[v5] USB: serial: ftdi_sio: Add MTP NVM support

Message ID 1529930142-14304-1-git-send-email-loic.poulain@linaro.org
State Superseded
Headers show
Series
  • [v5] USB: serial: ftdi_sio: Add MTP NVM support
Related show

Commit Message

Loic Poulain June 25, 2018, 12:35 p.m.
Most of FTDI's devices have an EEPROM which records FTDI devices
configuration setting (e.g. the VID, PID, I/O config...) and user
data. For example, FT232R and FTX chips have 128-byte and 2048-byte
internal EEPROM respectively.

This patch adds support for FTDI EEPROM read/write via USB control
transfers and register a new nvm device to the nvmem core.

This permits to expose the EEPROM as a sysfs file, allowing userspace
to read/modify FTDI configuration and its user data without having to
rely on a specific userspace USB driver.

Moreover, any upcoming new tentative to add CBUS GPIO support could
integrate CBUS EEPROM configuration reading in order to determine
which of the CBUS pins are available as GPIO.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

---
 v2: Use ifdef instead of IS_ENABLED
     error message in case of nvmem registering failure
     Fix space/tab in Kconfig
 v3: Make nvmem a child of the usb dev instead of the serial port
     Add macros defining eeprom sizes
     Check read/write size is a nultiple of the eeprom word-size
     Remove useless change in Kconfig
 v4: Reword commit message
     Remove default-yes from Kconfig
     Change includes ordering
     Use default linux size defines
     Use get_unaligned_le16 helper
     Prepend EEPROM functions with ftdi_
     Error message in ftdi_eeprom_register()
 v5: Fix missing linux/sizes header

 drivers/usb/serial/Kconfig    |  10 ++++
 drivers/usb/serial/ftdi_sio.c | 119 ++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/serial/ftdi_sio.h |  28 ++++++++++
 3 files changed, 157 insertions(+)

-- 
2.7.4

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Comments

Andy Shevchenko June 26, 2018, 11:02 a.m. | #1
On Mon, Jun 25, 2018 at 3:35 PM, Loic Poulain <loic.poulain@linaro.org> wrote:
> Most of FTDI's devices have an EEPROM which records FTDI devices

> configuration setting (e.g. the VID, PID, I/O config...) and user

> data. For example, FT232R and FTX chips have 128-byte and 2048-byte

> internal EEPROM respectively.

>

> This patch adds support for FTDI EEPROM read/write via USB control

> transfers and register a new nvm device to the nvmem core.

>

> This permits to expose the EEPROM as a sysfs file, allowing userspace

> to read/modify FTDI configuration and its user data without having to

> rely on a specific userspace USB driver.

>

> Moreover, any upcoming new tentative to add CBUS GPIO support could

> integrate CBUS EEPROM configuration reading in order to determine

> which of the CBUS pins are available as GPIO.

>


FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>


One nit below, though.

> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

> ---

>  v2: Use ifdef instead of IS_ENABLED

>      error message in case of nvmem registering failure

>      Fix space/tab in Kconfig

>  v3: Make nvmem a child of the usb dev instead of the serial port

>      Add macros defining eeprom sizes

>      Check read/write size is a nultiple of the eeprom word-size

>      Remove useless change in Kconfig

>  v4: Reword commit message

>      Remove default-yes from Kconfig

>      Change includes ordering

>      Use default linux size defines

>      Use get_unaligned_le16 helper

>      Prepend EEPROM functions with ftdi_

>      Error message in ftdi_eeprom_register()

>  v5: Fix missing linux/sizes header

>

>  drivers/usb/serial/Kconfig    |  10 ++++

>  drivers/usb/serial/ftdi_sio.c | 119 ++++++++++++++++++++++++++++++++++++++++++

>  drivers/usb/serial/ftdi_sio.h |  28 ++++++++++

>  3 files changed, 157 insertions(+)

>

> diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig

> index 533f127..5747562 100644

> --- a/drivers/usb/serial/Kconfig

> +++ b/drivers/usb/serial/Kconfig

> @@ -181,6 +181,16 @@ config USB_SERIAL_FTDI_SIO

>           To compile this driver as a module, choose M here: the

>           module will be called ftdi_sio.

