platform_probe(dev, sta2x11_sctl);
 }

 static int sta2x11_apbreg_probe(struct platform_device *dev)
 {
 	return sta2x11_mfd_platform_probe(dev, sta2x11_apbreg);
 }

 static int sta2x11_apb_soc_regs_probe(struct platform_device *dev)
 {
 	return sta2x11_mfd_platform_probe(dev, sta2x11_apb_soc_regs);
 }

 static int sta2x11_scr_probe(struct platform_device *dev)
 {
 	return sta2x11_mfd_platform_probe(dev, sta2x11_scr);
 }

 /* The three platform drivers */
 static struct platform_driver sta2x11_sctl_platform_driver = {
 	.driver = {
 		.name	= STA2X11_MFD_SCTL_NAME,
 	},
 	.probe		= sta2x11_sctl_probe,
 };

 static struct platform_driver sta2x11_platform_driver = {
 	.driver = {
 		.name	= STA2X11_MFD_APBREG_NAME,
 	},
 	.probe		= sta2x11_apbreg_probe,
 };

 static struct platform_driver sta2x11_apb_soc_regs_platform_driver = {
 	.driver = {
 		.name	= STA2X11_MFD_APB_SOC_REGS_NAME,
 	},
 	.probe		= sta2x11_apb_soc_regs_probe,
 };

 static struct platform_driver sta2x11_scr_platform_driver = {
 	.driver = {
 		.name = STA2X11_MFD_SCR_NAME,
 	},
 	.probe = sta2x11_scr_probe,
 };

 static struct platform_driver * const drivers[] = {
 	&sta2x11_platform_driver,
 	&sta2x11_sctl_platform_driver,
 	&sta2x11_apb_soc_regs_platform_driver,
 	&sta2x11_scr_platform_driver,
 };

 static int __init sta2x11_drivers_init(void)
 {
 	return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
 }

 /*
  * What follows are the PCI devices that host the above pdevs.
  * Each logic block is 4kB and they are all consecutive: we use this info.
  */

 /* Mfd 0 device */

 /* Mfd 0, Bar 0 */
 enum mfd0_bar0_cells {
 	STA2X11_GPIO_0 = 0,
 	STA2X11_GPIO_1,
 	STA2X11_GPIO_2,
 	STA2X11_GPIO_3,
 	STA2X11_SCTL,
 	STA2X11_SCR,
 	STA2X11_TIME,
 };
 /* Mfd 0 , Bar 1 */
 enum mfd0_bar1_cells {
 	STA2X11_APBREG = 0,
 };
 #define CELL_4K(_name, _cell) { \
 		.name = _name, \
 		.start = _cell * 4096, .end = _cell * 4096 + 4095, \
 		.flags = IORESOURCE_MEM, \
 		}

 static const struct resource gpio_resources[] = {
 	{
 		/* 4 consecutive cells, 1 driver */
 		.name = STA2X11_MFD_GPIO_NAME,
 		.start = 0,
 		.end = (4 * 4096) - 1,
 		.flags = IORESOURCE_MEM,
 	}
 };
 static const struct resource sctl_resources[] = {
 	CELL_4K(STA2X11_MFD_SCTL_NAME, STA2X11_SCTL),
 };
 static const struct resource scr_resources[] = {
 	CELL_4K(STA2X11_MFD_SCR_NAME, STA2X11_SCR),
 };
 static const struct resource time_resources[] = {
 	CELL_4K(STA2X11_MFD_TIME_NAME, STA2X11_TIME),
 };

 static const struct resource apbreg_resources[] = {
 	CELL_4K(STA2X11_MFD_APBREG_NAME, STA2X11_APBREG),
 };

 #define DEV(_name, _r) \
 	{ .name = _name, .num_resources = ARRAY_SIZE(_r), .resources = _r, }

 static struct mfd_cell sta2x11_mfd0_bar0[] = {
 	/* offset 0: we add pdata later */
 	DEV(STA2X11_MFD_GPIO_NAME, gpio_resources),
 	DEV(STA2X11_MFD_SCTL_NAME, sctl_resources),
 	DEV(STA2X11_MFD_SCR_NAME,  scr_resources),
 	DEV(STA2X11_MFD_TIME_NAME, time_resources),
 };

 static struct mfd_cell sta2x11_mfd0_bar1[] = {
 	DEV(STA2X11_MFD_APBREG_NAME, apbreg_resources),
 };

