Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1462 insertions, 0 deletions

diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
new file mode 100644
index 0000000000..139ad7ad1d
--- /dev/null
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -0,0 +1,1462 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/dmi.h>
+#include <linux/efi.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <media/v4l2-subdev.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include "../../include/linux/atomisp_platform.h"
+#include "../../include/linux/atomisp_gmin_platform.h"
+
+#define MAX_SUBDEVS 8
+
+enum clock_rate {
+	VLV2_CLK_XTAL_25_0MHz = 0,
+	VLV2_CLK_PLL_19P2MHZ = 1
+};
+
+#define CLK_RATE_19_2MHZ	19200000
+#define CLK_RATE_25_0MHZ	25000000
+
+/* Valid clock number range from 0 to 5 */
+#define MAX_CLK_COUNT                   5
+
+/* X-Powers AXP288 register set */
+#define ALDO1_SEL_REG	0x28
+#define ALDO1_CTRL3_REG	0x13
+#define ALDO1_2P8V	0x16
+#define ALDO1_CTRL3_SHIFT 0x05
+
+#define ELDO_CTRL_REG   0x12
+
+#define ELDO1_SEL_REG	0x19
+#define ELDO1_1P6V	0x12
+#define ELDO1_CTRL_SHIFT 0x00
+
+#define ELDO2_SEL_REG	0x1a
+#define ELDO2_1P8V	0x16
+#define ELDO2_CTRL_SHIFT 0x01
+
+/* TI SND9039 PMIC register set */
+#define LDO9_REG	0x49
+#define LDO10_REG	0x4a
+#define LDO11_REG	0x4b
+
+#define LDO_2P8V_ON	0x2f /* 0x2e selects 2.85V ...      */
+#define LDO_2P8V_OFF	0x2e /* ... bottom bit is "enabled" */
+
+#define LDO_1P8V_ON	0x59 /* 0x58 selects 1.80V ...      */
+#define LDO_1P8V_OFF	0x58 /* ... bottom bit is "enabled" */
+
+/* CRYSTAL COVE PMIC register set */
+#define CRYSTAL_BYT_1P8V_REG	0x5d
+#define CRYSTAL_BYT_2P8V_REG	0x66
+
+#define CRYSTAL_CHT_1P8V_REG	0x57
+#define CRYSTAL_CHT_2P8V_REG	0x5d
+
+#define CRYSTAL_ON		0x63
+#define CRYSTAL_OFF		0x62
+
+struct gmin_subdev {
+	struct v4l2_subdev *subdev;
+	enum clock_rate clock_src;
+	struct clk *pmc_clk;
+	struct gpio_desc *gpio0;
+	struct gpio_desc *gpio1;
+	struct regulator *v1p8_reg;
+	struct regulator *v2p8_reg;
+	struct regulator *v1p2_reg;
+	struct regulator *v2p8_vcm_reg;
+	enum atomisp_camera_port csi_port;
+	unsigned int csi_lanes;
+	enum atomisp_input_format csi_fmt;
+	enum atomisp_bayer_order csi_bayer;
+
+	bool clock_on;
+	bool v1p8_on;
+	bool v2p8_on;
+	bool v1p2_on;
+	bool v2p8_vcm_on;
+
+	int v1p8_gpio;
+	int v2p8_gpio;
+
+	u8 pwm_i2c_addr;
+
+	/* For PMIC AXP */
+	int eldo1_sel_reg, eldo1_1p6v, eldo1_ctrl_shift;
+	int eldo2_sel_reg, eldo2_1p8v, eldo2_ctrl_shift;
+};
+
+static struct gmin_subdev gmin_subdevs[MAX_SUBDEVS];
+
+/* ACPI HIDs for the PMICs that could be used by this driver */
+#define PMIC_ACPI_AXP		"INT33F4"	/* XPower AXP288 PMIC */
+#define PMIC_ACPI_TI		"INT33F5"	/* Dollar Cove TI PMIC */
+#define PMIC_ACPI_CRYSTALCOVE	"INT33FD"	/* Crystal Cove PMIC */
+
+#define PMIC_PLATFORM_TI	"intel_soc_pmic_chtdc_ti"
+
+static enum {
+	PMIC_UNSET = 0,
+	PMIC_REGULATOR,
+	PMIC_AXP,
+	PMIC_TI,
+	PMIC_CRYSTALCOVE
+} pmic_id;
+
+static const char *pmic_name[] = {
+	[PMIC_UNSET]		= "ACPI device PM",
+	[PMIC_REGULATOR]	= "regulator driver",
+	[PMIC_AXP]		= "XPower AXP288 PMIC",
+	[PMIC_TI]		= "Dollar Cove TI PMIC",
+	[PMIC_CRYSTALCOVE]	= "Crystal Cove PMIC",
+};
+
+static DEFINE_MUTEX(gmin_regulator_mutex);
+static int gmin_v1p8_enable_count;
+static int gmin_v2p8_enable_count;
+
+/* The atomisp uses type==0 for the end-of-list marker, so leave space. */
+static struct intel_v4l2_subdev_table pdata_subdevs[MAX_SUBDEVS + 1];
+
+static const struct atomisp_platform_data pdata = {
+	.subdevs = pdata_subdevs,
+};
+
+static LIST_HEAD(vcm_devices);
+static DEFINE_MUTEX(vcm_lock);
+
+static struct gmin_subdev *find_gmin_subdev(struct v4l2_subdev *subdev);
+
+const struct atomisp_platform_data *atomisp_get_platform_data(void)
+{
+	return &pdata;
+}
+EXPORT_SYMBOL_GPL(atomisp_get_platform_data);
+
+int atomisp_register_i2c_module(struct v4l2_subdev *subdev,
+				struct camera_sensor_platform_data *plat_data,
+				enum intel_v4l2_subdev_type type)
+{
+	int i;
+	struct gmin_subdev *gs;
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+
+	dev_info(&client->dev, "register atomisp i2c module type %d\n", type);
+
+	/* The windows driver model (and thus most BIOSes by default)
+	 * uses ACPI runtime power management for camera devices, but
+	 * we don't.  Disable it, or else the rails will be needlessly
+	 * tickled during suspend/resume.  This has caused power and
+	 * performance issues on multiple devices.
+	 */
+
+	/*
+	 * Turn off the device before disabling ACPI power resources
+	 * (the sensor driver has already probed it at this point).
