This patch adds a driver for configuration of the Microchip USB253x/xi
USB 2.0 hub controller series with USB 2.0 upstream connectivity, SMBus
configuration interface and two to four USB 2.0 downstream ports.

Furthermore add myself as a maintainer for this driver.

The datasheet can be found at the manufacturers website, see [1]. All
device-tree exposed configuration features have been tested on a i.MX6
platform with a USB2534i hub.

[1] http://ww1.microchip.com/downloads/en/AppNotes/00001801C.pdf

Signed-off-by: Christian Eggers <cegg...@arri.de>
---
 MAINTAINERS                |   7 +
 drivers/usb/misc/Kconfig   |  10 +
 drivers/usb/misc/Makefile  |   1 +
 drivers/usb/misc/usb253x.c | 834 +++++++++++++++++++++++++++++++++++++
 4 files changed, 852 insertions(+)
 create mode 100644 drivers/usb/misc/usb253x.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d53db30d1365..fe1108ba6ce7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11356,6 +11356,13 @@ S:     Maintained
 F:     Documentation/devicetree/bindings/usb/usb251xb.txt
 F:     drivers/usb/misc/usb251xb.c
 
+MICROCHIP USB253X DRIVER
+M:     Christian Eggers <cegg...@arri.de>
+L:     linux-...@vger.kernel.org
+S:     Maintained
+F:     Documentation/devicetree/bindings/usb/usb253x.yaml
+F:     drivers/usb/misc/usb253x.c
+
 MICROCHIP USBA UDC DRIVER
 M:     Cristian Birsan <cristian.bir...@microchip.com>
 L:     linux-arm-ker...@lists.infradead.org (moderated for non-subscribers)
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 4e48f8eed168..7a7b854e803a 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -242,6 +242,16 @@ config USB_HUB_USB251XB
          parameters may be set in devicetree or platform data.
          Say Y or M here if you need to configure such a device via SMBus.
 
+config USB_HUB_USB253X
+       tristate "USB253X Hub Controller Configuration Driver"
+       depends on I2C
+       select REGMAP
+       help
+         This option enables support for configuration via I2C bus of the
+         Microchip USB253x/xi USB 2.0 Hub Controller series.
+         Configuration parameters may be set in devicetree or platform data.
+         Say Y or M here if you need to configure such a device via I2C.
+
 config USB_HSIC_USB3503
        tristate "USB3503 HSIC to USB20 Driver"
        depends on I2C
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index da39bddb0604..6fd8c53841e4 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_USB_USS720)              += uss720.o
 obj-$(CONFIG_USB_SEVSEG)               += usbsevseg.o
 obj-$(CONFIG_USB_YUREX)                        += yurex.o
 obj-$(CONFIG_USB_HUB_USB251XB)         += usb251xb.o
+obj-$(CONFIG_USB_HUB_USB253X)          += usb253x.o
 obj-$(CONFIG_USB_HSIC_USB3503)         += usb3503.o
 obj-$(CONFIG_USB_HSIC_USB4604)         += usb4604.o
 obj-$(CONFIG_USB_CHAOSKEY)             += chaoskey.o
diff --git a/drivers/usb/misc/usb253x.c b/drivers/usb/misc/usb253x.c
new file mode 100644
index 000000000000..ffd72e14c3c3
--- /dev/null
+++ b/drivers/usb/misc/usb253x.c
@@ -0,0 +1,834 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Microchip USB253x USB 2.0 Hi-Speed Hub Controller
+ * Configuration via I2C.
