[v3,2/2] usb: Add driver to allow any GPIO to be used for 7211 USB signals

diff --git a/MAINTAINERS b/MAINTAINERS
index cd2aea603e03..1198acd71534 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3567,6 +3567,14 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/usb/brcm,bcm7445-ehci.yaml
 F:	drivers/usb/host/ehci-brcm.*
 
+BROADCOM BRCMSTB USB PIN MAP DRIVER
+M:	Al Cooper <alcooperx@gmail.com>
+L:	linux-usb@vger.kernel.org
+L:	bcm-kernel-feedback-list@broadcom.com
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/brcm,usb-pinmap.yaml
+F:	drivers/usb/misc/brcmstb-usb-pinmap.c
+
 BROADCOM BRCMSTB USB2 and USB3 PHY DRIVER
 M:	Al Cooper <alcooperx@gmail.com>
 L:	linux-kernel@vger.kernel.org
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 6818ea689cd9..8f1144359012 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -275,3 +275,12 @@  config USB_CHAOSKEY
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called chaoskey.
+
+config BRCM_USB_PINMAP
+	tristate "Broadcom pinmap driver support"
+	depends on (ARCH_BRCMSTB && PHY_BRCM_USB) || COMPILE_TEST
+	default ARCH_BRCMSTB && PHY_BRCM_USB
+	help
+	  This option enables support for remapping some USB external
+	  signals, which are typically on dedicated pins on the chip,
+	  to any gpio.
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index da39bddb0604..5f4e598573ab 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -31,3 +31,4 @@  obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
 
 obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
 obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
+obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
diff --git a/drivers/usb/misc/brcmstb-usb-pinmap.c b/drivers/usb/misc/brcmstb-usb-pinmap.c
new file mode 100644
index 000000000000..02144c39aaba
--- /dev/null
+++ b/drivers/usb/misc/brcmstb-usb-pinmap.c
@@ -0,0 +1,351 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Broadcom */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/kdebug.h>
+#include <linux/gpio/consumer.h>
+
+struct out_pin {
+	u32 enable_mask;
+	u32 value_mask;
+	u32 changed_mask;
+	u32 clr_changed_mask;
+	struct gpio_desc *gpiod;
+	const char *name;
+};
+
+struct in_pin {
+	u32 enable_mask;
+	u32 value_mask;
+	struct gpio_desc *gpiod;
+	const char *name;
+	struct brcmstb_usb_pinmap_data *pdata;
+};
+
+struct brcmstb_usb_pinmap_data {
+	void __iomem *regs;
+	int in_count;
+	struct in_pin *in_pins;
+	int out_count;
+	struct out_pin *out_pins;
+};
+
+
+static void pinmap_set(void __iomem *reg, u32 mask)
+{
+	u32 val;
+
+	val = readl(reg);
+	val |= mask;
+	writel(val, reg);
+}
+
+static void pinmap_unset(void __iomem *reg, u32 mask)
+{
+	u32 val;
+
+	val = readl(reg);
+	val &= ~mask;
+	writel(val, reg);
+}
+
+static void sync_in_pin(struct in_pin *pin)
+{
+	u32 val;
+
+	val = gpiod_get_value(pin->gpiod);
+	if (val)
+		pinmap_set(pin->pdata->regs, pin->value_mask);
+	else
+		pinmap_unset(pin->pdata->regs, pin->value_mask);
+}
+
+/*
+ * Interrupt from override register, propagate from override bit
+ * to GPIO.
+ */
+static irqreturn_t brcmstb_usb_pinmap_ovr_isr(int irq, void *dev_id)
+{
+	struct brcmstb_usb_pinmap_data *pdata = dev_id;
+	struct out_pin *pout;
+	u32 val;
+	u32 bit;
+	int x;
+
+	pr_debug("%s: reg: 0x%x\n", __func__, readl(pdata->regs));
+	pout = pdata->out_pins;
+	for (x = 0; x < pdata->out_count; x++) {
+		val = readl(pdata->regs);
+		if (val & pout->changed_mask) {
+			pinmap_set(pdata->regs, pout->clr_changed_mask);
+			pinmap_unset(pdata->regs, pout->clr_changed_mask);
+			bit = val & pout->value_mask;
+			gpiod_set_value(pout->gpiod, bit ? 1 : 0);
+			pr_debug("%s: %s bit changed state to %d\n",
+				 __func__, pout->name, bit ? 1 : 0);
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Interrupt from GPIO, propagate from GPIO to override bit.