+	 * This avoids leaking the reference count of the (possibly shared)
+	 * ACPI power resources which were enabled/referenced before probe().
+	 */
+	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
+	adev->power.flags.power_resources = 0;
+
+	for (i = 0; i < MAX_SUBDEVS; i++)
+		if (!pdata.subdevs[i].type)
+			break;
+
+	if (pdata.subdevs[i].type)
+		return -ENOMEM;
+
+	/* Note subtlety of initialization order: at the point where
+	 * this registration API gets called, the platform data
+	 * callbacks have probably already been invoked, so the
+	 * gmin_subdev struct is already initialized for us.
+	 */
+	gs = find_gmin_subdev(subdev);
+	if (!gs)
+		return -ENODEV;
+
+	pdata.subdevs[i].type = type;
+	pdata.subdevs[i].port = gs->csi_port;
+	pdata.subdevs[i].lanes = gs->csi_lanes;
+	pdata.subdevs[i].subdev = subdev;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(atomisp_register_i2c_module);
+
+int atomisp_gmin_remove_subdev(struct v4l2_subdev *sd)
+{
+	int i, j;
+
+	if (!sd)
+		return 0;
+
+	for (i = 0; i < MAX_SUBDEVS; i++) {
+		if (pdata.subdevs[i].subdev == sd) {
+			for (j = i + 1; j <= MAX_SUBDEVS; j++)
+				pdata.subdevs[j - 1] = pdata.subdevs[j];
+		}
+		if (gmin_subdevs[i].subdev == sd) {
+			if (gmin_subdevs[i].gpio0)
+				gpiod_put(gmin_subdevs[i].gpio0);
+			gmin_subdevs[i].gpio0 = NULL;
+			if (gmin_subdevs[i].gpio1)
+				gpiod_put(gmin_subdevs[i].gpio1);
+			gmin_subdevs[i].gpio1 = NULL;
+			if (pmic_id == PMIC_REGULATOR) {
+				regulator_put(gmin_subdevs[i].v1p8_reg);
+				regulator_put(gmin_subdevs[i].v2p8_reg);
+				regulator_put(gmin_subdevs[i].v1p2_reg);
+				regulator_put(gmin_subdevs[i].v2p8_vcm_reg);
+			}
+			gmin_subdevs[i].subdev = NULL;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(atomisp_gmin_remove_subdev);
+
+struct gmin_cfg_var {
+	const char *name, *val;
+};
+
+static struct gmin_cfg_var ffrd8_vars[] = {
+	{ "INTCF1B:00_ImxId",    "0x134" },
+	{ "INTCF1B:00_CsiPort",  "1" },
+	{ "INTCF1B:00_CsiLanes", "4" },
+	{ "INTCF1B:00_CamClk", "0" },
+	{},
+};
+
+/* Cribbed from MCG defaults in the mt9m114 driver, not actually verified
+ * vs. T100 hardware
+ */
+static struct gmin_cfg_var t100_vars[] = {
+	{ "INT33F0:00_CsiPort",  "0" },
+	{ "INT33F0:00_CsiLanes", "1" },
+	{ "INT33F0:00_CamClk",   "1" },
+	{},
+};
+
+static struct gmin_cfg_var mrd7_vars[] = {
+	{"INT33F8:00_CamType", "1"},
+	{"INT33F8:00_CsiPort", "1"},
+	{"INT33F8:00_CsiLanes", "2"},
+	{"INT33F8:00_CsiFmt", "13"},
+	{"INT33F8:00_CsiBayer", "0"},
+	{"INT33F8:00_CamClk", "0"},
+
+	{"INT33F9:00_CamType", "1"},
+	{"INT33F9:00_CsiPort", "0"},
+	{"INT33F9:00_CsiLanes", "1"},
+	{"INT33F9:00_CsiFmt", "13"},
+	{"INT33F9:00_CsiBayer", "0"},
+	{"INT33F9:00_CamClk", "1"},
+	{},
+};
+
+static struct gmin_cfg_var ecs7_vars[] = {
+	{"INT33BE:00_CsiPort", "1"},
+	{"INT33BE:00_CsiLanes", "2"},
+	{"INT33BE:00_CsiFmt", "13"},
+	{"INT33BE:00_CsiBayer", "2"},
+	{"INT33BE:00_CamClk", "0"},
+
+	{"INT33F0:00_CsiPort", "0"},
+	{"INT33F0:00_CsiLanes", "1"},
+	{"INT33F0:00_CsiFmt", "13"},
+	{"INT33F0:00_CsiBayer", "0"},
+	{"INT33F0:00_CamClk", "1"},
+	{"gmin_V2P8GPIO", "402"},
+	{},
+};
+
+static struct gmin_cfg_var i8880_vars[] = {
+	{"XXOV2680:00_CsiPort", "1"},
+	{"XXOV2680:00_CsiLanes", "1"},
+	{"XXOV2680:00_CamClk", "0"},
+
+	{"XXGC0310:00_CsiPort", "0"},
+	{"XXGC0310:00_CsiLanes", "1"},
+	{"XXGC0310:00_CamClk", "1"},
+	{},
+};
+
+/*
+ * Surface 3 does not describe CsiPort/CsiLanes in both DSDT and EFI.
+ */
+static struct gmin_cfg_var surface3_vars[] = {
+	{"APTA0330:00_CsiPort", "0"},
+	{"APTA0330:00_CsiLanes", "2"},
+
+	{"OVTI8835:00_CsiPort", "1"},
+	{"OVTI8835:00_CsiLanes", "4"},
+	{},
+};
+
+static struct gmin_cfg_var lenovo_ideapad_miix_310_vars[] = {
+	/* _DSM contains the wrong CsiPort! */
+	{ "OVTI2680:01_CsiPort", "0" },
+	{}
+};
+
+static const struct dmi_system_id gmin_vars[] = {
+	/*
+	 * These DMI IDs were present when the atomisp driver was merged into
+	 * drivers/staging and it is unclear if they are really necessary.