+ *
+ * Copyright (c) 2020 ARRI Lighting
+ *
+ * This work is based on the USB251xb driver by Richard Leitner.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/nls.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/* Internal Register Set Addresses acc. to DS00001801C */
+#define USB253X_ADDR_VENDOR_ID                0x3000
+#define USB253X_ADDR_PRODUCT_ID               0x3002
+#define USB253X_ADDR_DEVICE_ID                0x3004
+#define USB253X_ADDR_HUB_CFG                  0x3006
+#define USB253X_HUB_CFG3_PRTMAP_EN            BIT(3)
+#define USB253X_HUB_CFG3_STRING_EN            BIT(0)
+#define USB253X_ADDR_NON_REMOVABLE_DEVICES    0x3009
+#define USB253X_ADDR_PORT_DISABLE_SELF        0x300A
+#define USB253X_ADDR_PORT_DISABLE_BUS         0x300B
+#define USB253X_ADDR_POWER_ON_TIME            0x3010
+#define USB253X_ADDR_LANGUAGE_ID              0x3011
+#define USB253X_ADDR_MANUFACTURER_STRING_LEN  0x3013
+#define USB253X_ADDR_PRODUCT_STRING_LEN       0x3014
+#define USB253X_ADDR_SERIAL_STRING_LEN        0x3015
+#define USB253X_ADDR_STRINGS                  0x3016
+#define USB253X_STRINGS_BUFSIZE              93  /* chars (UTF16) */
+#define USB253X_ADDR_HUB_CTRL_REMAP           0x30FD
+#define USB253X_ADDR_USB2_HUB_CTRL            0x3104
+#define USB253X_USB2_HUB_CTRL_LPM_DISABLE     BIT(1)
+#define USB253X_ADDR_INTERNAL_PORT            0x4130
+#define USB253X_INTERNAL_PORT_PORT_ENUM_DEFAULT        0b00
+#define USB253X_INTERNAL_PORT_PORT_ENUM_ALWAYS_ENABLE  0b01
+#define USB253X_INTERNAL_PORT_PORT_ENUM_ALWAYS_DISABLE 0b10
+
+#define DRIVER_NAME "usb253x"
+
+
+struct usb253x {
+       struct device *dev;
+       struct i2c_client *i2c;
+       struct regulator *vdd;
+       struct regmap *regmap;
+       u8 skip_config;
+       struct gpio_desc *gpio_reset;
+};
+
+#ifdef CONFIG_GPIOLIB
+static int usb253x_check_dev_children(struct device *dev, void *child)
+{
+       if (dev->type == &i2c_adapter_type) {
+               return device_for_each_child(dev, child,
+                                            usb253x_check_dev_children);
+       }
+
+       return (dev == child);
+}
+
+static int usb253x_check_gpio_chip(struct usb253x *hub)
+{
+       struct gpio_chip *gc = gpiod_to_chip(hub->gpio_reset);
+       struct i2c_adapter *adap = hub->i2c->adapter;
+       int ret;
+
+       if (!hub->gpio_reset)
+               return 0;
+
+       if (!gc)
+               return -EINVAL;
+
+       ret = usb253x_check_dev_children(&adap->dev, gc->parent);
+       if (ret) {
+               dev_err(hub->dev, "Reset GPIO chip is at the same i2c-bus\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+#else
+static int usb253x_check_gpio_chip(struct usb253x *hub)
+{
+       return 0;
+}
+#endif
+
+static void usb253x_reset(struct usb253x *hub, int state)
+{
+       if (state) {
+               /* During rising edge of reset, there must be no traffic on the 
i2c bus */
+               i2c_lock_bus(hub->i2c->adapter, I2C_LOCK_SEGMENT);
+               gpiod_set_value_cansleep(hub->gpio_reset, 1);
+               /* Wait for i2c logic to come up (hub seems to require ~210 ms 
if
+                * RESET_N pulse was longer than 25 ms)
+                */
+               msleep(250);
+               i2c_unlock_bus(hub->i2c->adapter, I2C_LOCK_SEGMENT);
+       } else {
+               gpiod_set_value_cansleep(hub->gpio_reset, 0);
+               /* minimum reset pulse width from data sheet is 5 us */
+               usleep_range(5, 10);
+       }
+}
+
+static void usb253x_get_ports_field(struct usb253x *hub,
+                                   const char *prop_name, u8 port_cnt,
+                                   u8 *fld)
+{
+       struct device *dev = hub->dev;
+       struct property *prop;
+       const __be32 *p;
+       u32 port;
+
+       of_property_for_each_u32(dev->of_node, prop_name, prop, p, port) {
+               if ((port >= 1) && (port <= port_cnt))
+                       *fld |= BIT(port);
+               else
+                       dev_warn(dev, "port %u doesn't exist\n", port);
+       }
+}
+
+static int usb253x_connect(struct usb253x *hub)
+{
+       struct device *dev = hub->dev;
+       struct device_node *np = dev->of_node;
+       int err;
+       char attach_buffer[3];
+
+       usb253x_reset(hub, 1);
+
+       if (hub->skip_config) {
+               dev_info(dev, "Skip hub configuration, only attach.\n");
+       } else {
+               u16 vendor_id, product_id, device_id, lang_id;