+ */
+static irqreturn_t brcmstb_usb_pinmap_gpio_isr(int irq, void *dev_id)
+{
+	struct in_pin *pin = dev_id;
+
+	pr_debug("%s: %s pin changed state\n", __func__, pin->name);
+	sync_in_pin(pin);
+	return IRQ_HANDLED;
+}
+
+
+static void get_pin_counts(struct device_node *dn, int *in_count,
+			   int *out_count)
+{
+	int in;
+	int out;
+
+	*in_count = 0;
+	*out_count = 0;
+	in = of_property_count_strings(dn, "brcm,in-functions");
+	if (in < 0)
+		return;
+	out = of_property_count_strings(dn, "brcm,out-functions");
+	if (out < 0)
+		return;
+	*in_count = in;
+	*out_count = out;
+}
+
+static int parse_pins(struct device *dev, struct device_node *dn,
+		      struct brcmstb_usb_pinmap_data *pdata)
+{
+	struct out_pin *pout;
+	struct in_pin *pin;
+	int index;
+	int res;
+	int x;
+
+	pin = pdata->in_pins;
+	for (x = 0, index = 0; x < pdata->in_count; x++) {
+		pin->gpiod = devm_gpiod_get_index(dev, "in", x, GPIOD_IN);
+		if (IS_ERR(pin->gpiod)) {
+			dev_err(dev, "Error getting gpio %s\n", pin->name);
+			return PTR_ERR(pin->gpiod);
+
+		}
+		res = of_property_read_string_index(dn, "brcm,in-functions", x,
+						    &pin->name);
+		if (res < 0) {
+			dev_err(dev, "Error getting brcm,in-functions for %s\n",
+				pin->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,in-masks", index++,
+						 &pin->enable_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 1st brcm,in-masks for %s\n",
+				pin->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,in-masks", index++,
+						 &pin->value_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 2nd brcm,in-masks for %s\n",
+				pin->name);
+			return res;
+		}
+		pin->pdata = pdata;
+		pin++;
+	}
+	pout = pdata->out_pins;
+	for (x = 0, index = 0; x < pdata->out_count; x++) {
+		pout->gpiod = devm_gpiod_get_index(dev, "out", x,
+						   GPIOD_OUT_HIGH);
+		if (IS_ERR(pout->gpiod)) {
+			dev_err(dev, "Error getting gpio %s\n", pin->name);
+			return PTR_ERR(pout->gpiod);
+		}
+		res = of_property_read_string_index(dn, "brcm,out-functions", x,
+						    &pout->name);
+		if (res < 0) {
+			dev_err(dev, "Error getting brcm,out-functions for %s\n",
+				pout->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
+						 &pout->enable_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 1st brcm,out-masks for %s\n",
+				pout->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
+						 &pout->value_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 2nd brcm,out-masks for %s\n",
+				pout->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
+						 &pout->changed_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 3rd brcm,out-masks for %s\n",
+				pout->name);
+			return res;
+		}
+		res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
+						 &pout->clr_changed_mask);
+		if (res < 0) {
+			dev_err(dev, "Error getting 4th out-masks for %s\n",
+				pout->name);
+			return res;
+		}
+		pout++;
+	}
+	return 0;
+}
+
+void sync_all_pins(struct brcmstb_usb_pinmap_data *pdata)
+{
+	struct out_pin *pout;
+	struct in_pin *pin;
+	int val;
+	int x;
+
+	/*
+	 * Enable the override, clear any changed condition and
+	 * propagate the state to the GPIO for all out pins.