+	 */
+	{
+		.ident = "BYT-T FFD8",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "BYT-T FFD8"),
+		},
+		.driver_data = ffrd8_vars,
+	},
+	{
+		.ident = "T100TA",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "T100TA"),
+		},
+		.driver_data = t100_vars,
+	},
+	{
+		.ident = "MRD7",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "TABLET"),
+			DMI_MATCH(DMI_BOARD_VERSION, "MRD 7"),
+		},
+		.driver_data = mrd7_vars,
+	},
+	{
+		.ident = "ST70408",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "ST70408"),
+		},
+		.driver_data = ecs7_vars,
+	},
+	{
+		.ident = "VTA0803",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "VTA0803"),
+		},
+		.driver_data = i8880_vars,
+	},
+	/* Later added DMI ids, these are confirmed to really be necessary! */
+	{
+		.ident = "Surface 3",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "Surface 3"),
+		},
+		.driver_data = surface3_vars,
+	},
+	{
+		.ident = "Lenovo Ideapad Miix 310",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "MIIX 310-10"),
+		},
+		.driver_data = lenovo_ideapad_miix_310_vars,
+	},
+	{}
+};
+
+#define GMIN_CFG_VAR_EFI_GUID EFI_GUID(0xecb54cd9, 0xe5ae, 0x4fdc, \
+				       0xa9, 0x71, 0xe8, 0x77,	   \
+				       0x75, 0x60, 0x68, 0xf7)
+
+static const guid_t atomisp_dsm_guid = GUID_INIT(0xdc2f6c4f, 0x045b, 0x4f1d,
+						 0x97, 0xb9, 0x88, 0x2a,
+						 0x68, 0x60, 0xa4, 0xbe);
+
+#define CFG_VAR_NAME_MAX 64
+
+#define GMIN_PMC_CLK_NAME 14 /* "pmc_plt_clk_[0..5]" */
+static char gmin_pmc_clk_name[GMIN_PMC_CLK_NAME];
+
+static struct i2c_client *gmin_i2c_dev_exists(struct device *dev, char *name,
+					      struct i2c_client **client)
+{
+	struct acpi_device *adev;
+	struct device *d;
+
+	adev = acpi_dev_get_first_match_dev(name, NULL, -1);
+	if (!adev)
+		return NULL;
+
+	d = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
+	acpi_dev_put(adev);
+	if (!d)
+		return NULL;
+
+	*client = i2c_verify_client(d);
+	put_device(d);
+
+	dev_dbg(dev, "found '%s' at address 0x%02x, adapter %d\n",
+		(*client)->name, (*client)->addr, (*client)->adapter->nr);
+	return *client;
+}
+
+static int gmin_i2c_write(struct device *dev, u16 i2c_addr, u8 reg,
+			  u32 value, u32 mask)
+{
+	int ret;
+
+	/*
+	 * FIXME: Right now, the intel_pmic driver just write values
+	 * directly at the regmap, instead of properly implementing
+	 * i2c_transfer() mechanism. Let's use the same interface here,
+	 * as otherwise we may face issues.
+	 */
+
+	dev_dbg(dev,
+		"I2C write, addr: 0x%02x, reg: 0x%02x, value: 0x%02x, mask: 0x%02x\n",
+		i2c_addr, reg, value, mask);
+
+	ret = intel_soc_pmic_exec_mipi_pmic_seq_element(i2c_addr, reg, value, mask);
+	if (ret == -EOPNOTSUPP)
+		dev_err(dev,
+			"ACPI didn't mapped the OpRegion needed to access I2C address 0x%02x.\n"
+			"Need to compile the kernel using CONFIG_*_PMIC_OPREGION settings\n",
+			i2c_addr);
+
+	return ret;
+}
+
+static int atomisp_get_acpi_power(struct device *dev)
+{
+	char name[5];
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_buffer b_name = { sizeof(name), name };
+	union acpi_object *package, *element;
+	acpi_handle handle = ACPI_HANDLE(dev);
+	acpi_handle rhandle;
+	acpi_status status;
+	int clock_num = -1;
+	int i;
+
+	status = acpi_evaluate_object(handle, "_PR0", NULL, &buffer);
+	if (!ACPI_SUCCESS(status))
+		return -1;
+
+	package = buffer.pointer;
+
+	if (!buffer.length || !package
+	    || package->type != ACPI_TYPE_PACKAGE
+	    || !package->package.count)
+		goto fail;
+
+	for (i = 0; i < package->package.count; i++) {
+		element = &package->package.elements[i];
+
+		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
+			continue;
+
+		rhandle = element->reference.handle;
+		if (!rhandle)
+			goto fail;
+
+		acpi_get_name(rhandle, ACPI_SINGLE_NAME, &b_name);
+
+		dev_dbg(dev, "Found PM resource '%s'\n", name);
+		if (strlen(name) == 4 && !strncmp(name, "CLK", 3)) {
+			if (name[3] >= '0' && name[3] <= '4')
+				clock_num = name[3] - '0';
+#if 0
+			/*
+			 * We could abort here, but let's parse all resources,
+			 * as this is helpful for debugging purposes
+			 */
+			if (clock_num >= 0)
+				break;
+#endif
+		}
+	}
+
+fail:
+	ACPI_FREE(buffer.pointer);
+
+	return clock_num;
+}
+
+static u8 gmin_get_pmic_id_and_addr(struct device *dev)
+{
+	struct i2c_client *power = NULL;
+	static u8 pmic_i2c_addr;
+
+	if (pmic_id)
+		return pmic_i2c_addr;
+
+	if (gmin_i2c_dev_exists(dev, PMIC_ACPI_TI, &power))
+		pmic_id = PMIC_TI;
+	else if (gmin_i2c_dev_exists(dev, PMIC_ACPI_AXP, &power))
+		pmic_id = PMIC_AXP;
+	else if (gmin_i2c_dev_exists(dev, PMIC_ACPI_CRYSTALCOVE, &power))
+		pmic_id = PMIC_CRYSTALCOVE;
+	else
+		pmic_id = PMIC_REGULATOR;
+
+	pmic_i2c_addr = power ? power->addr : 0;
+	return pmic_i2c_addr;
+}
+
+static int gmin_detect_pmic(struct v4l2_subdev *subdev)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct device *dev = &client->dev;
+	u8 pmic_i2c_addr;
+
+	pmic_i2c_addr = gmin_get_pmic_id_and_addr(dev);
+	dev_info(dev, "gmin: power management provided via %s (i2c addr 0x%02x)\n",
+		 pmic_name[pmic_id], pmic_i2c_addr);
+	return pmic_i2c_addr;
+}
+
+static int gmin_subdev_add(struct gmin_subdev *gs)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(gs->subdev);
+	struct device *dev = &client->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	int ret, default_val, clock_num = -1;
+
+	dev_info(dev, "%s: ACPI path is %pfw\n", __func__, dev_fwnode(dev));
+
+	/*WA:CHT requires XTAL clock as PLL is not stable.*/
+	gs->clock_src = gmin_get_var_int(dev, false, "ClkSrc",
+				         VLV2_CLK_PLL_19P2MHZ);
+
+	/*
+	 * Get ACPI _PR0 derived clock here already because it is used
+	 * to determine the csi_port default.