+               u8 hub_cfg[3];
+               u32 property_u32;
+               char const *manufacturer;
+               char const *product;
+               char const *serial;
+               u8 non_rem_dev = 0;
+               u8 port_disable_sp = 0;
+               u8 port_disable_bp = 0;
+               wchar_t strings[USB253X_STRINGS_BUFSIZE];
+               int strings_used = 0;
+               u32 hub_controller_port = 0;
+
+               memset(strings, 0, sizeof(strings));
+
+               if (!of_property_read_u16_array(np, "vendor-id", &vendor_id, 
1)) {
+                       char buffer[] = { vendor_id >> 8, vendor_id };
+
+                       err = regmap_bulk_write(hub->regmap, 
USB253X_ADDR_VENDOR_ID,
+                                       buffer, ARRAY_SIZE(buffer));
+                       if (err) {
+                               dev_err(dev, "Setting vendor id failed: %d\n", 
err);
+                               return err;
+                       }
+               }
+
+               if (!of_property_read_u16_array(np, "product-id", &product_id, 
1)) {
+                       char buffer[] = { product_id >> 8, product_id };
+
+                       err = regmap_bulk_write(hub->regmap, 
USB253X_ADDR_PRODUCT_ID,
+                                       buffer, ARRAY_SIZE(buffer));
+                       if (err) {
+                               dev_err(dev, "Setting product id failed: %d\n", 
err);
+                               return err;
+                       }
+               }
+
+               if (!of_property_read_u16_array(np, "device-id", &device_id, 
1)) {
+                       char buffer[] = { device_id >> 8, device_id };
+
+                       err = regmap_bulk_write(hub->regmap, 
USB253X_ADDR_DEVICE_ID,
+                                       buffer, ARRAY_SIZE(buffer));
+                       if (err) {
+                               dev_err(dev, "Setting device id failed: %d\n", 
err);
+                               return err;
+                       }
+               }
+
+               err = regmap_bulk_read(hub->regmap, USB253X_ADDR_HUB_CFG,
+                               hub_cfg, ARRAY_SIZE(hub_cfg));
+               if (err) {
+                       dev_err(dev, "Reading hub cfg failed: %d\n", err);
+                       return err;
+               }
+
+               if (of_get_property(np, "self-powered", NULL)) {
+                       hub_cfg[0] |= BIT(7);
+
+                       /* Configure Over-Current sens when self-powered */
+                       hub_cfg[0] &= ~BIT(2);
+                       if (of_get_property(np, "ganged-sensing", NULL))
+                               hub_cfg[0] &= ~BIT(1);
+                       else if (of_get_property(np, "individual-sensing", 
NULL))
+                               hub_cfg[0] |= BIT(1);
+               } else if (of_get_property(np, "bus-powered", NULL)) {
+                       hub_cfg[0] &= ~BIT(7);
+
+                       /* Disable Over-Current sense when bus-powered */
+                       hub_cfg[0] |= BIT(2);
+               }
+
+               if (of_get_property(np, "disable-hi-speed", NULL))
+                       hub_cfg[0] |= BIT(5);
+
+               if (of_get_property(np, "multi-tt", NULL))
+                       hub_cfg[0] |= BIT(4);
+               else if (of_get_property(np, "single-tt", NULL))
+                       hub_cfg[0] &= ~BIT(4);
+
+               if (of_get_property(np, "disable-eop", NULL))
+                       hub_cfg[0] |= BIT(3);
+
+               if (of_get_property(np, "individual-port-switching", NULL))
+                       hub_cfg[0] |= BIT(0);
+               else if (of_get_property(np, "ganged-port-switching", NULL))
+                       hub_cfg[0] &= ~BIT(0);
+
+               if (of_get_property(np, "dynamic-power-switching", NULL))
+                       hub_cfg[1] |= BIT(7);
+
+               if (!of_property_read_u32(np, "oc-delay-us", &property_u32)) {
+                       if (property_u32 == 100) {
+                               /* 100 us*/
+                               hub_cfg[1] &= ~BIT(5);
+                               hub_cfg[1] &= ~BIT(4);
+                       } else if (property_u32 == 4000) {
+                               /* 4 ms */
+                               hub_cfg[1] &= ~BIT(5);
+                               hub_cfg[1] |= BIT(4);
+                       } else if (property_u32 == 16000) {
