Re: [PATCH v8 1/4] mfd: add support for Diolan DLN-2 devices
On Mon, Oct 27, 2014 at 03:21:10PM +0200, Octavian Purdila wrote:
> On Thu, Oct 23, 2014 at 6:16 PM, Johan Hovold wrote:
> > On Wed, Oct 15, 2014 at 05:48:08PM +0300, Octavian Purdila wrote:
> > > +struct dln2_event_cb_entry {
> > > + struct list_head list;
> > > + u16 id;
> > > + struct platform_device *pdev;
> > > + dln2_event_cb_t callback;
> > > +};
> > > +
> > > +int dln2_register_event_cb(struct platform_device *pdev, u16 id,
> > > +dln2_event_cb_t rx_cb)
> > > +{
> > > + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
> > > + struct dln2_event_cb_entry *i, *new_cb;
> >
> > Can you use a name which does not have the same suffix as the actual
> > callback function (i.e. "_cb"). Just call it "entry" or something.
> >
>
> OK.
>
> > > + unsigned long flags;
> > > + int ret = 0;
> > > +
> > > + new_cb = kmalloc(sizeof(*new_cb), GFP_KERNEL);
> >
> > Use kzalloc here.
>
> Why kzalloc? All of the fields are initialized below.
It's good practise to clear any data structure at allocation. The cost
is negligible.
> > > + if (!new_cb)
> > > + return -ENOMEM;
> > > +
> > > + new_cb->id = id;
> > > + new_cb->callback = rx_cb;
> > > + new_cb->pdev = pdev;
> > > +
> > > + spin_lock_irqsave(&dln2->event_cb_lock, flags);
> > > +
> > > + list_for_each_entry(i, &dln2->event_cb_list, list) {
> > > + if (i->id == id) {
> > > + ret = -EBUSY;
> > > + break;
> > > + }
> > > + }
> > > +
> > > + if (!ret)
> > > + list_add_rcu(&new_cb->list, &dln2->event_cb_list);
> > > +
> > > + spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
> > > +
> > > + if (ret)
> > > + kfree(new_cb);
> > > +
> > > + return ret;
> > > +}
> > > +EXPORT_SYMBOL(dln2_register_event_cb);
> > > + ret = mfd_add_hotplug_devices(dev, dln2_devs,
> > > ARRAY_SIZE(dln2_devs));
> >
> > So this now depends on 15bb4d6e8534 ("mfd: core: Add helper function to
> > register hotplug devices") in the MFD tree.
> >
> > Please mention what tree the patch is against in your cover letter (I
> > noticed you had rebased when it no longer applied to 3.17).
> >
> > You should drop the gpiolib patch now that v3.18-rc1 is out as well.
>
> This series is based against the Lee's for-mfd-next-v3.19 tree that
> does not yet contain the gpiolib patch.
Ok, but make sure to include that information in the cover letter.
Johan
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Re: [PATCH v8 1/4] mfd: add support for Diolan DLN-2 devices
On Thu, Oct 23, 2014 at 6:16 PM, Johan Hovold wrote:
>
> On Wed, Oct 15, 2014 at 05:48:08PM +0300, Octavian Purdila wrote:
>
> Here's some late feedback due to travels. You managed to get two updates
> in there so commenting on the diff from v6.
>
Thanks for the review :)
> > +struct dln2_event_cb_entry {
> > + struct list_head list;
> > + u16 id;
> > + struct platform_device *pdev;
> > + dln2_event_cb_t callback;
> > +};
> > +
> > +int dln2_register_event_cb(struct platform_device *pdev, u16 id,
> > +dln2_event_cb_t rx_cb)
> > +{
> > + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
> > + struct dln2_event_cb_entry *i, *new_cb;
>
> Can you use a name which does not have the same suffix as the actual
> callback function (i.e. "_cb"). Just call it "entry" or something.
>
OK.
> > + unsigned long flags;
> > + int ret = 0;
> > +
> > + new_cb = kmalloc(sizeof(*new_cb), GFP_KERNEL);
>
> Use kzalloc here.
Why kzalloc? All of the fields are initialized below.