+	 */
+	if (acpi_device_power_manageable(adev))
+		clock_num = atomisp_get_acpi_power(dev);
+
+	/* Compare clock to CsiPort 1 pmc-clock used in the CHT/BYT reference designs */
+	if (IS_ISP2401)
+		default_val = clock_num == 4 ? 1 : 0;
+	else
+		default_val = clock_num == 0 ? 1 : 0;
+
+	gs->csi_port = gmin_get_var_int(dev, false, "CsiPort", default_val);
+	gs->csi_lanes = gmin_get_var_int(dev, false, "CsiLanes", 1);
+
+	gs->gpio0 = gpiod_get_index(dev, NULL, 0, GPIOD_OUT_LOW);
+	if (IS_ERR(gs->gpio0))
+		gs->gpio0 = NULL;
+	else
+		dev_info(dev, "will handle gpio0 via ACPI\n");
+
+	gs->gpio1 = gpiod_get_index(dev, NULL, 1, GPIOD_OUT_LOW);
+	if (IS_ERR(gs->gpio1))
+		gs->gpio1 = NULL;
+	else
+		dev_info(dev, "will handle gpio1 via ACPI\n");
+
+	/*
+	 * Those are used only when there is an external regulator apart
+	 * from the PMIC that would be providing power supply, like on the
+	 * two cases below:
+	 *
+	 * The ECS E7 board drives camera 2.8v from an external regulator
+	 * instead of the PMIC.  There's a gmin_CamV2P8 config variable
+	 * that specifies the GPIO to handle this particular case,
+	 * but this needs a broader architecture for handling camera power.
+	 *
+	 * The CHT RVP board drives camera 1.8v from an* external regulator
+	 * instead of the PMIC just like ECS E7 board.
+	 */
+
+	gs->v1p8_gpio = gmin_get_var_int(dev, true, "V1P8GPIO", -1);
+	gs->v2p8_gpio = gmin_get_var_int(dev, true, "V2P8GPIO", -1);
+
+	/*
+	 * FIXME:
+	 *
+	 * The ACPI handling code checks for the _PR? tables in order to
+	 * know what is required to switch the device from power state
+	 * D0 (_PR0) up to D3COLD (_PR3).
+	 *
+	 * The adev->flags.power_manageable is set to true if the device
+	 * has a _PR0 table, which can be checked by calling
+	 * acpi_device_power_manageable(adev).
+	 *
+	 * However, this only says that the device can be set to power off
+	 * mode.
+	 *
+	 * At least on the DSDT tables we've seen so far, there's no _PR3,
+	 * nor _PS3 (which would have a somewhat similar effect).
+	 * So, using ACPI for power management won't work, except if adding
+	 * an ACPI override logic somewhere.
+	 *
+	 * So, at least for the existing devices we know, the check below
+	 * will always be false.
+	 */
+	if (acpi_device_can_wakeup(adev) &&
+	    acpi_device_can_poweroff(adev)) {
+		dev_info(dev,
+			 "gmin: power management provided via device PM\n");
+		return 0;
+	}
+
+	/*
+	 * The code below is here due to backward compatibility with devices
+	 * whose ACPI BIOS may not contain everything that would be needed
+	 * in order to set clocks and do power management.
+	 */
+
+	/*
+	 * According with :
+	 *   https://github.com/projectceladon/hardware-intel-kernelflinger/blob/master/doc/fastboot.md
+	 *
+	 * The "CamClk" EFI var is set via fastboot on some Android devices,
+	 * and seems to contain the number of the clock used to feed the
+	 * sensor.
+	 *
+	 * On systems with a proper ACPI table, this is given via the _PR0
+	 * power resource table. The logic below should first check if there
+	 * is a power resource already, falling back to the EFI vars detection
+	 * otherwise.
+	 */
+
+	/* If getting the clock from _PR0 above failed, fall-back to EFI and/or DMI match */
+	if (clock_num < 0)
+		clock_num = gmin_get_var_int(dev, false, "CamClk", 0);
+
+	if (clock_num < 0 || clock_num > MAX_CLK_COUNT) {
+		dev_err(dev, "Invalid clock number\n");
+		return -EINVAL;
+	}
+
+	snprintf(gmin_pmc_clk_name, sizeof(gmin_pmc_clk_name),
+		 "%s_%d", "pmc_plt_clk", clock_num);
+
+	gs->pmc_clk = devm_clk_get(dev, gmin_pmc_clk_name);
+	if (IS_ERR(gs->pmc_clk)) {
+		ret = PTR_ERR(gs->pmc_clk);
+		dev_err(dev, "Failed to get clk from %s: %d\n", gmin_pmc_clk_name, ret);
+		return ret;
+	}
+	dev_info(dev, "Will use CLK%d (%s)\n", clock_num, gmin_pmc_clk_name);
+
+	/*
+	 * The firmware might enable the clock at
+	 * boot (this information may or may not
+	 * be reflected in the enable clock register).
+	 * To change the rate we must disable the clock
+	 * first to cover these cases. Due to common
+	 * clock framework restrictions that do not allow
+	 * to disable a clock that has not been enabled,
+	 * we need to enable the clock first.
+	 */
+	ret = clk_prepare_enable(gs->pmc_clk);
+	if (!ret)
+		clk_disable_unprepare(gs->pmc_clk);
+
+	switch (pmic_id) {
+	case PMIC_REGULATOR:
+		gs->v1p8_reg = regulator_get(dev, "V1P8SX");
+		gs->v2p8_reg = regulator_get(dev, "V2P8SX");
+
+		gs->v1p2_reg = regulator_get(dev, "V1P2A");
+		gs->v2p8_vcm_reg = regulator_get(dev, "VPROG4B");
+
+		/* Note: ideally we would initialize v[12]p8_on to the
+		 * output of regulator_is_enabled(), but sadly that
+		 * API is broken with the current drivers, returning
+		 * "1" for a regulator that will then emit a
+		 * "unbalanced disable" WARNing if we try to disable
+		 * it.