 /* Mfd 1 devices */

 /* Mfd 1, Bar 0 */
 enum mfd1_bar0_cells {
 	STA2X11_VIC = 0,
 };

 /* Mfd 1, Bar 1 */
 enum mfd1_bar1_cells {
 	STA2X11_APB_SOC_REGS = 0,
 };

 static const struct resource vic_resources[] = {
 	CELL_4K(STA2X11_MFD_VIC_NAME, STA2X11_VIC),
 };

 static const struct resource apb_soc_regs_resources[] = {
 	CELL_4K(STA2X11_MFD_APB_SOC_REGS_NAME, STA2X11_APB_SOC_REGS),
 };

 static struct mfd_cell sta2x11_mfd1_bar0[] = {
 	DEV(STA2X11_MFD_VIC_NAME, vic_resources),
 };

 static struct mfd_cell sta2x11_mfd1_bar1[] = {
 	DEV(STA2X11_MFD_APB_SOC_REGS_NAME, apb_soc_regs_resources),
 };


 static int sta2x11_mfd_suspend(struct pci_dev *pdev, pm_message_t state)
 {
 	pci_save_state(pdev);
 	pci_disable_device(pdev);
 	pci_set_power_state(pdev, pci_choose_state(pdev, state));

 	return 0;
 }

 static int sta2x11_mfd_resume(struct pci_dev *pdev)
 {
 	int err;

 	pci_set_power_state(pdev, PCI_D0);
 	err = pci_enable_device(pdev);
 	if (err)
 		return err;
 	pci_restore_state(pdev);

 	return 0;
 }

 struct sta2x11_mfd_bar_setup_data {
 	struct mfd_cell *cells;
 	int ncells;
 };

 struct sta2x11_mfd_setup_data {
 	struct sta2x11_mfd_bar_setup_data bars[2];
 };

 #define STA2X11_MFD0 0
 #define STA2X11_MFD1 1

 static struct sta2x11_mfd_setup_data mfd_setup_data[] = {
 	/* Mfd 0: gpio, sctl, scr, timers / apbregs */
 	[STA2X11_MFD0] = {
 		.bars = {
 			[0] = {
 				.cells = sta2x11_mfd0_bar0,
 				.ncells = ARRAY_SIZE(sta2x11_mfd0_bar0),
 			},
 			[1] = {
 				.cells = sta2x11_mfd0_bar1,
 				.ncells = ARRAY_SIZE(sta2x11_mfd0_bar1),
 			},
 		},
 	},
 	/* Mfd 1: vic / apb-soc-regs */
 	[STA2X11_MFD1] = {
 		.bars = {
 			[0] = {
 				.cells = sta2x11_mfd1_bar0,
 				.ncells = ARRAY_SIZE(sta2x11_mfd1_bar0),
 			},
 			[1] = {
 				.cells = sta2x11_mfd1_bar1,
 				.ncells = ARRAY_SIZE(sta2x11_mfd1_bar1),
 			},
 		},
 	},
 };

 static void sta2x11_mfd_setup(struct pci_dev *pdev,
 			      struct sta2x11_mfd_setup_data *sd)
 {
 	int i, j;
 	for (i = 0; i < ARRAY_SIZE(sd->bars); i++)
 		for (j = 0; j < sd->bars[i].ncells; j++) {
 			sd->bars[i].cells[j].pdata_size = sizeof(pdev);
 			sd->bars[i].cells[j].platform_data = &pdev;
 		}
 }

 static int sta2x11_mfd_probe(struct pci_dev *pdev,
 			     const struct pci_device_id *pci_id)
 {
 	int err, i;
 	struct sta2x11_mfd_setup_data *setup_data;

 	dev_info(&pdev->dev, "%s\n", __func__);

 	err = pci_enable_device(pdev);
 	if (err) {
 		dev_err(&pdev->dev, "Can't enable device.\n");
 		return err;
 	}

 	err = pci_enable_msi(pdev);
 	if (err)
 		dev_info(&pdev->dev, "Enable msi failed\n");

 	setup_data = pci_id->device == PCI_DEVICE_ID_STMICRO_GPIO ?
 		&mfd_setup_data[STA2X11_MFD0] :
 		&mfd_setup_data[STA2X11_MFD1];

