Message ID | 1409930279-1382-2-git-send-email-octavian.purdila@intel.com |
---|---|
State | Superseded, archived |
Headers | show |
On Fri, Sep 05, 2014 at 06:17:57PM +0300, Octavian Purdila wrote: > This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO > Master Adapter DLN-2. Details about the device can be found here: > > https://www.diolan.com/i2c/i2c_interface.html. > > Information about the USB protocol can be found in the Programmer's > Reference Manual [1], see section 1.7. > > Because the hardware has a single transmit endpoint and a single > receive endpoint the communication between the various DLN2 drivers > and the hardware will be muxed/demuxed by this driver. > > Each DLN2 module will be identified by the handle field within the DLN2 > message header. If a DLN2 module issues multiple commands in parallel > they will be identified by the echo counter field in the message header. > > The DLN2 modules can use the dln2_transfer() function to issue a > command and wait for its response. They can also register a callback > that is going to be called when a specific event id is generated by > the device (e.g. GPIO interrupts). The device uses handle 0 for > sending events. > > [1] https://www.diolan.com/downloads/dln-api-manual.pdf > > Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> > --- > drivers/mfd/Kconfig | 9 + > drivers/mfd/Makefile | 1 + > drivers/mfd/dln2.c | 653 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/dln2.h | 61 +++++ > 4 files changed, 724 insertions(+) > create mode 100644 drivers/mfd/dln2.c > create mode 100644 include/linux/mfd/dln2.h First of all, this is much cleaner than the first non-MFD version. I'll have a look at the subdrivers shortly as well. > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index de5abf2..7bcf895 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -183,6 +183,15 @@ config MFD_DA9063 > Additional drivers must be enabled in order to use the functionality > of the device. > > +config MFD_DLN2 > + tristate "Diolan DLN2 support" > + select MFD_CORE > + depends on USB > + help > + This adds support for Diolan USB-I2C/SPI/GPIO Master Adapter DLN-2. > + Additional drivers must be enabled in order to use the functionality > + of the device. > + > config MFD_MC13XXX > tristate > depends on (SPI_MASTER || I2C) > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index f001487..591988d 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711) += as3711.o > obj-$(CONFIG_MFD_AS3722) += as3722.o > obj-$(CONFIG_MFD_STW481X) += stw481x.o > obj-$(CONFIG_MFD_IPAQ_MICRO) += ipaq-micro.o > +obj-$(CONFIG_MFD_DLN2) += dln2.o > > intel-soc-pmic-objs := intel_soc_pmic_core.o intel_soc_pmic_crc.o > obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o > diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c > new file mode 100644 > index 0000000..81ff58e > --- /dev/null > +++ b/drivers/mfd/dln2.c > @@ -0,0 +1,653 @@ > +/* > + * Driver for the Diolan DLN-2 USB adapter > + * > + * Copyright (c) 2014 Intel Corporation > + * > + * Derived from: > + * i2c-diolan-u2c.c > + * Copyright (c) 2010-2011 Ericsson AB > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License as > + * published by the Free Software Foundation, version 2. > + */ > + > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <linux/module.h> > +#include <linux/types.h> > +#include <linux/slab.h> > +#include <linux/usb.h> > +#include <linux/i2c.h> > +#include <linux/mutex.h> > +#include <linux/platform_device.h> > +#include <linux/mfd/core.h> > +#include <linux/mfd/dln2.h> > + > +#define DRIVER_NAME "usb-dln2" > + > +struct dln2_header { > + __le16 size; > + __le16 id; > + __le16 echo; > + __le16 handle; > +} __packed; > + > +struct dln2_response { > + struct dln2_header hdr; > + __le16 result; > +} __packed; > + > +#define DLN2_GENERIC_MODULE_ID 0x00 > +#define DLN2_GENERIC_CMD(cmd) DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID) > +#define CMD_GET_DEVICE_VER DLN2_GENERIC_CMD(0x30) > +#define CMD_GET_DEVICE_SN DLN2_GENERIC_CMD(0x31) > + > +#define DLN2_HW_ID 0x200 > +#define DLN2_USB_TIMEOUT 200 /* in ms */ > +#define DLN2_MAX_RX_SLOTS 16 > +#define DLN2_MAX_MODULES 5 > +#define DLN2_MAX_URBS 16 > + > +#define DLN2_HANDLE_GPIO_EVENT 0 Just DLN2_HANDLE_EVENT? > +#define DLN2_HANDLE_CTRL 1 > +#define DLN2_HANDLE_GPIO 2 > +#define DLN2_HANDLE_I2C 3 > + > +/* Receive context used between the receive demultiplexer and the > + * transfer routine. While sending a request the transfer routine > + * will look for a free receive context and use it to wait for a > + * response and to receive the URB and thus the response data. */ The recommended style for multi-line comments is /* * ... */ This applies to all three patches. > +struct dln2_rx_context { > + struct completion done; > + struct urb *urb; > + bool connected; > +}; > + > +/* Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We > + * use the handle header field to indentify the module in > + * dln2_dev.mod_rx_slots and then the echo header field to index the > + * slots field and find the receive context for a particular > + * request. */ > +struct dln2_mod_rx_slots { > + /* RX slots bitmap */ > + unsigned long bmap; > + > + /* used to wait for a free RX slot */ > + wait_queue_head_t wq; > + > + /* used to wait for an RX operation to complete */ > + struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS]; > + > + /* avoid races between free_rx_slot and dln2_rx_transfer_cb */ > + spinlock_t lock; > +}; > + > +struct dln2_dev { > + struct usb_device *usb_dev; > + struct usb_interface *interface; > + u8 ep_in; > + u8 ep_out; > + > + struct urb *rx_urb[DLN2_MAX_URBS]; > + void *rx_buf[DLN2_MAX_URBS]; > + > + struct dln2_mod_rx_slots mod_rx_slots[DLN2_MAX_MODULES]; > + > + struct list_head rx_cb_list; > + spinlock_t rx_cb_lock; > +}; > + > +static bool find_free_slot(struct dln2_mod_rx_slots *rxs, int *slot) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&rxs->lock, flags); > + > + *slot = find_first_zero_bit(&rxs->bmap, DLN2_MAX_RX_SLOTS); > + > + if (*slot < DLN2_MAX_RX_SLOTS) { > + struct dln2_rx_context *rxc = &rxs->slots[*slot]; > + > + init_completion(&rxc->done); Initialise the completions when you allocate them (and there's no need to re-init here). > + set_bit(*slot, &rxs->bmap); > + rxc->connected = true; > + } > + > + spin_unlock_irqrestore(&rxs->lock, flags); > + > + return *slot < DLN2_MAX_RX_SLOTS; > +} > + > +static int alloc_rx_slot(struct dln2_mod_rx_slots *rxs) > +{ > + int slot, ret; > + > + /* No need to timeout here, the wait is bounded by the timeout > + * in _dln2_transfer */ > + ret = wait_event_interruptible(rxs->wq, find_free_slot(rxs, &slot)); > + if (ret < 0) > + return ret; > + > + return slot; > +} > + > +static void free_rx_slot(struct dln2_dev *dln2, struct dln2_mod_rx_slots *rxs, > + int slot) > +{ > + struct urb *urb = NULL; > + unsigned long flags; > + struct dln2_rx_context *rxc; > + struct device *dev = &dln2->interface->dev; > + int ret; > + > + spin_lock_irqsave(&rxs->lock, flags); > + > + clear_bit(slot, &rxs->bmap); > + > + rxc = &rxs->slots[slot]; > + rxc->connected = false; > + urb = rxc->urb; > + rxc->urb = NULL; > + > + spin_unlock_irqrestore(&rxs->lock, flags); > + > + if (urb) { > + ret = usb_submit_urb(urb, GFP_KERNEL); > + if (ret < 0) > + dev_err(dev, "failed to re-submit RX URB: %d\n", ret); > + } > + > + wake_up_interruptible(&rxs->wq); > +} > + > +struct dln2_rx_cb_entry { > + struct list_head list; > + u16 id; > + struct platform_device *pdev; > + dln2_rx_cb_t callback; > +}; > + > +int dln2_register_event_cb(struct platform_device *pdev, u16 id, > + dln2_rx_cb_t rx_cb) > +{ > + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent); > + struct dln2_rx_cb_entry *i, *new; > + unsigned long flags; > + int ret = 0; > + > + new = kmalloc(sizeof(*new), GFP_KERNEL); > + if (!new) > + return -ENOMEM; > + > + new->id = id; > + new->callback = rx_cb; > + new->pdev = pdev; > + > + spin_lock_irqsave(&dln2->rx_cb_lock, flags); > + > + list_for_each_entry(i, &dln2->rx_cb_list, list) { > + if (i->id == id) { > + ret = -EBUSY; > + break; > + } > + } > + > + if (!ret) > + list_add(&new->list, &dln2->rx_cb_list); > + > + spin_unlock_irqrestore(&dln2->rx_cb_lock, flags); > + > + if (ret) > + kfree(new); > + > + return ret; > +} > +EXPORT_SYMBOL(dln2_register_event_cb); > + > +void dln2_unregister_event_cb(struct platform_device *pdev, u16 id) > +{ > + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent); > + struct dln2_rx_cb_entry *i, *tmp; > + unsigned long flags; > + > + spin_lock_irqsave(&dln2->rx_cb_lock, flags); > + > + list_for_each_entry_safe(i, tmp, &dln2->rx_cb_list, list) { > + if (i->id == id) { > + list_del(&i->list); > + kfree(i); > + } > + } > + > + spin_unlock_irqrestore(&dln2->rx_cb_lock, flags); > +} > +EXPORT_SYMBOL(dln2_unregister_event_cb); > + > +static void dln2_rx_transfer(struct dln2_dev *dln2, struct urb *urb, > + u16 handle, u16 rx_slot) > +{ > + struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle]; > + struct dln2_rx_context *rxc; > + struct device *dev = &dln2->interface->dev; > + int err; > + > + spin_lock(&rxs->lock); > + rxc = &rxs->slots[rx_slot]; > + if (rxc->connected) { > + rxc->urb = urb; > + complete(&rxc->done); > + } else { > + dev_warn(dev, "droping response %d/%d", handle, rx_slot); s/droping/dropping/ > + err = usb_submit_urb(urb, GFP_ATOMIC); > + if (err < 0) > + dev_err(dev, "failed to re-submit RX URB: %d\n", err); > + } > + spin_unlock(&rxs->lock); > +} > + > +static void dln2_run_rx_callbacks(struct dln2_dev *dln2, u16 id, u16 echo, > + void *data, int len) > +{ > + struct dln2_rx_cb_entry *i; > + > + spin_lock(&dln2->rx_cb_lock); > + > + list_for_each_entry(i, &dln2->rx_cb_list, list) > + if (i->id == id) > + i->callback(i->pdev, echo, data, len); > + > + spin_unlock(&dln2->rx_cb_lock); > +} > + > +static void dln2_rx(struct urb *urb) > +{ > + struct dln2_dev *dln2 = urb->context; > + struct dln2_header *hdr = urb->transfer_buffer; > + struct device *dev = &dln2->interface->dev; > + u16 id, echo, handle, size; > + u8 *data; > + int len, err; > + > + switch (urb->status) { > + case 0: > + /* success */ > + break; > + case -ECONNRESET: > + case -ENOENT: > + case -ESHUTDOWN: > + case -EPIPE: > + /* this urb is terminated, clean up */ > + dev_dbg(dev, "urb shutting down with status %d\n", urb->status); > + return; > + default: > + dev_dbg(dev, "nonzero urb status received %d\n", urb->status); > + goto out; > + } > + > + if (urb->actual_length < sizeof(struct dln2_header)) { > + dev_err(dev, "short response: %d\n", urb->actual_length); > + goto out; > + } > + > + handle = le16_to_cpu(hdr->handle); > + id = le16_to_cpu(hdr->id); > + echo = le16_to_cpu(hdr->echo); > + size = le16_to_cpu(hdr->size); > + > + if (size != urb->actual_length) { > + dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n", > + handle, id, echo, size, urb->actual_length); > + goto out; > + } > + > + if (handle > DLN2_MAX_MODULES) { You need (handle >= DLN2_MAX_MODULES) or you might end up with a buffer overflow in dln2_run_rx_callbacks. > + dev_warn(dev, "RX: invalid handle %d\n", handle); > + goto out; > + } > + > + data = urb->transfer_buffer + sizeof(struct dln2_header); > + len = urb->actual_length - sizeof(struct dln2_header); > + > + if (!handle) { Test if (handle == DLN2_HANDLE_EVENT) instead. > + dln2_run_rx_callbacks(dln2, id, echo, data, len); > + err = usb_submit_urb(urb, GFP_ATOMIC); > + if (err < 0) > + goto out_submit_failed; > + } else { > + dln2_rx_transfer(dln2, urb, handle, echo); > + } > + > + return; > + > +out: > + err = usb_submit_urb(urb, GFP_ATOMIC); > +out_submit_failed: > + if (err < 0) > + dev_err(dev, "failed to re-submit RX URB: %d\n", err); > +} > + > +static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, void *obuf, > + int *obuf_len, gfp_t gfp) > +{ > + void *buf; > + int len; > + struct dln2_header *hdr; > + > + len = *obuf_len + sizeof(*hdr); > + buf = kmalloc(len, gfp); > + if (!buf) > + return NULL; > + > + hdr = (struct dln2_header *)buf; > + hdr->id = cpu_to_le16(cmd); > + hdr->size = cpu_to_le16(len); > + hdr->echo = cpu_to_le16(echo); > + hdr->handle = cpu_to_le16(handle); > + > + memcpy(buf + sizeof(*hdr), obuf, *obuf_len); > + > + *obuf_len = len; > + > + return buf; > +} > + > +static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo, > + void *obuf, int obuf_len) > +{ > + int len = obuf_len, ret = 0, actual; > + void *buf; > + > + buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + ret = usb_bulk_msg(dln2->usb_dev, > + usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out), > + buf, len, &actual, DLN2_USB_TIMEOUT); > + > + kfree(buf); > + > + return ret; > +} > + > +static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd, > + void *obuf, int obuf_len, void *ibuf, int *ibuf_len) > +{ > + u16 result, rx_slot; > + struct dln2_response *rsp; > + int ret = 0; > + const int timeout = DLN2_USB_TIMEOUT * HZ / 1000; > + struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle]; > + struct dln2_rx_context *rxc; > + struct device *dev = &dln2->interface->dev; > + > + rx_slot = alloc_rx_slot(rxs); > + if (rx_slot < 0) > + return rx_slot; > + > + ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len); > + if (ret < 0) { > + free_rx_slot(dln2, rxs, rx_slot); > + dev_err(dev, "USB write failed: %d", ret); > + return ret; > + } > + > + rxc = &rxs->slots[rx_slot]; > + > + ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout); > + if (ret <= 0) { > + ret = !ret ? -ETIMEDOUT : ret; Don't use use ?: constructs. Setting ret to -ETIMEDOUT if 0 is much more readable. > + goto out_free_rx_slot; > + } > + > + /* if we got here we know that the response header has been checked */ > + rsp = rxc->urb->transfer_buffer; > + result = le16_to_cpu(rsp->result); Yes, but you haven't verified that rsp->hdr.size > 0, so you may still be reading stale data. > + > + if (result) { > + dev_dbg(dev, "%d received response with error %d\n", > + handle, result); > + ret = -EREMOTEIO; > + goto out_free_rx_slot; > + } > + > + if (!ibuf) { > + ret = 0; > + goto out_free_rx_slot; > + } > + > + if (*ibuf_len > rxc->urb->actual_length - sizeof(*rsp)) > + *ibuf_len = rxc->urb->actual_length - sizeof(*rsp); And then you get an underflow here, although that doesn't seem to cause any troubles in this case. But why isn't ibuf_len unsigned? > + > + memcpy(ibuf, rsp + 1, *ibuf_len); > + > +out_free_rx_slot: > + free_rx_slot(dln2, rxs, rx_slot); > + > + return ret; > +} > + > +struct dln2_platform_data { > + u16 handle; > +}; > + > +int dln2_transfer(struct platform_device *pdev, u16 cmd, > + void *obuf, int obuf_len, void *ibuf, int *ibuf_len) > +{ > + struct dln2_platform_data *dln2_pdata; > + struct dln2_dev *dln2; > + u16 h; > + > + /* USB device has been disconnected, bail out */ > + if (!pdev) > + return -ENODEV; > + > + dln2 = dev_get_drvdata(pdev->dev.parent); > + dln2_pdata = dev_get_platdata(&pdev->dev); > + h = dln2_pdata->handle; > + > + return _dln2_transfer(dln2, h, cmd, obuf, obuf_len, ibuf, ibuf_len); > +} > +EXPORT_SYMBOL(dln2_transfer); > + > +static int dln2_check_hw(struct dln2_dev *dln2) > +{ > + __le32 hw_type; > + int ret, len = sizeof(hw_type); Again, please use one declaration per line (and especially when initialising). > + > + ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER, > + NULL, 0, &hw_type, &len); > + if (ret < 0) > + return ret; > + You never check the returned buffer length. > + if (le32_to_cpu(hw_type) != DLN2_HW_ID) { > + dev_err(&dln2->interface->dev, "Device ID 0x%x not supported!", Exclamation mark really warranted? > + le32_to_cpu(hw_type)); > + return -ENODEV; > + } > + > + return 0; > +} > + > +static int dln2_print_serialno(struct dln2_dev *dln2) > +{ > + __le32 serial_no; > + int ret, len = sizeof(serial_no); > + struct device *dev = &dln2->interface->dev; > + > + ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0, > + &serial_no, &len); > + if (ret < 0) > + return ret; Verify buffer length. > + > + dev_info(dev, "Diolan DLN2 serial 0x%x\n", le32_to_cpu(serial_no)); > + > + return 0; > +} > + > +static int dln2_hw_init(struct dln2_dev *dln2) > +{ > + int ret = dln2_check_hw(dln2); Split declaration and non-trivial initialisation. > + > + if (ret < 0) > + return ret; > + > + return dln2_print_serialno(dln2); > +} > + > +static void dln2_free_rx_urbs(struct dln2_dev *dln2) > +{ > + int i; > + > + for (i = 0; i < DLN2_MAX_URBS; i++) { > + usb_kill_urb(dln2->rx_urb[i]); > + usb_free_urb(dln2->rx_urb[i]); > + kfree(dln2->rx_buf[i]); > + } > +} > + > +static void dln2_free(struct dln2_dev *dln2) > +{ > + dln2_free_rx_urbs(dln2); > + usb_put_dev(dln2->usb_dev); > + kfree(dln2); > +} > + > +static int dln2_setup_rx_urbs(struct dln2_dev *dln2, > + struct usb_host_interface *hostif) > +{ > + int i, ret; > + int rx_max_size = le16_to_cpu(hostif->endpoint[1].desc.wMaxPacketSize); > + struct device *dev = &dln2->interface->dev; > + > + for (i = 0; i < DLN2_MAX_URBS; i++) { > + dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL); > + if (!dln2->rx_buf[i]) > + return -ENOMEM; > + > + dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL); > + if (!dln2->rx_urb[i]) > + return -ENOMEM; > + > + usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev, > + usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in), > + dln2->rx_buf[i], rx_max_size, dln2_rx, dln2); > + > + ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL); > + if (ret < 0) { > + dev_err(dev, "failed to submit RX URB: %d\n", ret); > + return ret; > + } > + } > + > + return 0; > +} > + > +static struct dln2_platform_data dln2_pdata_gpio = { > + .handle = DLN2_HANDLE_GPIO, > +}; > + > +static struct