>

> +config USB_SERIAL_FTDI_SIO_NVMEM

> +       bool "FTDI MTP non-volatile memory support"

> +       depends on USB_SERIAL_FTDI_SIO

> +       select NVMEM

> +       help

> +         Say yes here to add support for the MTP non-volatile memory

> +         present on FTDI. Most of FTDI's devices have an EEPROM which

> +         records FTDI device's configuration setting as well as user

> +         data.

> +

>  config USB_SERIAL_VISOR

>         tristate "USB Handspring Visor / Palm m50x / Sony Clie Driver"

>         help

> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c

> index 7ea221d..75a35a8 100644

> --- a/drivers/usb/serial/ftdi_sio.c

> +++ b/drivers/usb/serial/ftdi_sio.c

> @@ -37,9 +37,13 @@

>  #include <linux/spinlock.h>

>  #include <linux/mutex.h>

>  #include <linux/uaccess.h>

> +#include <linux/sizes.h>

> +#include <linux/nvmem-provider.h>

>  #include <linux/usb.h>

>  #include <linux/serial.h>

>  #include <linux/usb/serial.h>

> +#include <asm/unaligned.h>

> +


I would put it rather as follows

+#include <linux/nvmem-provider.h>
... // something else is still in order here?
+#include <linux/sizes.h>
#include <linux/spinlock.h>
 #include <linux/mutex.h>
 #include <linux/uaccess.h>
 #include <linux/usb.h>
 #include <linux/serial.h>
 #include <linux/usb/serial.h>
+
+#include <asm/unaligned.h>
+

// also note another blank line as divider.

>  #include "ftdi_sio.h"

>  #include "ftdi_sio_ids.h"

>

> @@ -73,6 +77,8 @@ struct ftdi_private {

>         unsigned int latency;           /* latency setting in use */

>         unsigned short max_packet_size;

>         struct mutex cfg_lock; /* Avoid mess by parallel calls of config ioctl() and change_speed() */

> +

> +       struct nvmem_device *eeprom;

>  };

>

>  /* struct ftdi_sio_quirk is used by devices requiring special attention. */

> @@ -1529,6 +1535,112 @@ static int get_lsr_info(struct usb_serial_port *port,

>         return 0;

>  }

>

> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

> +

> +static int ftdi_write_eeprom(void *priv, unsigned int off, void *val,

> +                            size_t bytes)

> +{

> +       struct usb_serial_port *port = priv;

> +       struct usb_device *udev = port->serial->dev;


> +       unsigned char *buf = val;


Btw, not sure why you need this now...

> +

> +       if (bytes % 2) /* 16-bit eeprom */

> +               return -EINVAL;

> +

> +       while (bytes) {

> +               int rv;

> +

> +               rv = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),

> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST,

> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE,

> +                                    get_unaligned_le16(buf), off / 2, NULL,

> +                                    0, WDR_TIMEOUT);

> +               if (rv < 0)

> +                       return rv;

> +

> +               off += 2;

> +               buf += 2;

> +               bytes -= 2;

> +       }

> +

> +       return 0;

> +}

> +

> +static int ftdi_read_eeprom(void *priv, unsigned int off, void *val,

> +                           size_t bytes)

> +{

> +       struct usb_serial_port *port = priv;

> +       struct usb_device *udev = port->serial->dev;


> +       unsigned char *buf = val;


Ditto.