 	/* platform data is the pci device for all of them */
 	sta2x11_mfd_setup(pdev, setup_data);

 	/* Record this pdev before mfd_add_devices: their probe looks for it */
 	if (!sta2x11_mfd_find(pdev))
 		sta2x11_mfd_add(pdev, GFP_ATOMIC);

 	/* Just 2 bars for all mfd's at present */
 	for (i = 0; i < 2; i++) {
 		err = mfd_add_devices(&pdev->dev, -1,
 				      setup_data->bars[i].cells,
 				      setup_data->bars[i].ncells,
 				      &pdev->resource[i],
 				      0, NULL);
 		if (err) {
 			dev_err(&pdev->dev,
 				"mfd_add_devices[%d] failed: %d\n", i, err);
 			goto err_disable;
 		}
 	}

 	return 0;

 err_disable:
 	mfd_remove_devices(&pdev->dev);
 	pci_disable_device(pdev);
 	pci_disable_msi(pdev);
 	return err;
 }

 static const struct pci_device_id sta2x11_mfd_tbl[] = {
 	{PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_GPIO)},
 	{PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_VIC)},
 	{0,},
 };

 static struct pci_driver sta2x11_mfd_driver = {
 	.name =		"sta2x11-mfd",
 	.id_table =	sta2x11_mfd_tbl,
 	.probe =	sta2x11_mfd_probe,
 	.suspend =	sta2x11_mfd_suspend,
 	.resume =	sta2x11_mfd_resume,
 };

 static int __init sta2x11_mfd_init(void)
 {
 	pr_info("%s\n", __func__);
 	return pci_register_driver(&sta2x11_mfd_driver);
 }

 /*
  * All of this must be ready before "normal" devices like MMCI appear.
  * But MFD (the pci device) can't be too early. The following choice
  * prepares platform drivers very early and probe the PCI device later,
  * but before other PCI devices.
  */
 subsys_initcall(sta2x11_drivers_init);
 rootfs_initcall(sta2x11_mfd_init);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* STA2x11 mfd for GPIO, SCTL and APBREG
	*
	* Copyright (c) 2009-2011 Wind River Systems, Inc.
	* Copyright (c) 2011 ST Microelectronics (Alessandro Rubini, Davide Ciminaghi)
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/export.h>
	#include <linux/spinlock.h>
	#include <linux/errno.h>
	#include <linux/device.h>
	#include <linux/slab.h>
	#include <linux/list.h>
	#include <linux/io.h>
	#include <linux/ioport.h>
	#include <linux/pci.h>
	#include <linux/seq_file.h>
	#include <linux/platform_device.h>
	#include <linux/mfd/core.h>
	#include <linux/mfd/sta2x11-mfd.h>
	#include <linux/regmap.h>

	#include <asm/sta2x11.h>

	static inline int __reg_within_range(unsigned int r,
	unsigned int start,
	unsigned int end)
	{
	return ((r >= start) && (r <= end));
	}

	/* This describes STA2X11 MFD chip for us, we may have several */
	struct sta2x11_mfd {
	struct sta2x11_instance *instance;
	struct regmap *regmap[sta2x11_n_mfd_plat_devs];
	spinlock_t lock[sta2x11_n_mfd_plat_devs];
	struct list_head list;
	void __iomem *regs[sta2x11_n_mfd_plat_devs];
	};

	static LIST_HEAD(sta2x11_mfd_list);