dln2_platform_data dln2_pdata_i2c = { > + .handle = DLN2_HANDLE_I2C, > +}; > + > +static const struct mfd_cell dln2_devs[] = { > + { > + .name = "dln2-gpio", > + .platform_data = &dln2_pdata_gpio, > + .pdata_size = sizeof(struct dln2_platform_data), > + }, > + { > + .name = "dln2-i2c", > + .platform_data = &dln2_pdata_i2c, > + .pdata_size = sizeof(struct dln2_platform_data), > + }, > +}; > + > +static void dln2_disconnect(struct usb_interface *interface) > +{ > + struct dln2_dev *dln2 = usb_get_intfdata(interface); > + > + mfd_remove_devices(&interface->dev); > + dln2_free(dln2); > +} > + > +static int dln2_probe(struct usb_interface *interface, > + const struct usb_device_id *id) > +{ > + struct usb_host_interface *hostif = interface->cur_altsetting; > + struct device *dev = &interface->dev; > + struct dln2_dev *dln2; > + int ret, i; > + > + if (hostif->desc.bInterfaceNumber != 0 || > + hostif->desc.bNumEndpoints < 2) > + return -ENODEV; > + > + dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL); > + if (!dln2) { > + ret = -ENOMEM; > + goto out; Why not simply return -ENOMEM here as well? > + } > + > + dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress; > + dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress; > + dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface)); > + dln2->interface = interface; > + usb_set_intfdata(interface, dln2); > + > + for (i = 0; i < DLN2_MAX_MODULES; i++) { > + init_waitqueue_head(&dln2->mod_rx_slots[i].wq); > + spin_lock_init(&dln2->mod_rx_slots[i].lock); > + } > + > + spin_lock_init(&dln2->rx_cb_lock); > + INIT_LIST_HEAD(&dln2->rx_cb_list); > + > + ret = dln2_setup_rx_urbs(dln2, hostif); > + if (ret) { > + dln2_disconnect(interface); Call dln2_free directly here instead, and only let USB core use the USB callbacks directly (i.e. disconnect should only be called after a successful probe). > + return ret; > + } > + > + ret = dln2_hw_init(dln2); > + if (ret < 0) { > + dev_err(dev, "failed to initialize hardware\n"); > + goto out_cleanup; > + } > + > + ret = mfd_add_devices(dev, -1, dln2_devs, ARRAY_SIZE(dln2_devs), > + NULL, 0, NULL); > + if (ret != 0) { > + dev_err(dev, "Failed to add mfd devices to core.\n"); > + goto out_cleanup; > + } > + > + return 0; > + > +out_cleanup: > + dln2_free(dln2); > +out: > + return ret; > +} > + > +static const struct usb_device_id dln2_table[] = { > + { USB_DEVICE(0xa257, 0x2013) }, > + { } > +}; > + > +MODULE_DEVICE_TABLE(usb, dln2_table); > + > +static struct usb_driver dln2_driver = { > + .name = DRIVER_NAME, > + .probe = dln2_probe, > + .disconnect = dln2_disconnect, > + .id_table = dln2_table, > +}; > + > +module_usb_driver(dln2_driver); > + > +MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>"); > +MODULE_DESCRIPTION(DRIVER_NAME " driver"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/mfd/dln2.h b/include/linux/mfd/dln2.h > new file mode 100644 > index 0000000..731bf32 > --- /dev/null > +++ b/include/linux/mfd/dln2.h > @@ -0,0 +1,61 @@ > +#ifndef __LINUX_USB_DLN2_H > +#define __LINUX_USB_DLN2_H > + > +#define DLN2_CMD(cmd, id) ((cmd) | ((id) << 8)) > + > +/** > + * dln2_rx_cb - event callback function signature > + * > + * @pdev - the sub-device that registered this callback > + * @echo - the echo header field received in the message > + * @data - the data payload > + * @len - the data playload length s/playload/payload/ > + * > + * The callback function is called in interrupt context and the data > + * payload is only valid during the call. If the user needs later > + * access of the data, it must copy it. > + */ > + > +typedef void (*dln2_rx_cb_t)(struct platform_device *pdev, u16 echo, > + const void *data, int len); > + > +/** > + * dl2n_register_event_cb - register a callback function for an event > + * > + * @pdev - the sub-device that registers the callback > + * @event - the event for which to register a callback > + * @rx_cb - the callback function > + * > + * @return 0 in case of success, negative value in case of error > + */ > +int dln2_register_event_cb(struct platform_device *pdev, u16 event, > + dln2_rx_cb_t rx_cb); > + > +/** > + * dln2_unregister_event_cb - unregister the callback function for an event > + * > + * @pdev - the sub-device that registered the callback > + * @event - the event for which to register a callback > + */ > +void dln2_unregister_event_cb(struct platform_device *pdev, u16 event); > + > +/** > + * dln2_transfer - issue a DLN2 command and wait for a response and > + * the associated data > + * > + * @pdev - the sub-device which is issueing this transfer s/issueing/issuing/ > + * @cmd - the command to be sent to the device > + * @obuf - the buffer to be sent to the device; can be NULL if the > + * user doesn't need to transmit data with this command > + * @obuf_len - the size of the buffer to be sent to the device > + * @ibuf - any data associated with the response will be copied here; > + * it can be NULL if the user doesn't need the response data > + * @ibuf_len - must be initialized to the input buffer size; it will > + * be modified to indicate the actual data transfered > + * > + * @returns 0 for success, negative value for errors > + */ > +int dln2_transfer(struct platform_device *pdev, u16 cmd, > + void *obuf, int obuf_len, void *ibuf, int *ibuf_len); > + > +#endif Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 08, 2014 at 01:32:33PM +0200, Johan Hovold wrote: > On Fri, Sep 05, 2014 at 06:17:57PM +0300, Octavian Purdila wrote: > > +static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd, > > + void *obuf, int obuf_len, void *ibuf, int *ibuf_len) > > +{ <snip> > > + /* if we got here we know that the response header has been checked */ > > + rsp = rxc->urb->transfer_buffer; > > + result = le16_to_cpu(rsp->result); > > Yes, but you haven't verified that rsp->hdr.size > 0, so you may still > be reading stale data. I meant that you haven't verified that