> +

> +       if (bytes % 2) /* 16-bit eeprom */

> +               return -EINVAL;

> +

> +       while (bytes) {

> +               int rv;

> +

> +               rv = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),

> +                                    FTDI_SIO_READ_EEPROM_REQUEST,

> +                                    FTDI_SIO_READ_EEPROM_REQUEST_TYPE,

> +                                    0, off / 2, buf, 2, WDR_TIMEOUT);

> +               if (rv < 0)

> +                       return rv;

> +

> +               off += 2;

> +               buf += 2;

> +               bytes -= 2;

> +       }

> +

> +       return 0;

> +}

> +

> +static int ftdi_register_eeprom(struct usb_serial_port *port)

> +{

> +       struct ftdi_private *priv = usb_get_serial_port_data(port);

> +       struct usb_device *udev = port->serial->dev;

> +       struct nvmem_config nvmconf = {};

> +

> +       switch (priv->chip_type) {

> +       case FTX:

> +               nvmconf.size = SZ_2K;

> +               break;

> +       case FT232RL:

> +               nvmconf.size = SZ_128;

> +               break;

> +       default:

> +               return 0;

> +       }

> +

> +       nvmconf.word_size = 2;

> +       nvmconf.stride = 2;

> +       nvmconf.read_only = false;

> +       nvmconf.priv = port;

> +       nvmconf.dev = &udev->dev;

> +       nvmconf.reg_read = ftdi_read_eeprom;

> +       nvmconf.reg_write = ftdi_write_eeprom;

> +       nvmconf.owner = THIS_MODULE;

> +

> +       priv->eeprom = nvmem_register(&nvmconf);

> +       if (IS_ERR(priv->eeprom)) {

> +               dev_err(&udev->dev, "Unable to register FTDI EEPROM\n");

> +               priv->eeprom = NULL;

> +               return -ENOMEM;

> +       }

> +

> +       dev_info(&udev->dev, "Registered %d-byte FTDI EEPROM\n", nvmconf.size);

> +

> +       return 0;

> +}

> +

> +static void ftdi_unregister_eeprom(struct usb_serial_port *port)

> +{

> +       struct ftdi_private *priv = usb_get_serial_port_data(port);

> +

> +       if (priv->eeprom)

> +               nvmem_unregister(priv->eeprom);

> +}

> +

> +#endif /* CONFIG_USB_SERIAL_FTDI_SIO_NVMEM */

>

>  /* Determine type of FTDI chip based on USB config and descriptor. */

>  static void ftdi_determine_type(struct usb_serial_port *port)

> @@ -1814,6 +1926,10 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)

>                 priv->latency = 16;

>         write_latency_timer(port);

>         create_sysfs_attrs(port);

> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

> +       ftdi_register_eeprom(port);

> +#endif

> +

>         return 0;

>  }

>

> @@ -1931,6 +2047,9 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)

>  {

>         struct ftdi_private *priv = usb_get_serial_port_data(port);

>

> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

> +       ftdi_unregister_eeprom(port);

> +#endif

>         remove_sysfs_attrs(port);

>

>         kfree(priv);

> diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h

> index dcd0b6e..9eab961 100644

> --- a/drivers/usb/serial/ftdi_sio.h

> +++ b/drivers/usb/serial/ftdi_sio.h

> @@ -36,6 +36,8 @@

>  #define FTDI_SIO_SET_ERROR_CHAR                7 /* Set the error character */

>  #define FTDI_SIO_SET_LATENCY_TIMER     9 /* Set the latency timer */

>  #define FTDI_SIO_GET_LATENCY_TIMER     10 /* Get the latency timer */

> +#define FTDI_SIO_READ_EEPROM           0x90 /* Read eeprom */

> +#define FTDI_SIO_WRITE_EEPROM          0x91 /* Write eeprom */

>

>  /* Interface indices for FT2232, FT2232H and FT4232H devices */

>  #define INTERFACE_A            1

> @@ -400,6 +402,32 @@ enum ftdi_sio_baudrate {

>   *

>   */

>

> + /* FTDI_SIO_READ_EEPROM */

> +#define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0

> +#define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM

> +/*

> + *  BmRequestType:   1100 0000b

> + *  bRequest:        FTDI_SIO_READ_EEPROM

> + *  wValue:          0

> + *  wIndex:          Word Index

> + *  wLength:         2

> + *  Data:            return data (a word)