	/* Three functions to act on the list */
	static struct sta2x11_mfd sta2x11_mfd_find(struct pci_dev pdev)
	{
	struct sta2x11_instance *instance;
	struct sta2x11_mfd *mfd;

	if (!pdev && !list_empty(&sta2x11_mfd_list)) {
	pr_warn("%s: Unspecified device, using first instance\n",
	__func__);
	return list_entry(sta2x11_mfd_list.next,
	struct sta2x11_mfd, list);
	}

	instance = sta2x11_get_instance(pdev);
	if (!instance)
	return NULL;
	list_for_each_entry(mfd, &sta2x11_mfd_list, list) {
	if (mfd->instance == instance)
	return mfd;
	}
	return NULL;
	}

	static int sta2x11_mfd_add(struct pci_dev *pdev, gfp_t flags)
	{
	int i;
	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
	struct sta2x11_instance *instance;

	if (mfd)
	return -EBUSY;
	instance = sta2x11_get_instance(pdev);
	if (!instance)
	return -EINVAL;
	mfd = kzalloc(sizeof(*mfd), flags);
	if (!mfd)
	return -ENOMEM;
	INIT_LIST_HEAD(&mfd->list);
	for (i = 0; i < ARRAY_SIZE(mfd->lock); i++)
	spin_lock_init(&mfd->lock[i]);
	mfd->instance = instance;
	list_add(&mfd->list, &sta2x11_mfd_list);
	return 0;
	}

	/* This function is exported and is not expected to fail */
	u32 __sta2x11_mfd_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val,
	enum sta2x11_mfd_plat_dev index)
	{
	struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
	u32 r;
	unsigned long flags;
	void __iomem *regs;

	if (!mfd) {
	dev_warn(&pdev->dev, ": can't access sctl regs\n");
	return 0;
	}

	regs = mfd->regs[index];
	if (!regs) {
	dev_warn(&pdev->dev, ": system ctl not initialized\n");
	return 0;
	}
	spin_lock_irqsave(&mfd->lock[index], flags);
	r = readl(regs + reg);
	r &= ~mask;
	r \|= val;
	if (mask)
	writel(r, regs + reg);
	spin_unlock_irqrestore(&mfd->lock[index], flags);
	return r;
	}
	EXPORT_SYMBOL(__sta2x11_mfd_mask);

	int sta2x11_mfd_get_regs_data(struct platform_device *dev,
	enum sta2x11_mfd_plat_dev index,
	void __iomem **regs,
	spinlock_t **lock)
	{
	struct pci_dev pdev = (struct pci_dev **)dev_get_platdata(&dev->dev);
	struct sta2x11_mfd *mfd;

	if (!pdev)
	return -ENODEV;
	mfd = sta2x11_mfd_find(pdev);
	if (!mfd)
	return -ENODEV;
	if (index >= sta2x11_n_mfd_plat_devs)
	return -ENODEV;
	*regs = mfd->regs[index];
	*lock = &mfd->lock[index];
	pr_debug("%s %d regs = %p\n", __func__, __LINE__, regs);
	return *regs ? 0 : -ENODEV;
	}
	EXPORT_SYMBOL(sta2x11_mfd_get_regs_data);

	/*
	* Special sta2x11-mfd regmap lock/unlock functions
	*/

	static void sta2x11_regmap_lock(void *__lock)
	{
	spinlock_t *lock = __lock;
	spin_lock(lock);
	}

	static void sta2x11_regmap_unlock(void *__lock)
	{
	spinlock_t *lock = __lock;
	spin_unlock(lock);
	}

	/* OTP (one time programmable registers do not require locking */
	static void sta2x11_regmap_nolock(void *__lock)
	{
	}

	static const char *sta2x11_mfd_names[sta2x11_n_mfd_plat_devs] = {
	[sta2x11_sctl] = STA2X11_MFD_SCTL_NAME,
	[sta2x11_apbreg] = STA2X11_MFD_APBREG_NAME,
	[sta2x11_apb_soc_regs] = STA2X11_MFD_APB_SOC_REGS_NAME,
	[sta2x11_scr] = STA2X11_MFD_SCR_NAME,
	};