the payload size > 1 (the header size is included in rsp->hdr.size and result is two byte wide). > > + > > + if (result) { > > + dev_dbg(dev, "%d received response with error %d\n", > > + handle, result); > > + ret = -EREMOTEIO; > > + goto out_free_rx_slot; > > + } > > + > > + if (!ibuf) { > > + ret = 0; > > + goto out_free_rx_slot; > > + } > > + > > + if (*ibuf_len > rxc->urb->actual_length - sizeof(*rsp)) > > + *ibuf_len = rxc->urb->actual_length - sizeof(*rsp); > > And then you get an underflow here, although that doesn't seem to cause > any troubles in this case. Unless ibuf_len is -1... > But why isn't ibuf_len unsigned? > > > + > > + memcpy(ibuf, rsp + 1, *ibuf_len); > > + > > +out_free_rx_slot: > > + free_rx_slot(dln2, rxs, rx_slot); > > + > > + return ret; > > +} Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 8, 2014 at 2:32 PM, Johan Hovold <johan@kernel.org> wrote: > > On Fri, Sep 05, 2014 at 06:17:57PM +0300, Octavian Purdila wrote: > > This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO > > Master Adapter DLN-2. Details about the device can be found here: > > <snip> > > First of all, this is much cleaner than the first non-MFD version. I'll > have a look at the subdrivers shortly as well. > Hi Johan, I have addressed all you comments except one, please see bellow. I will wait for the review on the subdrivers before submitting a new version of the patch set. Thanks for for review ! <snip> > > +static bool find_free_slot(struct dln2_mod_rx_slots *rxs, int *slot) > > +{ > > + unsigned long flags; > > + > > + spin_lock_irqsave(&rxs->lock, flags); > > + > > + *slot = find_first_zero_bit(&rxs->bmap, DLN2_MAX_RX_SLOTS); > > + > > + if (*slot < DLN2_MAX_RX_SLOTS) { > > + struct dln2_rx_context *rxc = &rxs->slots[*slot]; > > + > > + init_completion(&rxc->done); > > Initialise the completions when you allocate them (and there's no need > to re-init here). > You are right, but I think we need a reinit_completion(). Technically we don't, as we don't use complete_all(), but I feel it is cleaner that way. I will move the initialization in probe and add the reinit_completion() in free_rx_slot. Is that OK with you? -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 08 Sep 2014, Octavian Purdila wrote: > On Mon, Sep 8, 2014 at 2:32 PM, Johan Hovold <johan@kernel.org> wrote: > > > > On Fri, Sep 05, 2014 at 06:17:57PM +0300, Octavian Purdila wrote: > > > This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO > > > Master Adapter DLN-2. Details about the device can be found here: > > > > <snip> > > > > First of all, this is much cleaner than the first non-MFD version. I'll > > have a look at the subdrivers shortly as well. > > > > Hi Johan, > > I have addressed all you comments except one, please see bellow. I > will wait for the review on the subdrivers before submitting a new > version of the patch set. Thanks for for review ! No, please don't. Fix-up and resubmit.
On Mon, Sep 08, 2014 at 04:20:34PM +0300, Octavian Purdila wrote: > On Mon, Sep 8, 2014 at 2:32 PM, Johan Hovold <johan@kernel.org> wrote: > > > +static bool find_free_slot(struct dln2_mod_rx_slots *rxs, int *slot) > > > +{ > > > + unsigned long flags; > > > + > > > + spin_lock_irqsave(&rxs->lock, flags); > > > + > > > + *slot = find_first_zero_bit(&rxs->bmap, DLN2_MAX_RX_SLOTS); > > > + > > > + if (*slot < DLN2_MAX_RX_SLOTS) { > > > + struct dln2_rx_context *rxc = &rxs->slots[*slot]; > > > + > > > + init_completion(&rxc->done); > > > > Initialise the completions when you allocate them (and there's no need > > to re-init here). > > You are right, but I think we need a reinit_completion(). Technically > we don't, as we don't use complete_all(), but I feel it is cleaner > that way. I will move the initialization in probe and add the > reinit_completion() in free_rx_slot. Is that OK with you? Sure, that's fine. Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index de5abf2..7bcf895 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -183,6 +183,15 @@ config MFD_DA9063 Additional drivers must be enabled in order to use the functionality of the device. +config MFD_DLN2 + tristate "Diolan DLN2 support" + select MFD_CORE + depends on USB + help + This adds support for Diolan USB-I2C/SPI/GPIO Master Adapter DLN-2. + Additional drivers must be enabled in order to use the functionality + of the device. + config MFD_MC13XXX tristate depends on (SPI_MASTER || I2C) diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index f001487..591988d 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711) += as3711.o obj-$(CONFIG_MFD_AS3722) += as3722.o obj-$(CONFIG_MFD_STW481X) += stw481x.o obj-$(CONFIG_MFD_IPAQ_MICRO) += ipaq-micro.o +obj-$(CONFIG_MFD_DLN2) += dln2.o intel-soc-pmic-objs := intel_soc_pmic_core.o intel_soc_pmic_crc.o obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c new file mode 100644 index 0000000..81ff58e --- /dev/null +++ b/drivers/mfd/dln2.c @@ -0,0 +1,653 @@ +/* + * Driver for the Diolan DLN-2 USB adapter + * + * Copyright (c) 2014 Intel Corporation + * + * Derived from: + * i2c-diolan-u2c.c + * Copyright (c) 2010-2011 Ericsson AB + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2. + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/usb.h> +#include <linux/i2c.