> + *

> + */

> +

> +/* FTDI_SIO_WRITE_EEPROM */

> +#define FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE 0x40

> +#define FTDI_SIO_WRITE_EEPROM_REQUEST FTDI_SIO_WRITE_EEPROM

> +/*

> + *  BmRequestType:   0100 0000b

> + *  bRequest:        FTDI_SIO_WRITE_EEPROM

> + *  wValue:          Data (word)

> + *  wIndex:          Word Index

> + *  wLength:         0

> + *  Data:            None

> + *

> + */

> +

>  /* FTDI_SIO_GET_MODEM_STATUS */

>  /* Retrieve the current value of the modem status register */

>

> --

> 2.7.4

>




-- 
With Best Regards,
Andy Shevchenko
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Loic Poulain June 26, 2018, 11:51 a.m. | #2
Hi Andy,

On 26 June 2018 at 13:02, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> On Mon, Jun 25, 2018 at 3:35 PM, Loic Poulain <loic.poulain@linaro.org> wrote:

>> Most of FTDI's devices have an EEPROM which records FTDI devices

>> configuration setting (e.g. the VID, PID, I/O config...) and user

>> data. For example, FT232R and FTX chips have 128-byte and 2048-byte

>> internal EEPROM respectively.

>>

>> This patch adds support for FTDI EEPROM read/write via USB control

>> transfers and register a new nvm device to the nvmem core.

>>

>> This permits to expose the EEPROM as a sysfs file, allowing userspace

>> to read/modify FTDI configuration and its user data without having to

>> rely on a specific userspace USB driver.

>>

>> Moreover, any upcoming new tentative to add CBUS GPIO support could

>> integrate CBUS EEPROM configuration reading in order to determine

>> which of the CBUS pins are available as GPIO.

>>

>

> FWIW,

> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

>

> One nit below, though.

>

>> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

>> ---

>>  v2: Use ifdef instead of IS_ENABLED

>>      error message in case of nvmem registering failure

>>      Fix space/tab in Kconfig

>>  v3: Make nvmem a child of the usb dev instead of the serial port

>>      Add macros defining eeprom sizes

>>      Check read/write size is a nultiple of the eeprom word-size

>>      Remove useless change in Kconfig

>>  v4: Reword commit message

>>      Remove default-yes from Kconfig

>>      Change includes ordering

>>      Use default linux size defines

>>      Use get_unaligned_le16 helper

>>      Prepend EEPROM functions with ftdi_

>>      Error message in ftdi_eeprom_register()

>>  v5: Fix missing linux/sizes header

>>

>>  drivers/usb/serial/Kconfig    |  10 ++++

>>  drivers/usb/serial/ftdi_sio.c | 119 ++++++++++++++++++++++++++++++++++++++++++

>>  drivers/usb/serial/ftdi_sio.h |  28 ++++++++++

>>  3 files changed, 157 insertions(+)

>>

>> diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig

>> index 533f127..5747562 100644

>> --- a/drivers/usb/serial/Kconfig

>> +++ b/drivers/usb/serial/Kconfig

>> @@ -181,6 +181,16 @@ config USB_SERIAL_FTDI_SIO

>>           To compile this driver as a module, choose M here: the

>>           module will be called ftdi_sio.

>>

>> +config USB_SERIAL_FTDI_SIO_NVMEM

>> +       bool "FTDI MTP non-volatile memory support"

>> +       depends on USB_SERIAL_FTDI_SIO

>> +       select NVMEM

>> +       help

>> +         Say yes here to add support for the MTP non-volatile memory

>> +         present on FTDI. Most of FTDI's devices have an EEPROM which

>> +         records FTDI device's configuration setting as well as user

>> +         data.