	static bool sta2x11_sctl_writeable_reg(struct device *dev, unsigned int reg)
	{
	return !__reg_within_range(reg, SCTL_SCPCIECSBRST, SCTL_SCRSTSTA);
	}

	static struct regmap_config sta2x11_sctl_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.lock = sta2x11_regmap_lock,
	.unlock = sta2x11_regmap_unlock,
	.max_register = SCTL_SCRSTSTA,
	.writeable_reg = sta2x11_sctl_writeable_reg,
	};

	static bool sta2x11_scr_readable_reg(struct device *dev, unsigned int reg)
	{
	return (reg == STA2X11_SECR_CR) \|\|
	__reg_within_range(reg, STA2X11_SECR_FVR0, STA2X11_SECR_FVR1);
	}

	static bool sta2x11_scr_writeable_reg(struct device *dev, unsigned int reg)
	{
	return false;
	}

	static struct regmap_config sta2x11_scr_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.lock = sta2x11_regmap_nolock,
	.unlock = sta2x11_regmap_nolock,
	.max_register = STA2X11_SECR_FVR1,
	.readable_reg = sta2x11_scr_readable_reg,
	.writeable_reg = sta2x11_scr_writeable_reg,
	};

	static bool sta2x11_apbreg_readable_reg(struct device *dev, unsigned int reg)
	{
	/* Two blocks (CAN and MLB, SARAC) 0x100 bytes apart */
	if (reg >= APBREG_BSR_SARAC)
	reg -= APBREG_BSR_SARAC;
	switch (reg) {
	case APBREG_BSR:
	case APBREG_PAER:
	case APBREG_PWAC:
	case APBREG_PRAC:
	case APBREG_PCG:
	case APBREG_PUR:
	case APBREG_EMU_PCG:
	return true;
	default:
	return false;
	}
	}

	static bool sta2x11_apbreg_writeable_reg(struct device *dev, unsigned int reg)
	{
	if (reg >= APBREG_BSR_SARAC)
	reg -= APBREG_BSR_SARAC;
	if (!sta2x11_apbreg_readable_reg(dev, reg))
	return false;
	return reg != APBREG_PAER;
	}

	static struct regmap_config sta2x11_apbreg_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.lock = sta2x11_regmap_lock,
	.unlock = sta2x11_regmap_unlock,
	.max_register = APBREG_EMU_PCG_SARAC,
	.readable_reg = sta2x11_apbreg_readable_reg,
	.writeable_reg = sta2x11_apbreg_writeable_reg,
	};

	static bool sta2x11_apb_soc_regs_readable_reg(struct device *dev,
	unsigned int reg)
	{
	return reg <= PCIE_SoC_INT_ROUTER_STATUS3_REG \|\|
	__reg_within_range(reg, DMA_IP_CTRL_REG, SPARE3_RESERVED) \|\|
	__reg_within_range(reg, MASTER_LOCK_REG,
	SYSTEM_CONFIG_STATUS_REG) \|\|
	reg == MSP_CLK_CTRL_REG \|\|
	__reg_within_range(reg, COMPENSATION_REG1, TEST_CTL_REG);
	}

	static bool sta2x11_apb_soc_regs_writeable_reg(struct device *dev,
	unsigned int reg)
	{
	if (!sta2x11_apb_soc_regs_readable_reg(dev, reg))
	return false;
	switch (reg) {
	case PCIE_COMMON_CLOCK_CONFIG_0_4_0:
	case SYSTEM_CONFIG_STATUS_REG:
	case COMPENSATION_REG1:
	case PCIE_SoC_INT_ROUTER_STATUS0_REG...PCIE_SoC_INT_ROUTER_STATUS3_REG:
	case PCIE_PM_STATUS_0_PORT_0_4...PCIE_PM_STATUS_7_0_EP4:
	return false;
	default:
	return true;
	}
	}

	static struct regmap_config sta2x11_apb_soc_regs_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.lock = sta2x11_regmap_lock,
	.unlock = sta2x11_regmap_unlock,
	.max_register = TEST_CTL_REG,
	.readable_reg = sta2x11_apb_soc_regs_readable_reg,
	.writeable_reg = sta2x11_apb_soc_regs_writeable_reg,
	};

	static struct regmap_config *
	sta2x11_mfd_regmap_configs[sta2x11_n_mfd_plat_devs] = {
	[sta2x11_sctl] = &sta2x11_sctl_regmap_config,
	[sta2x11_apbreg] = &sta2x11_apbreg_regmap_config,
	[sta2x11_apb_soc_regs] = &sta2x11_apb_soc_regs_regmap_config,
	[sta2x11_scr] = &sta2x11_scr_regmap_config,
	};