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/mfd/core.h> +#include <linux/mfd/dln2.h> + +#define DRIVER_NAME "usb-dln2" + +struct dln2_header { + __le16 size; + __le16 id; + __le16 echo; + __le16 handle; +} __packed; + +struct dln2_response { + struct dln2_header hdr; + __le16 result; +} __packed; + +#define DLN2_GENERIC_MODULE_ID 0x00 +#define DLN2_GENERIC_CMD(cmd) DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID) +#define CMD_GET_DEVICE_VER DLN2_GENERIC_CMD(0x30) +#define CMD_GET_DEVICE_SN DLN2_GENERIC_CMD(0x31) + +#define DLN2_HW_ID 0x200 +#define DLN2_USB_TIMEOUT 200 /* in ms */ +#define DLN2_MAX_RX_SLOTS 16 +#define DLN2_MAX_MODULES 5 +#define DLN2_MAX_URBS 16 + +#define DLN2_HANDLE_GPIO_EVENT 0 +#define DLN2_HANDLE_CTRL 1 +#define DLN2_HANDLE_GPIO 2 +#define DLN2_HANDLE_I2C 3 + +/* Receive context used between the receive demultiplexer and the + * transfer routine. While sending a request the transfer routine + * will look for a free receive context and use it to wait for a + * response and to receive the URB and thus the response data. */ +struct dln2_rx_context { + struct completion done; + struct urb *urb; + bool connected; +}; + +/* Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We + * use the handle header field to indentify the module in + * dln2_dev.mod_rx_slots and then the echo header field to index the + * slots field and find the receive context for a particular + * request. */ +struct dln2_mod_rx_slots { + /* RX slots bitmap */ + unsigned long bmap; + + /* used to wait for a free RX slot */ + wait_queue_head_t wq; + + /* used to wait for an RX operation to complete */ + struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS]; + + /* avoid races between free_rx_slot and dln2_rx_transfer_cb */ + spinlock_t lock; +}; + +struct dln2_dev { + struct usb_device *usb_dev; + struct usb_interface *interface; + u8 ep_in; + u8 ep_out; + + struct urb *rx_urb[DLN2_MAX_URBS]; + void *rx_buf[DLN2_MAX_URBS]; + + struct dln2_mod_rx_slots mod_rx_slots[DLN2_MAX_MODULES]; + + struct list_head rx_cb_list; + spinlock_t rx_cb_lock; +}; + +static bool find_free_slot(struct dln2_mod_rx_slots *rxs, int *slot) +{ + unsigned long flags; + + spin_lock_irqsave(&rxs->lock, flags); + + *slot = find_first_zero_bit(&rxs->bmap, DLN2_MAX_RX_SLOTS); + + if (*slot < DLN2_MAX_RX_SLOTS) { + struct dln2_rx_context *rxc = &rxs->slots[*slot]; + + init_completion(&rxc->done); + set_bit(*slot, &rxs->bmap); + rxc->connected = true; + } + + spin_unlock_irqrestore(&rxs->lock, flags); + + return *slot < DLN2_MAX_RX_SLOTS; +} + +static int alloc_rx_slot(struct dln2_mod_rx_slots *rxs) +{ + int slot, ret; + + /* No need to timeout here, the wait is bounded by the timeout + * in _dln2_transfer */ + ret = wait_event_interruptible(rxs->wq, find_free_slot(rxs, &slot)); + if (ret < 0) + return ret; + + return slot; +} + +static void free_rx_slot(struct dln2_dev *dln2, struct dln2_mod_rx_slots *rxs, + int slot) +{ + struct urb *urb = NULL; + unsigned long flags; + struct dln2_rx_context *rxc; + struct device *dev = &dln2->interface->dev; + int ret; + + spin_lock_irqsave(&rxs->lock, flags); + + clear_bit(slot, &rxs->bmap); + + rxc = &rxs->slots[slot]; + rxc->connected = false; + urb = rxc->urb; + rxc->urb = NULL; + + spin_unlock_irqrestore(&rxs->lock, flags); + + if (urb) { + ret = usb_submit_urb(urb, GFP_KERNEL); + if (ret < 0) + dev_err(dev, "failed to re-submit RX URB: %d\n", ret); + } + + wake_up_interruptible(&rxs->wq); +} + +struct dln2_rx_cb_entry { + struct list_head list; + u16 id; + struct platform_device *pdev; + dln2_rx_cb_t callback; +}; + +int dln2_register_event_cb(struct platform_device *pdev, u16 id, + dln2_rx_cb_t rx_cb) +{ + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent); + struct dln2_rx_cb_entry *i, *new; + unsigned long flags; + int ret = 0; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return -ENOMEM; + + new->id = id; + new->callback = rx_cb; + new->pdev = pdev; + + spin_lock_irqsave(&dln2->rx_cb_lock, flags); + + list_for_each_entry(i, &dln2->rx_cb_list, list) { + if (i->id == id) { + ret = -EBUSY; + break; + } + } + + if (!ret) + list_add(&new->list, &dln2->rx_cb_list); + + spin_unlock_irqrestore(&dln2->rx_cb_lock, flags); + + if (ret) + kfree(new); + + return ret; +} +EXPORT_SYMBOL(dln2_register_event_cb); + +void dln2_unregister_event_cb(struct platform_device *pdev, u16 id) +{ + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent); + struct dln2_rx_cb_entry *i, *tmp; + unsigned long flags; + + spin_lock_irqsave(&dln2->rx_cb_lock, flags); + + list_for_each_entry_safe(i, tmp, &dln2->rx_cb_list, list) { + if (i->id == id) { + list_del(&i->list); + kfree(i); + } + } + + spin_unlock_irqrestore(&dln2->rx_cb_lock, flags); +} +EXPORT_SYMBOL(dln2_unregister_event_cb); + +static void dln2_rx_transfer(struct dln2_dev *dln2, struct urb *urb, + u16 handle, u16 rx_slot) +{ + struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle]; + struct dln2_rx_context *rxc; + struct device *dev = &dln2->interface->dev; + int err; + + spin_lock(&rxs->lock); + rxc = &rxs->slots[rx_slot]; + if (rxc->connected) { + rxc->urb = urb; + complete(&rxc->done); + } else { + dev_warn(dev, "droping response %d/%d", handle, rx_slot); + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err < 0) + dev_err(dev, "failed to re-submit RX URB: %d\n", err); + } + spin_unlock(&rxs->lock); +} + +static void dln2_run_rx_callbacks(struct dln2_dev *dln2, u16 id, u16 echo, + void *data, int len) +{ + struct dln2_rx_cb_entry *i; + + spin_lock(&dln2->rx_cb_lock); + + list_for_each_entry(i, &dln2->rx_cb_list, list) + if (i->id == id) + i->callback(i->pdev, echo, data, len); + + spin_unlock(&dln2->rx_cb_lock); +} + +static void dln2_rx(struct urb *urb) +{ + struct dln2_dev *dln2 = urb->context; + struct dln2_header *hdr = urb->transfer_buffer; + struct device *dev = &dln2->interface->dev; + u16 id, echo, handle, size; + u8 *data; + int len, err; + + switch (urb->status) { + case 0: + /* success */ + break; + case -ECONNRESET: + case -ENOENT: + case -ESHUTDOWN: + case -EPIPE: + /* this urb is terminated, clean up */ + dev_dbg(dev, "urb shutting down with status %d\n", urb->status); + return; + default: + dev_dbg(dev, "nonzero urb status received %d\n", urb->status); + goto out; + } + + if (urb->actual_length < sizeof(struct dln2_header)) { + dev_err(dev, "short response: %d\n", urb->actual_length); + goto out; + } + + handle = le16_to_cpu(hdr->handle); + id = le16_to_cpu(hdr->id); + echo = le16_to_cpu(hdr->echo); + size = le16_to_cpu(hdr->size); + + if (size != urb->actual_length) { + dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n", + handle, id, echo, size, urb->actual_length); + goto out; + } + + if (handle > DLN2_MAX_MODULES) { + dev_warn(dev, "RX: invalid handle %d\n", handle); + goto out; + } + + data = urb->transfer_buffer + sizeof(struct dln2_header); + len = urb->actual_length - sizeof(struct dln2_header); + + if (!handle) { + dln2_run_rx_callbacks(dln2, id, echo, data, len); + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err < 0) + goto out_submit_failed; + } else { + dln2_rx_transfer(dln2, urb, handle, echo); + } + + return; + +out: + err = usb_submit_urb(urb, GFP_ATOMIC); +out_submit_failed: + if (err < 0) + dev_err(dev, "failed to re-submit RX URB: %d\n", err); +} + +static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, void *obuf, + int *obuf_len, gfp_t gfp) +{ + void *buf; + int len; + struct dln2_header *hdr; + + len = *obuf_len + sizeof(*hdr); + buf = kmalloc(len, gfp); + if (!buf) + return NULL; + + hdr = (struct dln2_header *)buf; + hdr->id = cpu_to_le16(cmd); + hdr->size = cpu_to_le16(len); + hdr->echo = cpu_to_le16(echo); + hdr->handle = cpu_to_le16(handle); + + memcpy(buf + sizeof(*hdr), obuf, *obuf_len); + + *obuf_len = len; + + return buf; +} + +static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo, + void *obuf, int obuf_len) +{ + int len = obuf_len, ret = 0, actual; + void *buf; + + buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ret = usb_bulk_msg(dln2->usb_dev, + usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out), + buf, len, &actual, DLN2_USB_TIMEOUT); + + kfree(buf); + + return ret; +} + +static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd, + void *obuf, int obuf_len, void *ibuf, int *ibuf_len) +{ + u16 result, rx_slot; + struct dln2_response *rsp; + int ret = 0; + const int timeout = DLN2_USB_TIMEOUT * HZ / 1000; + struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle]; + struct dln2_rx_context *rxc; + struct device *dev = &dln2->interface->dev; + + rx_slot = alloc_rx_slot(rxs); + if (rx_slot < 0) + return rx_slot; + + ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len); + if (ret < 0) { + free_rx_slot(dln2, rxs, rx_slot); + dev_err(dev, "USB write failed: %d", ret); + return ret; + } + + rxc = &rxs->slots[rx_slot]; + + ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout); + if (ret <= 0) { + ret = !ret ? -ETIMEDOUT : ret; + goto out_free_rx_slot; + } + + /* if we got here we know that the response header has been checked */ + rsp = rxc->urb->transfer_buffer; + result = le16_to_cpu(rsp->result); + + if (result) { + dev_dbg(dev, "%d received response with error %d\n", + handle, result); + ret = -EREMOTEIO; + goto out_free_rx_slot; + } + + if (!ibuf) { + ret = 0; + goto out_free_rx_slot; + } + + if (*ibuf_len > rxc->urb->actual_length - sizeof(*rsp)) + *ibuf_len = rxc->urb->actual_length - sizeof(*rsp); + + memcpy(ibuf, rsp + 1, *ibuf_len); + +out_free_rx_slot: + free_rx_slot(dln2, rxs, rx_slot); + + return ret; +} + +struct dln2_platform_data { + u16 handle; +}; + +int dln2_transfer(struct platform_device *pdev, u16 cmd, + void *obuf, int obuf_len, void *ibuf, int *ibuf_len) +{ + struct dln2_platform_data *dln2_pdata; + struct dln2_dev *dln2; + u16 h; + + /* USB device has been disconnected, bail out */ + if (!pdev) + return -ENODEV; + + dln2 = dev_get_drvdata(pdev->dev.parent); + dln2_pdata = dev_get_platdata(&pdev->dev); + h = dln2_pdata->handle; + + return _dln2_transfer(dln2, h, cmd, obuf, obuf_len, ibuf, ibuf_len); +} +EXPORT_SYMBOL(dln2_transfer); + +static int dln2_check_hw(struct dln2_dev *dln2) +{ + __le32 hw_type; + int ret, len = sizeof(hw_type); + + ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER, + NULL, 0, &hw_type, &len); + if (ret < 0) + return ret; + + if (le32_to_cpu(hw_type) != DLN2_HW_ID) { + dev_err(&dln2->interface->dev, "Device ID 0x%x not supported!", + le32_to_cpu(hw_type)); + return -ENODEV; + } + + return 0; +} + +static int dln2_print_serialno(struct dln2_dev *dln2) +{ + __le32 serial_no; + int ret, len = sizeof(serial_no); + struct device *dev = &dln2->interface->dev; + + ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0, + &serial_no, &len); + if (ret < 0) + return ret; + + dev_info(dev, "Diolan DLN2 serial 0x%x\n", le32_to_cpu(serial_no)); + + return 0; +} + +static int dln2_hw_init(struct dln2_dev *dln2) +{ + int ret = dln2_check_hw(dln2); + + if (ret < 0) + return ret; + + return dln2_print_serialno(dln2); +} + +static void dln2_free_rx_urbs(struct dln2_dev *dln2) +{ + int i; + + for (i = 0; i < DLN2_MAX_URBS; i++) { + usb_kill_urb(dln2->rx_urb[i]); + usb_free_urb(dln2->rx_urb[i]); + kfree(dln2->rx_buf[i]); + } +} + +static void dln2_free(struct dln2_dev *dln2) +{ + dln2_free_rx_urbs(dln2); + usb_put_dev(dln2->usb_dev); + kfree(dln2); +} + +static int dln2_setup_rx_urbs(struct dln2_dev *dln2, + struct usb_host_interface *hostif) +{ + int i, ret; + int rx_max_size = le16_to_cpu(hostif->endpoint[1].desc.wMaxPacketSize); + struct device *dev = &dln2->interface->dev; + + for (i = 0; i < DLN2_MAX_URBS; i++) { + dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL); + if (!dln2->rx_buf[i]) + return -ENOMEM; + + dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL); + if (!dln2->rx_urb[i]) + return -ENOMEM; + + usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev, + usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in), + dln2->rx_buf[i], rx_max_size, dln2_rx, dln2); + + ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL); + if (ret < 0) { + dev_err(dev, "failed to submit RX URB: %d\n", ret); + return ret; + } + } + + return 0; +} + +static struct dln2_platform_data dln2_pdata_gpio = { + .handle = DLN2_HANDLE_GPIO, +}; + +static struct dln2_platform_data dln2_pdata_i2c = { + .handle = DLN2_HANDLE_I2C, +}; + +static const struct mfd_cell dln2_devs[] = { + { + .name = "dln2-gpio", + .platform_data = &dln2_pdata_gpio, + .pdata_size = sizeof(struct dln2_platform_data), + }, + { + .name = "dln2-i2c", + .platform_data = &dln2_pdata_i2c, + .pdata_size = sizeof(struct dln2_platform_data), + }, +}; + +static void dln2_disconnect(struct usb_interface *interface) +{ + struct dln2_dev *dln2 = usb_get_intfdata(interface); + + mfd_remove_devices(&interface->dev); + dln2_free(dln2); +} + +static int dln2_probe(struct usb_interface *interface, + const struct usb_device_id *id) +{ + struct usb_host_interface *hostif = interface->cur_altsetting; + struct device *dev = &interface->dev; + struct dln2_dev *dln2; + int ret, i; + + if (hostif->desc.bInterfaceNumber != 0 || + hostif->desc.bNumEndpoints < 2) + return -ENODEV; + + dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL); + if (!dln2) { + ret = -ENOMEM; + goto out; + } + + dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress; + dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress; + dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface)); + dln2->interface = interface; + usb_set_intfdata(interface, dln2); + + for (i = 0; i < DLN2_MAX_MODULES; i++) { + init_waitqueue_head(&dln2->mod_rx_slots[i].wq); + spin_lock_init(&dln2->mod_rx_slots[i].lock); + } + + spin_lock_init(&dln2->rx_cb_lock); + INIT_LIST_HEAD(&dln2->rx_cb_list); + + ret = dln2_setup_rx_urbs(dln2, hostif); + if (ret) { + dln2_disconnect(interface); + return ret; + } + + ret = dln2_hw_init(dln2); + if (ret < 0) { + dev_err(dev, "failed to initialize hardware\n"); + goto out_cleanup; + } + + ret = mfd_add_devices(dev, -1, dln2_devs, ARRAY_SIZE(dln2_devs), + NULL, 0, NULL); + if (ret != 0) { + dev_err(dev, "Failed to add mfd devices to core.\n"); + goto out_cleanup; + } + + return 0; + +out_cleanup: + dln2_free(dln2); +out: + return ret; +} + +static const struct usb_device_id dln2_table[] = { + { USB_DEVICE(0xa257, 0x2013) }, + { } +}; + +MODULE_DEVICE_TABLE(usb, dln2_table); + +static struct usb_driver dln2_driver = { + .name = DRIVER_NAME, + .probe = dln2_probe, + .disconnect = dln2_disconnect, + .id_table = dln2_table, +}; + +module_usb_driver(dln2_driver); + +MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>"); +MODULE_DESCRIPTION(DRIVER_NAME " driver"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mfd/dln2.h b/include/linux/mfd/dln2.h new file mode 100644 index 0000000..731bf32 --- /dev/null +++ b/include/linux/mfd/dln2.h @@ -0,0 +1,61 @@ +#ifndef __LINUX_USB_DLN2_H +#define __LINUX_USB_DLN2_H + +#define DLN2_CMD(cmd, id) ((cmd) | ((id) << 8)) + +/** + * dln2_rx_cb - event callback function signature + * + * @pdev - the sub-device that registered this callback + * @echo - the echo header field received in the message + * @data - the data payload + * @len - the data playload length + * + * The callback function is called in interrupt context and the data + * payload is only valid during the call. If the user needs later + * access of the data, it must copy it. + */ + +typedef void (*dln2_rx_cb_t)(struct platform_device *pdev, u16 echo, + const void *data, int len); + +/** + * dl2n_register_event_cb - register a callback function for an event + * + * @pdev - the sub-device that registers the callback + * @event - the event for which to register a callback + * @rx_cb - the callback function + * + * @return 0 in case of success, negative value in case of error + */ +int dln2_register_event_cb(struct platform_device *pdev, u16 event, + dln2_rx_cb_t rx_cb); + +/** + * dln2_unregister_event_cb - unregister the callback function for an event + * + * @pdev - the sub-device that registered the callback + * @event - the event for which to register a callback + */ +void dln2_unregister_event_cb(struct platform_device *pdev, u16 event); + +/** + * dln2_transfer - issue a DLN2 command and wait for a response and + * the associated data + * + * @pdev - the sub-device which is issueing this transfer + * @cmd - the command to be sent to the device + * @obuf - the buffer to be sent to the device; can be NULL if the + * user doesn't need to transmit data with this command + * @obuf_len - the size of the buffer to be sent to the device + * @ibuf - any data associated with the response will be copied here; + * it can be NULL if the user doesn't need the response data + * @ibuf_len - must be initialized to the input buffer size; it will + * be modified to indicate the actual data transfered + * + * @returns 0 for success, negative value for errors + */ +int dln2_transfer(struct platform_device *pdev, u16 cmd, + void *obuf, int obuf_len, void *ibuf, int *ibuf_len); + +#endif
This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO Master Adapter DLN-2. Details about the device can be found here: https://www.diolan.com/i2c/i2c_interface.html. Information about the USB protocol can be found in the Programmer's Reference Manual [1], see section 1.7. Because the hardware has a single transmit endpoint and a single receive endpoint the communication between the various DLN2 drivers and the hardware will be muxed/demuxed by this driver. Each DLN2 module will be identified by the handle field within the DLN2 message header. If a DLN2 module issues multiple commands in parallel they will be identified by the echo counter field in the message header. The DLN2 modules can use the dln2_transfer() function to issue a command and wait for its response. They can also register a callback that is going to be called when a specific event id is generated by the device (e.g. GPIO interrupts). The device uses handle 0 for sending events. [1] https://www.diolan.com/downloads/dln-api-manual.pdf Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> --- drivers/mfd/Kconfig | 9 + drivers/mfd/Makefile | 1 + drivers/mfd/dln2.c | 653 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/dln2.h | 61 +++++ 4 files changed, 724 insertions(+) create mode 100644 drivers/mfd/dln2.c create mode 100644 include/linux/mfd/dln2.h