>
> > + if (!new_cb)
> > + return -ENOMEM;
> > +
> > + new_cb->id = id;
> > + new_cb->callback = rx_cb;
> > + new_cb->pdev = pdev;
> > +
> > + spin_lock_irqsave(&dln2->event_cb_lock, flags);
> > +
> > + list_for_each_entry(i, &dln2->event_cb_list, list) {
> > + if (i->id == id) {
> > + ret = -EBUSY;
> > + break;
> > + }
> > + }
> > +
> > + if (!ret)
> > + list_add_rcu(&new_cb->list, &dln2->event_cb_list);
> > +
> > + spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
> > +
> > + if (ret)
> > + kfree(new_cb);
> > +
> > + 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_event_cb_entry *i;
> > + unsigned long flags;
> > + bool found = false;
> > +
> > + spin_lock_irqsave(&dln2->event_cb_lock, flags);
> > +
> > + list_for_each_entry(i, &dln2->event_cb_list, list) {
> > + if (i->id == id) {
> > + list_del_rcu(&i->list);
> > + found = true;
> > + break;
> > + }
> > + }
> > +
> > + spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
> > +
> > + if (found) {
> > + synchronize_rcu();
> > + kfree(i);
> > + }
> > +}
> > +EXPORT_SYMBOL(dln2_unregister_event_cb);
> > +
>
> Please add a comment describing the return value (i.e. when the urb had
> been saved and shouldn't be resubmitted).
>
> Also could rename this helper so it doesn't appear to be a variant of
> dln2_transfer (e.g. something with "complete" in the name).
>
Ok, I will use dln2_transfer_complete.
> > +static bool 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;
> > + bool ret = false;
> > +
> > + rxc = &rxs->slots[rx_slot];
> > +
> > + /*
> > + * No need to disable interrupts as this lock is not taken in
> > + * interrupt context elsewhere in this driver and this
> > + * function (or its callers) are not exported to other
> > + * modules.
>
> Why do you break comment lines already at 70 chars?
>
Oops, relic in my .emacs, will fix all comments in v9.
> > + */
> > + spin_lock(&rxs->lock);
> > + if (rxc->in_use && !rxc->urb) {
> > + rxc->urb = urb;
> > + complete(&rxc->done);
> > + ret = true;
> > + }
> > + spin_unlock(&rxs->lock);
> > +
> > + return ret;
> > +}
> > +
> > +static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16
> > echo,
> > + void *data, int len)
> > +{
> > + struct dln2_event_cb_entry *i;
> > +
> > + rcu_read_lock();
> > +
> > + list_for_each_entry_rcu(i, &dln2->event_cb_list, list)
> > + if (i->id == id)
> > + i->callback(i->pdev, echo, data, len);
> > +
> > + rcu_read_unlock();
> > +}
> > +
> > +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;
> > + int 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;
> > +
Re: [PATCH v8 1/4] mfd: add support for Diolan DLN-2 devices
On Wed, Oct 15, 2014 at 05:48:08PM +0300, Octavian Purdila wrote:
Here's some late feedback due to travels. You managed to get two updates
in there so commenting on the diff from v6.
> +struct dln2_event_cb_entry {
> + struct list_head list;
> + u16 id;
> + struct platform_device *pdev;
> + dln2_event_cb_t callback;
> +};
> +
> +int dln2_register_event_cb(struct platform_device *pdev, u16 id,
> +dln2_event_cb_t rx_cb)
> +{
> + struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
> + struct dln2_event_cb_entry *i, *new_cb;
Can you use a name which does not have the same suffix as the actual
callback function (i.e. "_cb"). Just call it "entry" or something.
> + unsigned long flags;
> + int ret = 0;
> +
> + new_cb = kmalloc(sizeof(*new_cb), GFP_KERNEL);
Use kzalloc here.