	/* Probe for the four platform devices */

	static int sta2x11_mfd_platform_probe(struct platform_device *dev,
	enum sta2x11_mfd_plat_dev index)
	{
	struct pci_dev **pdev;
	struct sta2x11_mfd *mfd;
	struct resource *res;
	const char *name = sta2x11_mfd_names[index];
	struct regmap_config *regmap_config = sta2x11_mfd_regmap_configs[index];

	pdev = dev_get_platdata(&dev->dev);
	mfd = sta2x11_mfd_find(*pdev);
	if (!mfd)
	return -ENODEV;
	if (!regmap_config)
	return -ENODEV;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
	return -ENOMEM;

	if (!request_mem_region(res->start, resource_size(res), name))
	return -EBUSY;

	mfd->regs[index] = ioremap(res->start, resource_size(res));
	if (!mfd->regs[index]) {
	release_mem_region(res->start, resource_size(res));
	return -ENOMEM;
	}
	regmap_config->lock_arg = &mfd->lock;
	/*
	No caching, registers could be reached both via regmap and via
	void __iomem *
	*/
	regmap_config->cache_type = REGCACHE_NONE;
	mfd->regmap[index] = devm_regmap_init_mmio(&dev->dev, mfd->regs[index],
	regmap_config);
	WARN_ON(IS_ERR(mfd->regmap[index]));

	return 0;
	}

	static int sta2x11_sctl_probe(struct platform_device *dev)
	{
	return sta2x11_mfd_platform_probe(dev, sta2x11_sctl);
	}

	static int sta2x11_apbreg_probe(struct platform_device *dev)
	{
	return sta2x11_mfd_platform_probe(dev, sta2x11_apbreg);
	}

	static int sta2x11_apb_soc_regs_probe(struct platform_device *dev)
	{
	return sta2x11_mfd_platform_probe(dev, sta2x11_apb_soc_regs);
	}

	static int sta2x11_scr_probe(struct platform_device *dev)
	{
	return sta2x11_mfd_platform_probe(dev, sta2x11_scr);
	}

	/* The three platform drivers */
	static struct platform_driver sta2x11_sctl_platform_driver = {
	.driver = {
	.name = STA2X11_MFD_SCTL_NAME,
	},
	.probe = sta2x11_sctl_probe,
	};

	static struct platform_driver sta2x11_platform_driver = {
	.driver = {
	.name = STA2X11_MFD_APBREG_NAME,
	},
	.probe = sta2x11_apbreg_probe,
	};

	static struct platform_driver sta2x11_apb_soc_regs_platform_driver = {
	.driver = {
	.name = STA2X11_MFD_APB_SOC_REGS_NAME,
	},
	.probe = sta2x11_apb_soc_regs_probe,
	};

	static struct platform_driver sta2x11_scr_platform_driver = {
	.driver = {
	.name = STA2X11_MFD_SCR_NAME,
	},
	.probe = sta2x11_scr_probe,
	};

	static struct platform_driver * const drivers[] = {
	&sta2x11_platform_driver,
	&sta2x11_sctl_platform_driver,
	&sta2x11_apb_soc_regs_platform_driver,
	&sta2x11_scr_platform_driver,
	};

	static int __init sta2x11_drivers_init(void)
	{
	return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
	}

	/*
	* What follows are the PCI devices that host the above pdevs.
	* Each logic block is 4kB and they are all consecutive: we use this info.
	*/