>> +

>>  config USB_SERIAL_VISOR

>>         tristate "USB Handspring Visor / Palm m50x / Sony Clie Driver"

>>         help

>> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c

>> index 7ea221d..75a35a8 100644

>> --- a/drivers/usb/serial/ftdi_sio.c

>> +++ b/drivers/usb/serial/ftdi_sio.c

>> @@ -37,9 +37,13 @@

>>  #include <linux/spinlock.h>

>>  #include <linux/mutex.h>

>>  #include <linux/uaccess.h>

>> +#include <linux/sizes.h>

>> +#include <linux/nvmem-provider.h>

>>  #include <linux/usb.h>

>>  #include <linux/serial.h>

>>  #include <linux/usb/serial.h>

>> +#include <asm/unaligned.h>

>> +

>

> I would put it rather as follows

>

> +#include <linux/nvmem-provider.h>

> ... // something else is still in order here?

> +#include <linux/sizes.h>

> #include <linux/spinlock.h>

>  #include <linux/mutex.h>

>  #include <linux/uaccess.h>

>  #include <linux/usb.h>

>  #include <linux/serial.h>

>  #include <linux/usb/serial.h>

> +

> +#include <asm/unaligned.h>

> +

>

> // also note another blank line as divider.

>


Ok !

>>  #include "ftdi_sio.h"

>>  #include "ftdi_sio_ids.h"

>>

>> @@ -73,6 +77,8 @@ struct ftdi_private {

>>         unsigned int latency;           /* latency setting in use */

>>         unsigned short max_packet_size;

>>         struct mutex cfg_lock; /* Avoid mess by parallel calls of config ioctl() and change_speed() */

>> +

>> +       struct nvmem_device *eeprom;

>>  };

>>

>>  /* struct ftdi_sio_quirk is used by devices requiring special attention. */

>> @@ -1529,6 +1535,112 @@ static int get_lsr_info(struct usb_serial_port *port,

>>         return 0;

>>  }

>>

>> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

>> +

>> +static int ftdi_write_eeprom(void *priv, unsigned int off, void *val,

>> +                            size_t bytes)

>> +{

>> +       struct usb_serial_port *port = priv;

>> +       struct usb_device *udev = port->serial->dev;

>

>> +       unsigned char *buf = val;

>

> Btw, not sure why you need this now...


Not needed indeed, just wanted to avoid arithmetic on void pointer,
but I can cast instead.

>

>> +

>> +       if (bytes % 2) /* 16-bit eeprom */

>> +               return -EINVAL;

>> +

>> +       while (bytes) {

>> +               int rv;

>> +

>> +               rv = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),

>> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST,

>> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE,

>> +                                    get_unaligned_le16(buf), off / 2, NULL,

>> +                                    0, WDR_TIMEOUT);

>> +               if (rv < 0)

>> +                       return rv;

>> +

>> +               off += 2;

>> +               buf += 2;

>> +               bytes -= 2;

>> +       }

>> +

>> +       return 0;

>> +}

>> +

>> +static int ftdi_read_eeprom(void *priv, unsigned int off, void *val,

>> +                           size_t bytes)

>> +{

>> +       struct usb_serial_port *port = priv;

>> +       struct usb_device *udev = port->serial->dev;

>

>> +       unsigned char *buf = val;

>

> Ditto.