+                               /* 16 ms */
+                               hub_cfg[1] |= BIT(5);
+                               hub_cfg[1] |= BIT(4);
+                       } else {
+                               /* 8 ms (DEFAULT) */
+                               hub_cfg[1] |= BIT(5);
+                               hub_cfg[1] &= ~BIT(4);
+                       }
+               }
+
+               if (of_get_property(np, "compound-device", NULL))
+                       hub_cfg[1] |= BIT(3);
+
+               if (of_get_property(np, "port-mapping-mode", NULL))
+                       hub_cfg[2] |= USB253X_HUB_CFG3_PRTMAP_EN;
+
+               /* hub controller will only work when port mapping is enabled 
and
+                * controller port is mapped
+                */
+               if (!of_property_read_u32(np, "hub-controller-port",
+                               &hub_controller_port))
+                       hub_cfg[2] |= USB253X_HUB_CFG3_PRTMAP_EN;
+
+               /* port mapping requires that Link Power Management is disabled 
*/
+               if (hub_cfg[2] & USB253X_HUB_CFG3_PRTMAP_EN) {
+                       unsigned int usb2_hub_ctrl;
+
+                       /* Disable Link Power Management */
+                       err = regmap_read(hub->regmap, 
USB253X_ADDR_USB2_HUB_CTRL,
+                                       &usb2_hub_ctrl);
+                       if (err) {
+                               dev_err(dev, "Reading USB2 Hub Control failed: 
%d\n", err);
+                               return err;
+                       }
+
+                       usb2_hub_ctrl |= USB253X_USB2_HUB_CTRL_LPM_DISABLE;
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_USB2_HUB_CTRL,
+                                       usb2_hub_ctrl);
+                       if (err) {
+                               dev_err(dev, "Writing USB2 Hub Control failed: 
%d\n", err);
+                               return err;
+                       }
+               }
+
+               manufacturer = of_get_property(np, "manufacturer", NULL);
+               product = of_get_property(np, "product", NULL);
+               serial = of_get_property(np, "serial", NULL);
+
+               if (manufacturer || product || serial)
+                       hub_cfg[2] |= USB253X_HUB_CFG3_STRING_EN;
+
+               err = regmap_bulk_write(hub->regmap, USB253X_ADDR_HUB_CFG,
+                               hub_cfg, ARRAY_SIZE(hub_cfg));
+               if (err) {
+                       dev_err(dev, "Setting hub cfg failed: %d\n", err);
+                       return err;
+               }
+
+               usb253x_get_ports_field(hub, "non-removable-ports", 4, 
&non_rem_dev);
+               err = regmap_write(hub->regmap, 
USB253X_ADDR_NON_REMOVABLE_DEVICES,
+                               non_rem_dev);
+               if (err) {
+                       dev_err(dev, "Setting non removable devices failed: 
%d\n", err);
+                       return err;
+               }
+
+               usb253x_get_ports_field(hub, "sp-disabled-ports", 4, 
&port_disable_sp);
+               err = regmap_write(hub->regmap, USB253X_ADDR_PORT_DISABLE_SELF,
+                               port_disable_sp);
+               if (err) {
+                       dev_err(dev, "Setting port disable self powered failed: 
%d\n", err);
+                       return err;
+               }
+
+               usb253x_get_ports_field(hub, "bp-disabled-ports", 4, 
&port_disable_bp);
+               err = regmap_write(hub->regmap, USB253X_ADDR_PORT_DISABLE_BUS,
+                               port_disable_bp);
+               if (err) {
+                       dev_err(dev, "Setting port disable powered powered 
failed: %d\n", err);
+                       return err;
+               }
+
+               if (!of_property_read_u32(np, "power-on-time-ms", 
&property_u32)) {
+                       u8 power_on_time = min_t(u8, property_u32 / 2, 255);
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_POWER_ON_TIME,
+                                       power_on_time);
+                       if (err) {
+                               dev_err(dev, "Setting port disable powered 
powered failed: %d\n",
+                                               err);
+                               return err;
+                       }
+               }
+
+               if (!of_property_read_u16_array(np, "language-id", &lang_id, 
1)) {
+                       char buffer[] = { lang_id >> 8, lang_id };