	/* Mfd 0 device */

	/* Mfd 0, Bar 0 */
	enum mfd0_bar0_cells {
	STA2X11_GPIO_0 = 0,
	STA2X11_GPIO_1,
	STA2X11_GPIO_2,
	STA2X11_GPIO_3,
	STA2X11_SCTL,
	STA2X11_SCR,
	STA2X11_TIME,
	};
	/* Mfd 0 , Bar 1 */
	enum mfd0_bar1_cells {
	STA2X11_APBREG = 0,
	};
	#define CELL_4K(_name, _cell) { \
	.name = _name, \
	.start = _cell * 4096, .end = _cell * 4096 + 4095, \
	.flags = IORESOURCE_MEM, \
	}

	static const struct resource gpio_resources[] = {
	{
	/* 4 consecutive cells, 1 driver */
	.name = STA2X11_MFD_GPIO_NAME,
	.start = 0,
	.end = (4 * 4096) - 1,
	.flags = IORESOURCE_MEM,
	}
	};
	static const struct resource sctl_resources[] = {
	CELL_4K(STA2X11_MFD_SCTL_NAME, STA2X11_SCTL),
	};
	static const struct resource scr_resources[] = {
	CELL_4K(STA2X11_MFD_SCR_NAME, STA2X11_SCR),
	};
	static const struct resource time_resources[] = {
	CELL_4K(STA2X11_MFD_TIME_NAME, STA2X11_TIME),
	};

	static const struct resource apbreg_resources[] = {
	CELL_4K(STA2X11_MFD_APBREG_NAME, STA2X11_APBREG),
	};

	#define DEV(_name, _r) \
	{ .name = _name, .num_resources = ARRAY_SIZE(_r), .resources = _r, }

	static struct mfd_cell sta2x11_mfd0_bar0[] = {
	/* offset 0: we add pdata later */
	DEV(STA2X11_MFD_GPIO_NAME, gpio_resources),
	DEV(STA2X11_MFD_SCTL_NAME, sctl_resources),
	DEV(STA2X11_MFD_SCR_NAME, scr_resources),
	DEV(STA2X11_MFD_TIME_NAME, time_resources),
	};

	static struct mfd_cell sta2x11_mfd0_bar1[] = {
	DEV(STA2X11_MFD_APBREG_NAME, apbreg_resources),
	};

	/* Mfd 1 devices */

	/* Mfd 1, Bar 0 */
	enum mfd1_bar0_cells {
	STA2X11_VIC = 0,
	};

	/* Mfd 1, Bar 1 */
	enum mfd1_bar1_cells {
	STA2X11_APB_SOC_REGS = 0,
	};

	static const struct resource vic_resources[] = {
	CELL_4K(STA2X11_MFD_VIC_NAME, STA2X11_VIC),
	};

	static const struct resource apb_soc_regs_resources[] = {
	CELL_4K(STA2X11_MFD_APB_SOC_REGS_NAME, STA2X11_APB_SOC_REGS),
	};

	static struct mfd_cell sta2x11_mfd1_bar0[] = {
	DEV(STA2X11_MFD_VIC_NAME, vic_resources),
	};

	static struct mfd_cell sta2x11_mfd1_bar1[] = {
	DEV(STA2X11_MFD_APB_SOC_REGS_NAME, apb_soc_regs_resources),
	};


	static int sta2x11_mfd_suspend(struct pci_dev *pdev, pm_message_t state)
	{
	pci_save_state(pdev);
	pci_disable_device(pdev);
	pci_set_power_state(pdev, pci_choose_state(pdev, state));

	return 0;
	}

	static int sta2x11_mfd_resume(struct pci_dev *pdev)
	{
	int err;

	pci_set_power_state(pdev, PCI_D0);
	err = pci_enable_device(pdev);
	if (err)
	return err;
	pci_restore_state(pdev);

	return 0;
	}

	struct sta2x11_mfd_bar_setup_data {
	struct mfd_cell *cells;
	int ncells;
	};

	struct sta2x11_mfd_setup_data {
	struct sta2x11_mfd_bar_setup_data bars[2];
	};