+	 */
+	pout = pdata->out_pins;
+	for (x = 0; x < pdata->out_count; x++) {
+		pinmap_set(pdata->regs, pout->enable_mask);
+		pinmap_set(pdata->regs, pout->clr_changed_mask);
+		pinmap_unset(pdata->regs, pout->clr_changed_mask);
+		val = readl(pdata->regs) & pout->value_mask;
+		gpiod_set_value(pout->gpiod, val ? 1 : 0);
+		pout++;
+	}
+
+	/* sync and enable all in pins. */
+	pin = pdata->in_pins;
+	for (x = 0; x < pdata->in_count; x++) {
+		sync_in_pin(pin);
+		pinmap_set(pdata->regs, pin->enable_mask);
+		pin++;
+	}
+}
+
+static int __init brcmstb_usb_pinmap_probe(struct platform_device *pdev)
+{
+	struct device_node *dn = pdev->dev.of_node;
+	struct brcmstb_usb_pinmap_data *pdata;
+	struct in_pin *pin;
+	struct resource *r;
+	int out_count;
+	int in_count;
+	int err;
+	int irq;
+	int x;
+
+	get_pin_counts(dn, &in_count, &out_count);
+	if ((in_count + out_count) == 0)
+		return -EINVAL;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	pdata = devm_kzalloc(&pdev->dev,
+			     sizeof(*pdata) +
+			     (sizeof(struct in_pin) * in_count) +
+			     (sizeof(struct out_pin) * out_count), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->in_count = in_count;
+	pdata->out_count = out_count;
+	pdata->in_pins = (struct in_pin *)(pdata + 1);
+	pdata->out_pins = (struct out_pin *)(pdata->in_pins + in_count);
+
+	pdata->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (IS_ERR(pdata->regs))
+		return PTR_ERR(pdata->regs);
+	platform_set_drvdata(pdev, pdata);
+
+	err = parse_pins(&pdev->dev, dn, pdata);
+	if (err)
+		return err;
+
+	sync_all_pins(pdata);
+
+	if (out_count) {
+
+		/* Enable interrupt for out pins */
+		irq = platform_get_irq(pdev, 0);
+		err = devm_request_irq(&pdev->dev, irq,
+				       brcmstb_usb_pinmap_ovr_isr,
+				       IRQF_TRIGGER_RISING,
+				       pdev->name, pdata);
+		if (err < 0) {
+			dev_err(&pdev->dev, "Error requesting IRQ\n");
+			return err;
+		}
+	}
+
+	for (x = 0, pin = pdata->in_pins; x < pdata->in_count; x++, pin++) {
+		irq = gpiod_to_irq(pin->gpiod);
+		if (irq < 0) {
+			dev_err(&pdev->dev, "Error getting IRQ for %s pin\n",
+				pin->name);
+			return irq;
+		}
+		err = devm_request_irq(&pdev->dev, irq,
+				       brcmstb_usb_pinmap_gpio_isr,
+				       IRQF_SHARED | IRQF_TRIGGER_RISING |
+				       IRQF_TRIGGER_FALLING,
+				       pdev->name, pin);
+		if (err < 0) {
+			dev_err(&pdev->dev, "Error requesting IRQ for %s pin\n",
+				pin->name);
+			return err;
+		}
+	}
+
+	dev_dbg(&pdev->dev, "Driver probe succeeded\n");
+	dev_dbg(&pdev->dev, "In pin count: %d, out pin count: %d\n",
+		pdata->in_count, pdata->out_count);
+	return 0;
+}
+
+
+static const struct of_device_id brcmstb_usb_pinmap_of_match[] = {
+	{ .compatible = "brcm,usb-pinmap" },
+	{ },
+};
+
+static struct platform_driver brcmstb_usb_pinmap_driver = {
+	.driver = {
+		.name	= "brcm-usb-pinmap",
+		.of_match_table = brcmstb_usb_pinmap_of_match,
+	},
+};
+
+static int __init brcmstb_usb_pinmap_init(void)
+{
+	return platform_driver_probe(&brcmstb_usb_pinmap_driver,
+				     brcmstb_usb_pinmap_probe);
+}
+
+module_init(brcmstb_usb_pinmap_init);
+MODULE_AUTHOR("Al Cooper <alcooperx@gmail.com>");
+MODULE_DESCRIPTION("Broadcom USB Pinmap Driver");
+MODULE_LICENSE("GPL");