+
+                       err = regmap_bulk_write(hub->regmap, 
USB253X_ADDR_LANGUAGE_ID,
+                                       buffer, ARRAY_SIZE(buffer));
+                       if (err) {
+                               dev_err(dev, "Setting language id failed: 
%d\n", err);
+                               return err;
+                       }
+               }
+
+               if (manufacturer) {
+                       u8 manufacturer_len = utf8s_to_utf16s(manufacturer, 
strlen(manufacturer),
+                                       UTF16_LITTLE_ENDIAN,
+                                       &strings[strings_used],
+                                       USB253X_STRINGS_BUFSIZE - strings_used);
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_MANUFACTURER_STRING_LEN,
+                                       manufacturer_len);
+                       if (err) {
+                               dev_err(dev, "Setting manufacturer string 
length failed: %d\n",
+                                               err);
+                               return err;
+                       }
+
+                       strings_used += manufacturer_len;
+               }
+
+               if (product) {
+                       u8 product_len = utf8s_to_utf16s(product, 
strlen(product),
+                                       UTF16_LITTLE_ENDIAN,
+                                       &strings[strings_used],
+                                       USB253X_STRINGS_BUFSIZE - strings_used);
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_PRODUCT_STRING_LEN,
+                                       product_len);
+                       if (err) {
+                               dev_err(dev, "Setting product string length 
failed: %d\n", err);
+                               return err;
+                       }
+
+                       strings_used += product_len;
+               }
+
+               if (serial) {
+                       u8 serial_len = utf8s_to_utf16s(serial, strlen(serial),
+                                       UTF16_LITTLE_ENDIAN,
+                                       &strings[strings_used],
+                                       USB253X_STRINGS_BUFSIZE - strings_used);
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_SERIAL_STRING_LEN,
+                                       serial_len);
+                       if (err) {
+                               dev_err(dev, "Setting serial string length 
failed: %d\n", err);
+                               return err;
+                       }
+
+                       strings_used += serial_len;
+               }
+
+               err = regmap_bulk_write(hub->regmap, USB253X_ADDR_STRINGS,
+                               strings, sizeof(strings));
+               if (err) {
+                       dev_err(dev, "Setting strings failed: %d\n", err);
+                       return err;
+               }
+
+               if (hub_controller_port != 0) {
+                       /* Writes to this register are disabled unless 
PRTMAP_EN bit in
+                        * HUB_CFG_3 is set.
+                        */
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_HUB_CTRL_REMAP,
+                                       hub_controller_port);
+                       if (err) {
+                               dev_err(dev, "Setting hub controller remap 
failed: %d\n", err);
+                               return err;
+                       }
+
+                       err = regmap_write(hub->regmap, 
USB253X_ADDR_INTERNAL_PORT,
+                                       
USB253X_INTERNAL_PORT_PORT_ENUM_ALWAYS_ENABLE);
+                       if (err) {
+                               dev_err(dev, "Setting internal port failed: 
%d\n", err);
+                               return err;
+                       }
+               }
+       }
+
+#ifdef DEBUG
+       {
+               char *buffer = kzalloc(0x5000, GFP_KERNEL);
+
+               err = regmap_bulk_read(hub->regmap, 0, buffer, 0x5000);
+               print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buffer, 0x5000);
+               kfree(buffer);
+       }
+#endif
+
+       /*
+        *  attach
+        */
+       attach_buffer[0] = 0xAA;   /* USB attach (high byte) */
+       attach_buffer[1] = 0x55;   /* USB attach (low byte) */
+       attach_buffer[2] = 0x00;   /* terminator */
+
+       err = i2c_master_send(hub->i2c, attach_buffer, 3);
+       if (err != 3) {