	#define STA2X11_MFD0 0
	#define STA2X11_MFD1 1

	static struct sta2x11_mfd_setup_data mfd_setup_data[] = {
	/* Mfd 0: gpio, sctl, scr, timers / apbregs */
	[STA2X11_MFD0] = {
	.bars = {
	[0] = {
	.cells = sta2x11_mfd0_bar0,
	.ncells = ARRAY_SIZE(sta2x11_mfd0_bar0),
	},
	[1] = {
	.cells = sta2x11_mfd0_bar1,
	.ncells = ARRAY_SIZE(sta2x11_mfd0_bar1),
	},
	},
	},
	/* Mfd 1: vic / apb-soc-regs */
	[STA2X11_MFD1] = {
	.bars = {
	[0] = {
	.cells = sta2x11_mfd1_bar0,
	.ncells = ARRAY_SIZE(sta2x11_mfd1_bar0),
	},
	[1] = {
	.cells = sta2x11_mfd1_bar1,
	.ncells = ARRAY_SIZE(sta2x11_mfd1_bar1),
	},
	},
	},
	};

	static void sta2x11_mfd_setup(struct pci_dev *pdev,
	struct sta2x11_mfd_setup_data *sd)
	{
	int i, j;
	for (i = 0; i < ARRAY_SIZE(sd->bars); i++)
	for (j = 0; j < sd->bars[i].ncells; j++) {
	sd->bars[i].cells[j].pdata_size = sizeof(pdev);
	sd->bars[i].cells[j].platform_data = &pdev;
	}
	}

	static int sta2x11_mfd_probe(struct pci_dev *pdev,
	const struct pci_device_id *pci_id)
	{
	int err, i;
	struct sta2x11_mfd_setup_data *setup_data;

	dev_info(&pdev->dev, "%s\n", __func__);

	err = pci_enable_device(pdev);
	if (err) {
	dev_err(&pdev->dev, "Can't enable device.\n");
	return err;
	}

	err = pci_enable_msi(pdev);
	if (err)
	dev_info(&pdev->dev, "Enable msi failed\n");

	setup_data = pci_id->device == PCI_DEVICE_ID_STMICRO_GPIO ?
	&mfd_setup_data[STA2X11_MFD0] :
	&mfd_setup_data[STA2X11_MFD1];

	/* platform data is the pci device for all of them */
	sta2x11_mfd_setup(pdev, setup_data);

	/* Record this pdev before mfd_add_devices: their probe looks for it */
	if (!sta2x11_mfd_find(pdev))
	sta2x11_mfd_add(pdev, GFP_ATOMIC);

	/* Just 2 bars for all mfd's at present */
	for (i = 0; i < 2; i++) {
	err = mfd_add_devices(&pdev->dev, -1,
	setup_data->bars[i].cells,
	setup_data->bars[i].ncells,
	&pdev->resource[i],
	0, NULL);
	if (err) {
	dev_err(&pdev->dev,
	"mfd_add_devices[%d] failed: %d\n", i, err);
	goto err_disable;
	}
	}

	return 0;

	err_disable:
	mfd_remove_devices(&pdev->dev);
	pci_disable_device(pdev);
	pci_disable_msi(pdev);
	return err;
	}

	static const struct pci_device_id sta2x11_mfd_tbl[] = {
	{PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_GPIO)},
	{PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_VIC)},
	{0,},
	};

	static struct pci_driver sta2x11_mfd_driver = {
	.name = "sta2x11-mfd",
	.id_table = sta2x11_mfd_tbl,
	.probe = sta2x11_mfd_probe,
	.suspend = sta2x11_mfd_suspend,
	.resume = sta2x11_mfd_resume,
	};

	static int __init sta2x11_mfd_init(void)
	{
	pr_info("%s\n", __func__);
	return pci_register_driver(&sta2x11_mfd_driver);
	}

	/*
	* All of this must be ready before "normal" devices like MMCI appear.
	* But MFD (the pci device) can't be too early. The following choice
	* prepares platform drivers very early and probe the PCI device later,
	* but before other PCI devices.
	*/
	subsys_initcall(sta2x11_drivers_init);
	rootfs_initcall(sta2x11_mfd_init);