// SPDX-License-Identifier: GPL-2.0-or-later /* * i2c support for Silicon Labs' CP2615 Digital Audio Bridge * * (c) 2021, Bence Csókás <[email protected]> */ #include <linux/errno.h> #include <linux/i2c.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/string.h> #include <linux/usb.h> /** CP2615 I/O Protocol implementation */ #define CP2615_VID … #define CP2615_PID … #define IOP_EP_IN … #define IOP_EP_OUT … #define IOP_IFN … #define IOP_ALTSETTING … #define MAX_IOP_SIZE … #define MAX_IOP_PAYLOAD_SIZE … #define MAX_I2C_SIZE … enum cp2615_iop_msg_type { … }; struct __packed cp2615_iop_msg { … }; #define PART_ID_A01 … #define PART_ID_A02 … struct __packed cp2615_iop_accessory_info { … }; struct __packed cp2615_i2c_transfer { … }; /* Possible values for struct cp2615_i2c_transfer_result.status */ enum cp2615_i2c_status { … }; struct __packed cp2615_i2c_transfer_result { … }; static int cp2615_init_iop_msg(struct cp2615_iop_msg *ret, enum cp2615_iop_msg_type msg, const void *data, size_t data_len) { … } static int cp2615_init_i2c_msg(struct cp2615_iop_msg *ret, const struct cp2615_i2c_transfer *data) { … } /* Translates status codes to Linux errno's */ static int cp2615_check_status(enum cp2615_i2c_status status) { … } /** Driver code */ static int cp2615_i2c_send(struct usb_interface *usbif, struct cp2615_i2c_transfer *i2c_w) { … } static int cp2615_i2c_recv(struct usb_interface *usbif, unsigned char tag, void *buf) { … } /* Checks if the IOP is functional by querying the part's ID */ static int cp2615_check_iop(struct usb_interface *usbif) { … } static int cp2615_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { … } static u32 cp2615_i2c_func(struct i2c_adapter *adap) { … } static const struct i2c_algorithm cp2615_i2c_algo = …; /* * This chip has some limitations: one is that the USB endpoint * can only receive 64 bytes/transfer, that leaves 54 bytes for * the I2C transfer. On top of that, EITHER read_len OR write_len * may be zero, but not both. If both are non-zero, the adapter * issues a write followed by a read. And the chip does not * support repeated START between the write and read phases. */ static struct i2c_adapter_quirks cp2615_i2c_quirks = …; static void cp2615_i2c_remove(struct usb_interface *usbif) { … } static int cp2615_i2c_probe(struct usb_interface *usbif, const struct usb_device_id *id) { … } static const struct usb_device_id id_table[] = …; MODULE_DEVICE_TABLE(usb, id_table); static struct usb_driver cp2615_i2c_driver = …; module_usb_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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