+               dev_err(dev, "attaching hub failed: %d\n", err);
+               return err;
+       }
+
+       dev_info(dev, "Hub configuration was successful.\n");
+       return 0;
+
+}
+
+#ifdef CONFIG_OF
+static int usb253x_get_ofdata(struct usb253x *hub)
+{
+       struct device *dev = hub->dev;
+       struct device_node *np = dev->of_node;
+
+       if (!np) {
+               dev_err(dev, "failed to get ofdata\n");
+               return -ENODEV;
+       }
+
+       if (of_get_property(np, "skip-config", NULL))
+               hub->skip_config = 1;
+       else
+               hub->skip_config = 0;
+
+       hub->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+       if (IS_ERR(hub->gpio_reset))
+               return PTR_ERR(hub->gpio_reset);
+
+       return 0;
+}
+
+static const struct of_device_id usb253x_of_match[] = {
+       { .compatible = "microchip,usb2532",  },
+       { .compatible = "microchip,usb2532i", },
+       { .compatible = "microchip,usb2533",  },
+       { .compatible = "microchip,usb2533i", },
+       { .compatible = "microchip,usb2534",  },
+       { .compatible = "microchip,usb2534i", },
+       { .compatible = "microchip,usb3613",  },
+       { .compatible = "microchip,usb3613i", },
+       { .compatible = "microchip,usb3813",  },
+       { .compatible = "microchip,usb3813i", },
+       { .compatible = "microchip,usb4604",  },
+       { .compatible = "microchip,usb4604i", },
+       { .compatible = "microchip,usb4624",  },
+       { .compatible = "microchip,usb4624i", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, usb253x_of_match);
+#else /* CONFIG_OF */
+static int usb253x_get_ofdata(struct usb253x *hub)
+{
+       return 0;
+}
+#endif /* CONFIG_OF */
+
+static void usb253x_regulator_disable_action(void *data)
+{
+       struct usb253x *hub = data;
+
+       regulator_disable(hub->vdd);
+}
+
+static int usb253x_probe(struct usb253x *hub)
+{
+       struct device *dev = hub->dev;
+       struct device_node *np = dev->of_node;
+       int err;
+
+       if (np) {
+               err = usb253x_get_ofdata(hub);
+               if (err) {
+                       dev_err(dev, "failed to get ofdata: %d\n", err);
+                       return err;
+               }
+       }
+
+       /*
+        * usb253x SMBus-slave SCL lane is muxed with CFG_SEL0 pin. So if anyone
+        * tries to work with the bus at the moment the hub reset is released,
+        * it may cause an invalid config being latched by usb253x. Particularly
+        * one of the config modes makes the hub loading a default registers
+        * value without SMBus-slave interface activation. If the hub
+        * accidentally gets this mode, this will cause the driver SMBus-
+        * functions failure. Normally we could just lock the SMBus-segment the
+        * hub i2c-interface resides for the device-specific reset timing. But
+        * the GPIO controller, which is used to handle the hub reset, might be
+        * placed at the same i2c-bus segment. In this case an error should be
+        * returned since we can't safely use the GPIO controller to clear the
+        * reset state (it may affect the hub configuration) and we can't lock
+        * the i2c-bus segment (it will cause a deadlock).
+        */
+       err = usb253x_check_gpio_chip(hub);
+       if (err)
+               return err;
+
+       hub->vdd = devm_regulator_get(dev, "vdd");
+       if (IS_ERR(hub->vdd))
+               return PTR_ERR(hub->vdd);
+
+       err = regulator_enable(hub->vdd);
+       if (err)
+               return err;
+
+       err = devm_add_action_or_reset(dev,
+                                      usb253x_regulator_disable_action, hub);
+       if (err)
+               return err;
+
+       err = usb253x_connect(hub);
+       if (err) {
+               dev_err(dev, "Failed to connect hub (%d)\n", err);
+               return err;
+       }
+
+       dev_info(dev, "Hub probed successfully\n");
+
+       return 0;
+}
+
+static int usb253x_i2c_gather_write(void *context,
+               const void *reg, size_t reg_len,
+               const void *val, size_t val_len)
+{
+       struct i2c_client *i2c = (struct i2c_client *)context;
+       size_t frame_len = val_len + 7;
+       char *buffer;
+       int err;
+
+       if (WARN_ON(reg_len != 2))
+               return -EINVAL;
+
+       buffer = kmalloc(frame_len, GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
+
+       buffer[0] = 0x00;                 /* Memory address (high byte) */