+		 */
+		break;
+
+	case PMIC_AXP:
+		gs->eldo1_1p6v = gmin_get_var_int(dev, false,
+						  "eldo1_1p8v",
+						  ELDO1_1P6V);
+		gs->eldo1_sel_reg = gmin_get_var_int(dev, false,
+						     "eldo1_sel_reg",
+						     ELDO1_SEL_REG);
+		gs->eldo1_ctrl_shift = gmin_get_var_int(dev, false,
+							"eldo1_ctrl_shift",
+							ELDO1_CTRL_SHIFT);
+		gs->eldo2_1p8v = gmin_get_var_int(dev, false,
+						  "eldo2_1p8v",
+						  ELDO2_1P8V);
+		gs->eldo2_sel_reg = gmin_get_var_int(dev, false,
+						     "eldo2_sel_reg",
+						     ELDO2_SEL_REG);
+		gs->eldo2_ctrl_shift = gmin_get_var_int(dev, false,
+							"eldo2_ctrl_shift",
+							ELDO2_CTRL_SHIFT);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct gmin_subdev *find_gmin_subdev(struct v4l2_subdev *subdev)
+{
+	int i;
+
+	for (i = 0; i < MAX_SUBDEVS; i++)
+		if (gmin_subdevs[i].subdev == subdev)
+			return &gmin_subdevs[i];
+	return NULL;
+}
+
+static struct gmin_subdev *find_free_gmin_subdev_slot(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < MAX_SUBDEVS; i++)
+		if (gmin_subdevs[i].subdev == NULL)
+			return &gmin_subdevs[i];
+	return NULL;
+}
+
+static int axp_regulator_set(struct device *dev, struct gmin_subdev *gs,
+			     int sel_reg, u8 setting,
+			     int ctrl_reg, int shift, bool on)
+{
+	int ret;
+	int val;
+
+	ret = gmin_i2c_write(dev, gs->pwm_i2c_addr, sel_reg, setting, 0xff);
+	if (ret)
+		return ret;
+
+	val = on ? 1 << shift : 0;
+
+	ret = gmin_i2c_write(dev, gs->pwm_i2c_addr, ctrl_reg, val, 1 << shift);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Some boards contain a hw-bug where turning eldo2 back on after having turned
+ * it off causes the CPLM3218 ambient-light-sensor on the image-sensor's I2C bus
+ * to crash, hanging the bus. Do not turn eldo2 off on these systems.
+ */
+static const struct dmi_system_id axp_leave_eldo2_on_ids[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "TrekStor"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SurfTab duo W1 10.1 (VT4)"),
+		},
+	},
+	{ }
+};
+
+static int axp_v1p8_on(struct device *dev, struct gmin_subdev *gs)
+{
+	int ret;
+
+	ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
+				ELDO_CTRL_REG, gs->eldo2_ctrl_shift, true);
+	if (ret)
+		return ret;
+
+	/*
+	 * This sleep comes out of the gc2235 driver, which is the
+	 * only one I currently see that wants to set both 1.8v rails.
+	 */
+	usleep_range(110, 150);
+
+	ret = axp_regulator_set(dev, gs, gs->eldo1_sel_reg, gs->eldo1_1p6v,
+				ELDO_CTRL_REG, gs->eldo1_ctrl_shift, true);
+	return ret;
+}
+
+static int axp_v1p8_off(struct device *dev, struct gmin_subdev *gs)
+{
+	int ret;
+
+	ret = axp_regulator_set(dev, gs, gs->eldo1_sel_reg, gs->eldo1_1p6v,
+				ELDO_CTRL_REG, gs->eldo1_ctrl_shift, false);
+	if (ret)
+		return ret;
+
+	if (dmi_check_system(axp_leave_eldo2_on_ids))
+		return 0;
+
+	ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
+				ELDO_CTRL_REG, gs->eldo2_ctrl_shift, false);
+	return ret;
+}
+
+static int gmin_gpio0_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+
+	if (gs) {
+		gpiod_set_value(gs->gpio0, on);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static int gmin_gpio1_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+
+	if (gs) {
+		gpiod_set_value(gs->gpio1, on);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static int gmin_v1p2_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+
+	if (!gs || gs->v1p2_on == on)
+		return 0;
+	gs->v1p2_on = on;
+
+	/* use regulator for PMIC */
+	if (gs->v1p2_reg) {
+		if (on)
+			return regulator_enable(gs->v1p2_reg);
+		else
+			return regulator_disable(gs->v1p2_reg);
+	}
+
+	/* TODO:v1p2 may need to extend to other PMICs */
+
+	return -EINVAL;
+}
+
+static int gmin_v1p8_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+	int ret;
+	int value;
+	int reg;
+
+	if (!gs || gs->v1p8_on == on)
+		return 0;
+
+	if (gs->v1p8_gpio >= 0) {
+		pr_info("atomisp_gmin_platform: 1.8v power on GPIO %d\n",
+			gs->v1p8_gpio);
+		ret = gpio_request(gs->v1p8_gpio, "camera_v1p8_en");
+		if (!ret)
+			ret = gpio_direction_output(gs->v1p8_gpio, 0);
+		if (ret)
+			pr_err("V1P8 GPIO initialization failed\n");
+	}
+
+	gs->v1p8_on = on;
+
+	ret = 0;
+	mutex_lock(&gmin_regulator_mutex);
+	if (on) {
+		gmin_v1p8_enable_count++;
+		if (gmin_v1p8_enable_count > 1)
+			goto out; /* Already on */
+	} else {
+		gmin_v1p8_enable_count--;
+		if (gmin_v1p8_enable_count > 0)
+			goto out; /* Still needed */
+	}
+
+	if (gs->v1p8_gpio >= 0)
+		gpio_set_value(gs->v1p8_gpio, on);
+
+	if (gs->v1p8_reg) {
+		regulator_set_voltage(gs->v1p8_reg, 1800000, 1800000);
+		if (on)
+			ret = regulator_enable(gs->v1p8_reg);
+		else
+			ret = regulator_disable(gs->v1p8_reg);
+
+		goto out;
+	}
+