>

>> +

>> +       if (bytes % 2) /* 16-bit eeprom */

>> +               return -EINVAL;

>> +

>> +       while (bytes) {

>> +               int rv;

>> +

>> +               rv = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),

>> +                                    FTDI_SIO_READ_EEPROM_REQUEST,

>> +                                    FTDI_SIO_READ_EEPROM_REQUEST_TYPE,

>> +                                    0, off / 2, buf, 2, WDR_TIMEOUT);

>> +               if (rv < 0)

>> +                       return rv;

>> +

>> +               off += 2;

>> +               buf += 2;

>> +               bytes -= 2;

>> +       }

>> +

>> +       return 0;

>> +}

>> +

>> +static int ftdi_register_eeprom(struct usb_serial_port *port)

>> +{

>> +       struct ftdi_private *priv = usb_get_serial_port_data(port);

>> +       struct usb_device *udev = port->serial->dev;

>> +       struct nvmem_config nvmconf = {};

>> +

>> +       switch (priv->chip_type) {

>> +       case FTX:

>> +               nvmconf.size = SZ_2K;

>> +               break;

>> +       case FT232RL:

>> +               nvmconf.size = SZ_128;

>> +               break;

>> +       default:

>> +               return 0;

>> +       }

>> +

>> +       nvmconf.word_size = 2;

>> +       nvmconf.stride = 2;

>> +       nvmconf.read_only = false;

>> +       nvmconf.priv = port;

>> +       nvmconf.dev = &udev->dev;

>> +       nvmconf.reg_read = ftdi_read_eeprom;

>> +       nvmconf.reg_write = ftdi_write_eeprom;

>> +       nvmconf.owner = THIS_MODULE;

>> +

>> +       priv->eeprom = nvmem_register(&nvmconf);

>> +       if (IS_ERR(priv->eeprom)) {

>> +               dev_err(&udev->dev, "Unable to register FTDI EEPROM\n");

>> +               priv->eeprom = NULL;

>> +               return -ENOMEM;

>> +       }

>> +

>> +       dev_info(&udev->dev, "Registered %d-byte FTDI EEPROM\n", nvmconf.size);

>> +

>> +       return 0;

>> +}

>> +

>> +static void ftdi_unregister_eeprom(struct usb_serial_port *port)

>> +{

>> +       struct ftdi_private *priv = usb_get_serial_port_data(port);

>> +

>> +       if (priv->eeprom)

>> +               nvmem_unregister(priv->eeprom);

>> +}

>> +

>> +#endif /* CONFIG_USB_SERIAL_FTDI_SIO_NVMEM */

>>

>>  /* Determine type of FTDI chip based on USB config and descriptor. */

>>  static void ftdi_determine_type(struct usb_serial_port *port)

>> @@ -1814,6 +1926,10 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)

>>                 priv->latency = 16;

>>         write_latency_timer(port);

>>         create_sysfs_attrs(port);

>> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

>> +       ftdi_register_eeprom(port);

>> +#endif

>> +

>>         return 0;

>>  }

>>

>> @@ -1931,6 +2047,9 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)

>>  {

>>         struct ftdi_private *priv = usb_get_serial_port_data(port);

>>

>> +#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM

>> +       ftdi_unregister_eeprom(port);

>> +#endif

>>         remove_sysfs_attrs(port);

>>

>>         kfree(priv);

>> diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h

>> index dcd0b6e..9eab961 100644

>> --- a/drivers/usb/serial/ftdi_sio.h

>> +++ b/drivers/usb/serial/ftdi_sio.h

>> @@ -36,6 +36,8 @@

>>  #define FTDI_SIO_SET_ERROR_CHAR                7 /* Set the error character */

>>  #define FTDI_SIO_SET_LATENCY_TIMER     9 /* Set the latency timer */

>>  #define FTDI_SIO_GET_LATENCY_TIMER     10 /* Get the latency timer */

>> +#define FTDI_SIO_READ_EEPROM           0x90 /* Read eeprom */

>> +#define FTDI_SIO_WRITE_EEPROM          0x91 /* Write eeprom */

>>

>>  /* Interface indices for FT2232, FT2232H and FT4232H devices */

>>  #define INTERFACE_A            1

>> @@ -400,6 +402,32 @@ enum ftdi_sio_baudrate {

>>   *

>>   */

>>

>> + /* FTDI_SIO_READ_EEPROM */

>> +#define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0

>> +#define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM

>> +/*

>> + *  BmRequestType:   1100 0000b

>> + *  bRequest:        FTDI_SIO_READ_EEPROM

>> + *  wValue:          0

>> + *  wIndex:          Word Index

>> + *  wLength:         2

>> + *  Data:            return data (a word)