+       buffer[1] = 0x00;                 /* Memory address (low byte) */
+       buffer[2] = val_len + 4;          /* Number of bytes to write to memory 
*/
+       buffer[3] = 0x00;                 /* Register Write */
+       buffer[4] = val_len;              /* Write val_len data bytes */
+       buffer[5] = *((const char *)reg + 0);   /* Register address (high byte) 
*/
+       buffer[6] = *((const char *)reg + 1);   /* Register address (low byte) 
*/
+       memcpy(&buffer[7], val, val_len);
+
+       err = i2c_master_send(i2c, buffer, frame_len);
+       if (err != (int)frame_len) {
+               dev_err(&i2c->dev, "Writing to hub memory failed: %d\n", err);
+               goto error_kfree;
+       }
+
+       buffer[0] = 0x99;   /* Command (high byte) */
+       buffer[1] = 0x37;   /* Command (low byte) */
+       buffer[2] = 0x00;   /* Termination */
+       frame_len = 3;
+
+       err = i2c_master_send(i2c, buffer, frame_len);
+       if (err != (int)frame_len) {
+               dev_err(&i2c->dev, "Accessing configuration data failed: %d\n", 
err);
+               goto error_kfree;
+       }
+
+       err = 0;
+
+error_kfree:
+       kfree(buffer);
+       return err;
+}
+
+/* regmap puts address into data[0] and data[1]; value is in data[2] */
+static int usb253x_i2c_write(void *context, const void *data, size_t count)
+{
+       if (WARN_ON(count != 3))
+               return -EINVAL;
+
+       return usb253x_i2c_gather_write(context, data, 2, data + 2, 1);
+}
+
+static int usb253x_i2c_read(void *context, const void *reg_buf, size_t 
reg_size,
+               void *val_buf, size_t val_size)
+{
+       struct i2c_client *i2c = (struct i2c_client *)context;
+       char *tx, *rx;
+       int err;
+
+       if (WARN_ON(reg_size != 2)) {
+               err =  -EINVAL;
+               goto error_return;
+       }
+
+       tx = kmalloc(7, GFP_KERNEL);
+       if (!tx) {
+               err = -ENOMEM;
+               goto error_return;
+       }
+
+       rx = kmalloc(1 + val_size, GFP_KERNEL);
+       if (!rx) {
+               err = -ENOMEM;
+               goto error_free_tx;
+       }
+
+       tx[0] = 0x00;                 /* Memory address (high byte) */
+       tx[1] = 0x00;                 /* Memory address (low byte) */
+       tx[2] = 4;                    /* Number of bytes to write to memory */
+       tx[3] = 0x01;                 /* Register Read */
+       tx[4] = val_size;             /* Read val_size data bytes */
+       tx[5] = *((const char *)reg_buf + 0);   /* Register address (high byte) 
*/
+       tx[6] = *((const char *)reg_buf + 1);   /* Register address (low byte) 
*/
+
+       err = i2c_master_send(i2c, tx, 7);
+       if (err != 7) {
+               dev_err(&i2c->dev, "Writing to hub memory failed: %d\n", err);
+               goto error_free_rx;
+       }
+
+       tx[0] = 0x99;   /* Command (high byte) */
+       tx[1] = 0x37;   /* Command (low byte) */
+       tx[2] = 0x00;   /* Termination */
+
+       err = i2c_master_send(i2c, tx, 3);
+       if (err != 3) {
+               dev_err(&i2c->dev, "Accessing configuration data failed: %d\n", 
err);
+               goto error_free_rx;
+       }
+
+       /* Read from hub memory address 4 (according to application note) */
+       tx[0] = 0x00;    /* Memory address (high byte) */
+       tx[1] = 0x04;    /* Memory address (low byte) */
+
+       {
+               struct i2c_msg msgs[] = {
+                       {
+                               .addr = i2c->addr, .flags = 0,
+                               .len  =         2, .buf = tx
+                       },
+                       {
+                               .addr = i2c->addr, .flags = I2C_M_RD,
+                               .len = 1 + val_size, .buf = rx
+                       },
+               };
+
+               err = i2c_transfer(i2c->adapter, msgs, ARRAY_SIZE(msgs));
+               if (err < 0) {
+                       dev_err(&i2c->dev, "Reading from hub memory failed: 
%d\n", err);
+                       goto error_free_rx;
+               }
+       }
+
+       WARN_ON(rx[0] < val_size);
+
+       memcpy(val_buf, &rx[1], val_size);
+
+       err = 0;
+
+error_free_rx:
+       kfree(rx);
+error_free_tx:
+       kfree(tx);
+error_return:
+       return err;
+}
+
+/*
+ * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
+ * is that accesses to the USB253x configuration memory have to be wrapped into
+ * a special protocol.