> + if (!new_cb)
> + return -ENOMEM;
> +
> + new_cb->id = id;
> + new_cb->callback = rx_cb;
> + new_cb->pdev = pdev;
> +
> + spin_lock_irqsave(&dln2->event_cb_lock, flags);
> +
> + list_for_each_entry(i, &dln2->event_cb_list, list) {
> + if (i->id == id) {
> + ret = -EBUSY;
> + break;
> + }
> + }
> +
> + if (!ret)
> + list_add_rcu(&new_cb->list, &dln2->event_cb_list);
> +
> + spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
> +
> + if (ret)
> + kfree(new_cb);
> +
> + 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_event_cb_entry *i;
> + unsigned long flags;
> + bool found = false;
> +
> + spin_lock_irqsave(&dln2->event_cb_lock, flags);
> +
> + list_for_each_entry(i, &dln2->event_cb_list, list) {
> + if (i->id == id) {
> + list_del_rcu(&i->list);
> + found = true;
> + break;
> + }
> + }
> +
> + spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
> +
> + if (found) {
> + synchronize_rcu();
> + kfree(i);
> + }
> +}
> +EXPORT_SYMBOL(dln2_unregister_event_cb);
> +
Please add a comment describing the return value (i.e. when the urb had
been saved and shouldn't be resubmitted).
Also could rename this helper so it doesn't appear to be a variant of
dln2_transfer (e.g. something with "complete" in the name).
> +static bool 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;
> + bool ret = false;
> +
> + rxc = &rxs->slots[rx_slot];
> +
> + /*
> + * No need to disable interrupts as this lock is not taken in
> + * interrupt context elsewhere in this driver and this
> + * function (or its callers) are not exported to other
> + * modules.
Why do you break comment lines already at 70 chars?
> + */
> + spin_lock(&rxs->lock);
> + if (rxc->in_use && !rxc->urb) {
> + rxc->urb = urb;
> + complete(&rxc->done);
> + ret = true;
> + }
> + spin_unlock(&rxs->lock);
> +
> + return ret;
> +}
> +
> +static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
> + void *data, int len)
> +{
> + struct dln2_event_cb_entry *i;
> +
> + rcu_read_lock();
> +
> + list_for_each_entry_rcu(i, &dln2->event_cb_list, list)
> + if (i->id == id)
> + i->callback(i->pdev, echo, data, len);
> +
> + rcu_read_unlock();
> +}
> +
> +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;
> + int 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 misma
[PATCH v8 1/4] mfd: add support for Diolan DLN-2 devices
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
---
drivers/mfd/Kconfig | 11 +
drivers/mfd/Makefile | 1 +
drivers/mfd/dln2.c | 756 +++
include/linux/mfd/dln2.h | 69 +
4 files changed, 837 insertions(+)
create mode 100644 drivers/mfd/dln2.c
create mode 100644 include/linux/mfd/dln2.h
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index c9200d3..4538815a 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -189,6 +189,17 @@ 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 such as I2C_DLN2, GPIO_DLN2,
+ etc. 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 61f8dbf..2cd7e74 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -175,6 +175,7 @@ obj-$(CONFIG_MFD_STW481X) += stw481x.o
obj-$(CONFIG_MFD_IPAQ_MICRO) += ipaq-micro.o
obj-$(CONFIG_MFD_MENF21BMC)+= menf21bmc.o
obj-$(CONFIG_MFD_HI6421_PMIC) += hi6421-pmic-core.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 000..124b262
--- /dev/null
+++ b/drivers/mfd/dln2.c
@@ -0,0 +1,756 @@
+/*
+ * 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
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+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_URBS 16
+#define DLN2_RX_BUF_SIZE 512
+
+enum dln2_handle {
+ DLN2_HANDLE_EVENT = 0, /* don't change, hardware defined */
+ DLN2_HANDLE_CTRL,
+ DLN2_HANDLE_GPIO,
+ DLN2_HANDLE_I2C,
+ DLN2_HANDLES
+};
+
+/*
+ * 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 {
+ /* completion used to wait for a response */
+ struct completion done;
+
+ /* if non-NULL the URB contains the response */
+ struct urb *urb;
+
+ /* if true then this context is used to wait for a response */
+ bool in_use;
+};
+
+/*
+ * Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We
+ * use the handle header field to identify 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 particu