+	switch (pmic_id) {
+	case PMIC_AXP:
+		if (on)
+			ret = axp_v1p8_on(subdev->dev, gs);
+		else
+			ret = axp_v1p8_off(subdev->dev, gs);
+		break;
+	case PMIC_TI:
+		value = on ? LDO_1P8V_ON : LDO_1P8V_OFF;
+
+		ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
+				     LDO10_REG, value, 0xff);
+		break;
+	case PMIC_CRYSTALCOVE:
+		if (IS_ISP2401)
+			reg = CRYSTAL_CHT_1P8V_REG;
+		else
+			reg = CRYSTAL_BYT_1P8V_REG;
+
+		value = on ? CRYSTAL_ON : CRYSTAL_OFF;
+
+		ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
+				     reg, value, 0xff);
+		break;
+	default:
+		dev_err(subdev->dev, "Couldn't set power mode for v1p8\n");
+		ret = -EINVAL;
+	}
+
+out:
+	mutex_unlock(&gmin_regulator_mutex);
+	return ret;
+}
+
+static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+	int ret;
+	int value;
+	int reg;
+
+	if (WARN_ON(!gs))
+		return -ENODEV;
+
+	if (gs->v2p8_gpio >= 0) {
+		pr_info("atomisp_gmin_platform: 2.8v power on GPIO %d\n",
+			gs->v2p8_gpio);
+		ret = gpio_request(gs->v2p8_gpio, "camera_v2p8");
+		if (!ret)
+			ret = gpio_direction_output(gs->v2p8_gpio, 0);
+		if (ret)
+			pr_err("V2P8 GPIO initialization failed\n");
+	}
+
+	if (gs->v2p8_on == on)
+		return 0;
+	gs->v2p8_on = on;
+
+	ret = 0;
+	mutex_lock(&gmin_regulator_mutex);
+	if (on) {
+		gmin_v2p8_enable_count++;
+		if (gmin_v2p8_enable_count > 1)
+			goto out; /* Already on */
+	} else {
+		gmin_v2p8_enable_count--;
+		if (gmin_v2p8_enable_count > 0)
+			goto out; /* Still needed */
+	}
+
+	if (gs->v2p8_gpio >= 0)
+		gpio_set_value(gs->v2p8_gpio, on);
+
+	if (gs->v2p8_reg) {
+		regulator_set_voltage(gs->v2p8_reg, 2900000, 2900000);
+		if (on)
+			ret = regulator_enable(gs->v2p8_reg);
+		else
+			ret = regulator_disable(gs->v2p8_reg);
+
+		goto out;
+	}
+
+	switch (pmic_id) {
+	case PMIC_AXP:
+		ret = axp_regulator_set(subdev->dev, gs, ALDO1_SEL_REG,
+					ALDO1_2P8V, ALDO1_CTRL3_REG,
+					ALDO1_CTRL3_SHIFT, on);
+		break;
+	case PMIC_TI:
+		value = on ? LDO_2P8V_ON : LDO_2P8V_OFF;
+
+		ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
+				     LDO9_REG, value, 0xff);
+		break;
+	case PMIC_CRYSTALCOVE:
+		if (IS_ISP2401)
+			reg = CRYSTAL_CHT_2P8V_REG;
+		else
+			reg = CRYSTAL_BYT_2P8V_REG;
+
+		value = on ? CRYSTAL_ON : CRYSTAL_OFF;
+
+		ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
+				     reg, value, 0xff);
+		break;
+	default:
+		dev_err(subdev->dev, "Couldn't set power mode for v2p8\n");
+		ret = -EINVAL;
+	}
+
+out:
+	mutex_unlock(&gmin_regulator_mutex);
+	return ret;
+}
+
+static int gmin_acpi_pm_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	int ret = 0;
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+
+	/* Use the ACPI power management to control it */
+	on = !!on;
+	if (gs->clock_on == on)
+		return 0;
+
+	dev_dbg(subdev->dev, "Setting power state to %s\n",
+		on ? "on" : "off");
+
+	if (on)
+		ret = acpi_device_set_power(adev,
+					    ACPI_STATE_D0);
+	else
+		ret = acpi_device_set_power(adev,
+					    ACPI_STATE_D3_COLD);
+
+	if (!ret)
+		gs->clock_on = on;
+	else
+		dev_err(subdev->dev, "Couldn't set power state to %s\n",
+			on ? "on" : "off");
+
+	return ret;
+}
+
+static int gmin_flisclk_ctrl(struct v4l2_subdev *subdev, int on)
+{
+	int ret = 0;
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+
+	if (gs->clock_on == !!on)
+		return 0;
+
+	if (on) {
+		ret = clk_set_rate(gs->pmc_clk,
+				   gs->clock_src ? CLK_RATE_19_2MHZ : CLK_RATE_25_0MHZ);
+
+		if (ret)
+			dev_err(&client->dev, "unable to set PMC rate %d\n",
+				gs->clock_src);
+
+		ret = clk_prepare_enable(gs->pmc_clk);
+		if (ret == 0)
+			gs->clock_on = true;
+	} else {
+		clk_disable_unprepare(gs->pmc_clk);
+		gs->clock_on = false;
+	}
+
+	return ret;
+}
+
+static int camera_sensor_csi_alloc(struct v4l2_subdev *sd, u32 port, u32 lanes,
+				   u32 format, u32 bayer_order)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct camera_mipi_info *csi;
+
+	csi = kzalloc(sizeof(*csi), GFP_KERNEL);
+	if (!csi)
+		return -ENOMEM;
+
+	csi->port = port;
+	csi->num_lanes = lanes;
+	csi->input_format = format;
+	csi->raw_bayer_order = bayer_order;
+	v4l2_set_subdev_hostdata(sd, csi);
+	csi->metadata_format = ATOMISP_INPUT_FORMAT_EMBEDDED;
+	csi->metadata_effective_width = NULL;
+	dev_info(&client->dev,
+		 "camera pdata: port: %d lanes: %d order: %8.8x\n",
+		 port, lanes, bayer_order);
+
+	return 0;
+}
+
+static void camera_sensor_csi_free(struct v4l2_subdev *sd)
+{
+	struct camera_mipi_info *csi;
+
+	csi = v4l2_get_subdev_hostdata(sd);
+	kfree(csi);
+}
+
+static int gmin_csi_cfg(struct v4l2_subdev *sd, int flag)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct gmin_subdev *gs = find_gmin_subdev(sd);
+
+	if (!client || !gs)
+		return -ENODEV;
+
+	if (flag)