>> + *

>> + */

>> +

>> +/* FTDI_SIO_WRITE_EEPROM */

>> +#define FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE 0x40

>> +#define FTDI_SIO_WRITE_EEPROM_REQUEST FTDI_SIO_WRITE_EEPROM

>> +/*

>> + *  BmRequestType:   0100 0000b

>> + *  bRequest:        FTDI_SIO_WRITE_EEPROM

>> + *  wValue:          Data (word)

>> + *  wIndex:          Word Index

>> + *  wLength:         0

>> + *  Data:            None

>> + *

>> + */

>> +

>>  /* FTDI_SIO_GET_MODEM_STATUS */

>>  /* Retrieve the current value of the modem status register */

>>

>> --

>> 2.7.4

>>

>

>

>

> --

> With Best Regards,

> Andy Shevchenko


Regards,
Loic
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Andy Shevchenko June 26, 2018, 12:57 p.m. | #3
On Tue, Jun 26, 2018 at 2:51 PM, Loic Poulain <loic.poulain@linaro.org> wrote:
> On 26 June 2018 at 13:02, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

>> On Mon, Jun 25, 2018 at 3:35 PM, Loic Poulain <loic.poulain@linaro.org> wrote:




>>> +       unsigned char *buf = val;

>>

>> Btw, not sure why you need this now...

>

> Not needed indeed, just wanted to avoid arithmetic on void pointer,

> but I can cast instead.


No need to cast either.
We rely (?) on GCC to allow pointer arithmetic on void pointers to
behave as char pointers.

(?) I don't know if it's deliberate choice, though a lot of code uses
pointer arithmetic against void pointers such if it would be a char
pointers.

In case you would like to keep it, the temporary variable looks the
best way (no ugly castings, please).

>>> +

>>> +       if (bytes % 2) /* 16-bit eeprom */

>>> +               return -EINVAL;

>>> +

>>> +       while (bytes) {

>>> +               int rv;

>>> +

>>> +               rv = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),

>>> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST,

>>> +                                    FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE,

>>> +                                    get_unaligned_le16(buf), off / 2, NULL,

>>> +                                    0, WDR_TIMEOUT);

>>> +               if (rv < 0)

>>> +                       return rv;

>>> +

>>> +               off += 2;

>>> +               buf += 2;

>>> +               bytes -= 2;

>>> +       }



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Andy Shevchenko
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Andy Shevchenko June 26, 2018, 12:59 p.m. | #4
On Tue, Jun 26, 2018 at 3:57 PM, Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:

Just noticed you have sent v6.
I'm pretty fine with it, thanks!


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Patch

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 533f127..5747562 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -181,6 +181,16 @@  config USB_SERIAL_FTDI_SIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called ftdi_sio.
 
+config USB_SERIAL_FTDI_SIO_NVMEM
+	bool "FTDI MTP non-volatile memory support"
+	depends on USB_SERIAL_FTDI_SIO
+	select NVMEM
+	help
+	  Say yes here to add support for the MTP non-volatile memory
+	  present on FTDI. Most of FTDI's devices have an EEPROM which
+	  records FTDI device's configuration setting as well as user
+	  data.
+
 config USB_SERIAL_VISOR
 	tristate "USB Handspring Visor / Palm m50x / Sony Clie Driver"
 	help
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 7ea221d..75a35a8 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -37,9 +37,13 @@ 
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
 #include <linux/uaccess.h>
+#include <linux/sizes.h>
+#include <linux/nvmem-provider.h>
 #include <linux/usb.h>
 #include <linux/serial.h>
 #include <linux/usb/serial.h>
+#include <asm/unaligned.h>
+
 #include "ftdi_sio.h"
 #include "ftdi_sio_ids.h"
 