+ */
+static const struct regmap_bus usb253x_i2c_regmap = {
+       .write         = usb253x_i2c_write,
+       .gather_write  = usb253x_i2c_gather_write,
+       .read          = usb253x_i2c_read,
+       .max_raw_read  = 128,
+       .max_raw_write = 128,
+};
+
+/* Avoid reading bigger dead ranges inside hubs memory.  Same table for
+ * read and write.
+ */
+static const struct regmap_range usb253x_regmap_yes_ranges[] = {
+       { .range_min = 0x0800, .range_max = 0x09ff },
+       { .range_min = 0x3000, .range_max = 0x31ff },
+       { .range_min = 0x3C00, .range_max = 0x3cff },
+       { .range_min = 0x4100, .range_max = 0x42ff },
+       { .range_min = 0x6000, .range_max = 0x72ff },
+};
+
+static const struct regmap_access_table usb253x_regmap_access_table = {
+       .yes_ranges   = usb253x_regmap_yes_ranges,
+       .n_yes_ranges = ARRAY_SIZE(usb253x_regmap_yes_ranges),
+};
+
+static int usb253x_i2c_probe(struct i2c_client *i2c,
+                             const struct i2c_device_id *id __always_unused)
+{
+       struct usb253x *hub;
+       struct regmap_config regmap_cfg = {
+               .name            = "usb253x_config_mem",
+               .reg_bits        = 16,
+               .val_bits        = 8,
+               .max_register    = 0x7fff,
+               .wr_table        = &usb253x_regmap_access_table,
+               .rd_table        = &usb253x_regmap_access_table,
+               .can_multi_write = 1,
+       };
+
+       hub = devm_kzalloc(&i2c->dev, sizeof(struct usb253x), GFP_KERNEL);
+       if (!hub)
+               return -ENOMEM;
+
+       i2c_set_clientdata(i2c, hub);
+       hub->dev = &i2c->dev;
+       hub->i2c = i2c;
+       hub->regmap = devm_regmap_init(&i2c->dev, &usb253x_i2c_regmap, i2c,
+                       &regmap_cfg);
+       if (IS_ERR(hub->regmap))
+               return PTR_ERR(hub->regmap);
+
+       return usb253x_probe(hub);
+}
+
+static int usb253x_i2c_remove(struct i2c_client *i2c)
+{
+       struct usb253x *hub = i2c_get_clientdata(i2c);
+
+       usb253x_reset(hub, 0);
+
+       return 0;
+};
+
+static int __maybe_unused usb253x_suspend(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct usb253x *hub = i2c_get_clientdata(client);
+
+       return regulator_disable(hub->vdd);
+}
+
+static int __maybe_unused usb253x_resume(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct usb253x *hub = i2c_get_clientdata(client);
+       int err;
+
+       err = regulator_enable(hub->vdd);
+       if (err)
+               return err;
+
+       return usb253x_connect(hub);
+}
+
+static SIMPLE_DEV_PM_OPS(usb253x_pm_ops, usb253x_suspend, usb253x_resume);
+
+static const struct i2c_device_id usb253x_id[] = {
+       { "usb2532", 0 },
+       { "usb2532i", 0 },
+       { "usb2533", 0 },
+       { "usb2533i", 0 },
+       { "usb2534", 0 },
+       { "usb2534i", 0 },
+       { "usb3613", 0 },
+       { "usb3613i", 0 },
+       { "usb3813", 0 },
+       { "usb3813i", 0 },
+       { "usb4604", 0 },
+       { "usb4604i", 0 },
+       { "usb4624", 0 },
+       { "usb4624i", 0 },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, usb253x_id);
+
+static struct i2c_driver usb253x_i2c_driver = {
+       .driver = {
+               .name = DRIVER_NAME,
+               .of_match_table = of_match_ptr(usb253x_of_match),
+               .pm = &usb253x_pm_ops,
+       },
+       .probe    = usb253x_i2c_probe,
+       .remove   = usb253x_i2c_remove,
+       .id_table = usb253x_id,
+};
+
+module_i2c_driver(usb253x_i2c_driver);
+
+MODULE_AUTHOR("Christian Eggers <cegg...@arri.de>");
+MODULE_DESCRIPTION("USB253x/xi USB 2.0 Hub Controller Driver");
+MODULE_LICENSE("GPL");
-- 
Christian Eggers
Embedded software developer

Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: 
HRA 57918
Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: 
HRB 54477
Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; 
Markus Zeiler

Reply via email to