+		return camera_sensor_csi_alloc(sd, gs->csi_port, gs->csi_lanes,
+					       gs->csi_fmt, gs->csi_bayer);
+	camera_sensor_csi_free(sd);
+	return 0;
+}
+
+int atomisp_register_sensor_no_gmin(struct v4l2_subdev *subdev, u32 lanes,
+				    enum atomisp_input_format format,
+				    enum atomisp_bayer_order bayer_order)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+	int i, ret, clock_num, port = 0;
+
+	if (adev) {
+		/* Get ACPI _PR0 derived clock to determine the csi_port default */
+		if (acpi_device_power_manageable(adev)) {
+			clock_num = atomisp_get_acpi_power(&client->dev);
+
+			/* Compare clock to CsiPort 1 pmc-clock used in the CHT/BYT reference designs */
+			if (IS_ISP2401)
+				port = clock_num == 4 ? 1 : 0;
+			else
+				port = clock_num == 0 ? 1 : 0;
+		}
+
+		port = gmin_get_var_int(&client->dev, false, "CsiPort", port);
+		lanes = gmin_get_var_int(&client->dev, false, "CsiLanes", lanes);
+	}
+
+	for (i = 0; i < MAX_SUBDEVS; i++)
+		if (!pdata.subdevs[i].type)
+			break;
+
+	if (i >= MAX_SUBDEVS) {
+		dev_err(&client->dev, "Error too many subdevs already registered\n");
+		return -ENOMEM;
+	}
+
+	ret = camera_sensor_csi_alloc(subdev, port, lanes, format, bayer_order);
+	if (ret)
+		return ret;
+
+	pdata.subdevs[i].type = RAW_CAMERA;
+	pdata.subdevs[i].port = port;
+	pdata.subdevs[i].lanes = lanes;
+	pdata.subdevs[i].subdev = subdev;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(atomisp_register_sensor_no_gmin);
+
+void atomisp_unregister_subdev(struct v4l2_subdev *subdev)
+{
+	int i;
+
+	for (i = 0; i < MAX_SUBDEVS; i++) {
+		if (pdata.subdevs[i].subdev != subdev)
+			continue;
+
+		camera_sensor_csi_free(subdev);
+		pdata.subdevs[i].subdev = NULL;
+		pdata.subdevs[i].type = 0;
+		pdata.subdevs[i].port = 0;
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(atomisp_unregister_subdev);
+
+static struct camera_vcm_control *gmin_get_vcm_ctrl(struct v4l2_subdev *subdev,
+	char *camera_module)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct gmin_subdev *gs = find_gmin_subdev(subdev);
+	struct camera_vcm_control *vcm;
+
+	if (!client || !gs)
+		return NULL;
+
+	if (!camera_module)
+		return NULL;
+
+	mutex_lock(&vcm_lock);
+	list_for_each_entry(vcm, &vcm_devices, list) {
+		if (!strcmp(camera_module, vcm->camera_module)) {
+			mutex_unlock(&vcm_lock);
+			return vcm;
+		}
+	}
+
+	mutex_unlock(&vcm_lock);
+	return NULL;
+}
+
+static struct camera_sensor_platform_data pmic_gmin_plat = {
+	.gpio0_ctrl = gmin_gpio0_ctrl,
+	.gpio1_ctrl = gmin_gpio1_ctrl,
+	.v1p8_ctrl = gmin_v1p8_ctrl,
+	.v2p8_ctrl = gmin_v2p8_ctrl,
+	.v1p2_ctrl = gmin_v1p2_ctrl,
+	.flisclk_ctrl = gmin_flisclk_ctrl,
+	.csi_cfg = gmin_csi_cfg,
+	.get_vcm_ctrl = gmin_get_vcm_ctrl,
+};
+
+static struct camera_sensor_platform_data acpi_gmin_plat = {
+	.gpio0_ctrl = gmin_gpio0_ctrl,
+	.gpio1_ctrl = gmin_gpio1_ctrl,
+	.v1p8_ctrl = gmin_acpi_pm_ctrl,
+	.v2p8_ctrl = gmin_acpi_pm_ctrl,
+	.v1p2_ctrl = gmin_acpi_pm_ctrl,
+	.flisclk_ctrl = gmin_acpi_pm_ctrl,
+	.csi_cfg = gmin_csi_cfg,
+	.get_vcm_ctrl = gmin_get_vcm_ctrl,
+};
+
+struct camera_sensor_platform_data *
+gmin_camera_platform_data(struct v4l2_subdev *subdev,
+			  enum atomisp_input_format csi_format,
+			  enum atomisp_bayer_order csi_bayer)
+{
+	u8 pmic_i2c_addr = gmin_detect_pmic(subdev);
+	struct gmin_subdev *gs;
+
+	gs = find_free_gmin_subdev_slot();
+	gs->subdev = subdev;
+	gs->csi_fmt = csi_format;
+	gs->csi_bayer = csi_bayer;
+	gs->pwm_i2c_addr = pmic_i2c_addr;
+
+	gmin_subdev_add(gs);
+	if (gs->pmc_clk)
+		return &pmic_gmin_plat;
+	else
+		return &acpi_gmin_plat;
+}
+EXPORT_SYMBOL_GPL(gmin_camera_platform_data);
+
+int atomisp_gmin_register_vcm_control(struct camera_vcm_control *vcmCtrl)
+{
+	if (!vcmCtrl)
+		return -EINVAL;
+
+	mutex_lock(&vcm_lock);
+	list_add_tail(&vcmCtrl->list, &vcm_devices);
+	mutex_unlock(&vcm_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(atomisp_gmin_register_vcm_control);
+
+static int gmin_get_hardcoded_var(struct device *dev,
+				  struct gmin_cfg_var *varlist,
+				  const char *var8, char *out, size_t *out_len)
+{
+	struct gmin_cfg_var *gv;
+
+	for (gv = varlist; gv->name; gv++) {
+		size_t vl;
+
+		if (strcmp(var8, gv->name))
+			continue;
+
+		dev_info(dev, "Found DMI entry for '%s'\n", var8);
+
+		vl = strlen(gv->val);
+		if (vl > *out_len - 1)
+			return -ENOSPC;
+
+		strscpy(out, gv->val, *out_len);
+		*out_len = vl;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+
+static int gmin_get_config_dsm_var(struct device *dev,
+				   const char *var,
+				   char *out, size_t *out_len)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object *obj, *cur = NULL;
+	int i;
+
+	/*
+	 * The data reported by "CamClk" seems to be either 0 or 1 at the
+	 * _DSM table.
+	 *
+	 * At the ACPI tables we looked so far, this is not related to the
+	 * actual clock source for the sensor, which is given by the
+	 * _PR0 ACPI table. So, ignore it, as otherwise this will be
+	 * set to a wrong value.
+	 */
+	if (!strcmp(var, "CamClk"))
+		return -EINVAL;
+
+	/* Return on unexpected object type */
+	obj = acpi_evaluate_dsm_typed(handle, &atomisp_dsm_guid, 0, 0, NULL,
+				      ACPI_TYPE_PACKAGE);
+	if (!obj) {
+		dev_info_once(dev, "Didn't find ACPI _DSM table.\n");
+		return -EINVAL;
+	}
+
+#if 0 /* Just for debugging purposes */
+	for (i = 0; i < obj->package.count; i++) {
+		union acpi_object *cur = &obj->package.elements[i];
+
+		if (cur->type == ACPI_TYPE_INTEGER)
+			dev_info(dev, "object #%d, type %d, value: %lld\n",
+				 i, cur->type, cur->integer.value);
+		else if (cur->type == ACPI_TYPE_STRING)
+			dev_info(dev, "object #%d, type %d, string: %s\n",
+				 i, cur->type, cur->string.pointer);
+		else
+			dev_info(dev, "object #%d, type %d\n",
+				 i, cur->type);
+	}
+#endif
+
+	/* Seek for the desired var */
+	for (i = 0; i < obj->package.count - 1; i += 2) {
+		if (obj->package.elements[i].type == ACPI_TYPE_STRING &&
+		    !strcmp(obj->package.elements[i].string.pointer, var)) {
+			/* Next element should be the required value */
+			cur = &obj->package.elements[i + 1];
+			break;
+		}
+	}
+
+	if (!cur) {
+		dev_info(dev, "didn't found _DSM entry for '%s'\n", var);
+		ACPI_FREE(obj);
+		return -EINVAL;
+	}
+
+	/*
+	 * While it could be possible to have an ACPI_TYPE_INTEGER,
+	 * and read the value from cur->integer.value, the table
+	 * seen so far uses the string type. So, produce a warning
+	 * if it founds something different than string, letting it
+	 * to fall back to the old code.
+	 */
+	if (cur && cur->type != ACPI_TYPE_STRING) {
+		dev_info(dev, "found non-string _DSM entry for '%s'\n", var);
+		ACPI_FREE(obj);
+		return -EINVAL;
+	}
+
+	dev_info(dev, "found _DSM entry for '%s': %s\n", var,
+		 cur->string.pointer);
+	strscpy(out, cur->string.pointer, *out_len);
+	*out_len = strlen(out);
+
+	ACPI_FREE(obj);
+	return 0;
+}
+
+/* Retrieves a device-specific configuration variable.  The dev
+ * argument should be a device with an ACPI companion, as all
+ * configuration is based on firmware ID.
+ */
+static int gmin_get_config_var(struct device *maindev,
+			       bool is_gmin,
+			       const char *var,
+			       char *out, size_t *out_len)
+{
+	struct acpi_device *adev = ACPI_COMPANION(maindev);
+	efi_char16_t var16[CFG_VAR_NAME_MAX];
+	const struct dmi_system_id *id;
+	char var8[CFG_VAR_NAME_MAX];
+	efi_status_t status;
+	int i, ret;
+
+	if (!is_gmin && adev)
+		ret = snprintf(var8, sizeof(var8), "%s_%s", acpi_dev_name(adev), var);
+	else
+		ret = snprintf(var8, sizeof(var8), "gmin_%s", var);
+
+	if (ret < 0 || ret >= sizeof(var8) - 1)
+		return -EINVAL;
+
+	/* DMI based quirks override both the _DSM table and EFI variables */
+	id = dmi_first_match(gmin_vars);
+	if (id) {
+		ret = gmin_get_hardcoded_var(maindev, id->driver_data, var8,
+					     out, out_len);
+		if (!ret)
+			return 0;
+	}
+
+	/* For sensors, try first to use the _DSM table */
+	if (!is_gmin) {
+		ret = gmin_get_config_dsm_var(maindev, var, out, out_len);
+		if (!ret)
+			return 0;
+	}
+
+	/* Our variable names are ASCII by construction, but EFI names
+	 * are wide chars.  Convert and zero-pad.
+	 */
+	memset(var16, 0, sizeof(var16));
+	for (i = 0; i < sizeof(var8) && var8[i]; i++)
+		var16[i] = var8[i];
+
+	status = EFI_UNSUPPORTED;
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
+		status = efi.get_variable(var16, &GMIN_CFG_VAR_EFI_GUID, NULL,
+					  (unsigned long *)out_len, out);
+	if (status == EFI_SUCCESS) {
+		dev_info(maindev, "found EFI entry for '%s'\n", var8);
+	} else if (is_gmin) {
+		dev_info(maindev, "Failed to find EFI gmin variable %s\n", var8);
+	} else {
+		dev_info(maindev, "Failed to find EFI variable %s\n", var8);
+	}
+
+	return ret;
+}
+
+int gmin_get_var_int(struct device *dev, bool is_gmin, const char *var, int def)
+{
+	char val[CFG_VAR_NAME_MAX + 1];
+	size_t len = CFG_VAR_NAME_MAX;
+	long result;
+	int ret;
+
+	ret = gmin_get_config_var(dev, is_gmin, var, val, &len);
+	if (!ret) {
+		val[len] = 0;
+		ret = kstrtol(val, 0, &result);
+	} else {
+		dev_info(dev, "%s: using default (%d)\n", var, def);
+	}
+
+	return ret ? def : result;
+}
+EXPORT_SYMBOL_GPL(gmin_get_var_int);
+
+/* PCI quirk: The BYT ISP advertises PCI runtime PM but it doesn't
+ * work.  Disable so the kernel framework doesn't hang the device
+ * trying.  The driver itself does direct calls to the PUNIT to manage
+ * ISP power.
+ */
+static void isp_pm_cap_fixup(struct pci_dev *pdev)
+{
+	dev_info(&pdev->dev, "Disabling PCI power management on camera ISP\n");
+	pdev->pm_cap = 0;
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0f38, isp_pm_cap_fixup);
+
+MODULE_DESCRIPTION("Ancillary routines for binding ACPI devices");
+MODULE_LICENSE("GPL");