@@ -73,6 +77,8 @@  struct ftdi_private {
 	unsigned int latency;		/* latency setting in use */
 	unsigned short max_packet_size;
 	struct mutex cfg_lock; /* Avoid mess by parallel calls of config ioctl() and change_speed() */
+
+	struct nvmem_device *eeprom;
 };
 
 /* struct ftdi_sio_quirk is used by devices requiring special attention. */
@@ -1529,6 +1535,112 @@  static int get_lsr_info(struct usb_serial_port *port,
 	return 0;
 }
 
+#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM
+
+static int ftdi_write_eeprom(void *priv, unsigned int off, void *val,
+			     size_t bytes)
+{
+	struct usb_serial_port *port = priv;
+	struct usb_device *udev = port->serial->dev;
+	unsigned char *buf = val;
+
+	if (bytes % 2) /* 16-bit eeprom */
+		return -EINVAL;
+
+	while (bytes) {
+		int rv;
+
+		rv = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				     FTDI_SIO_WRITE_EEPROM_REQUEST,
+				     FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE,
+				     get_unaligned_le16(buf), off / 2, NULL,
+				     0, WDR_TIMEOUT);
+		if (rv < 0)
+			return rv;
+
+		off += 2;
+		buf += 2;
+		bytes -= 2;
+	}
+
+	return 0;
+}
+
+static int ftdi_read_eeprom(void *priv, unsigned int off, void *val,
+			    size_t bytes)
+{
+	struct usb_serial_port *port = priv;
+	struct usb_device *udev = port->serial->dev;
+	unsigned char *buf = val;
+
+	if (bytes % 2) /* 16-bit eeprom */
+		return -EINVAL;
+
+	while (bytes) {
+		int rv;
+
+		rv = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+				     FTDI_SIO_READ_EEPROM_REQUEST,
+				     FTDI_SIO_READ_EEPROM_REQUEST_TYPE,
+				     0, off / 2, buf, 2, WDR_TIMEOUT);
+		if (rv < 0)
+			return rv;
+
+		off += 2;
+		buf += 2;
+		bytes -= 2;
+	}
+
+	return 0;
+}
+
+static int ftdi_register_eeprom(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	struct usb_device *udev = port->serial->dev;
+	struct nvmem_config nvmconf = {};
+
+	switch (priv->chip_type) {
+	case FTX:
+		nvmconf.size = SZ_2K;
+		break;
+	case FT232RL:
+		nvmconf.size = SZ_128;
+		break;
+	default:
+		return 0;
+	}
+
+	nvmconf.word_size = 2;
+	nvmconf.stride = 2;
+	nvmconf.read_only = false;
+	nvmconf.priv = port;
+	nvmconf.dev = &udev->dev;
+	nvmconf.reg_read = ftdi_read_eeprom;
+	nvmconf.reg_write = ftdi_write_eeprom;
+	nvmconf.owner = THIS_MODULE;
+
+	priv->eeprom = nvmem_register(&nvmconf);
+	if (IS_ERR(priv->eeprom)) {
+		dev_err(&udev->dev, "Unable to register FTDI EEPROM\n");
+		priv->eeprom = NULL;
+		return -ENOMEM;
+	}
+
+	dev_info(&udev->dev, "Registered %d-byte FTDI EEPROM\n", nvmconf.size);
+
+	return 0;
+}
+
+static void ftdi_unregister_eeprom(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	if (priv->eeprom)
+		nvmem_unregister(priv->eeprom);
+}
+
+#endif /* CONFIG_USB_SERIAL_FTDI_SIO_NVMEM */
 
 /* Determine type of FTDI chip based on USB config and descriptor. */
 static void ftdi_determine_type(struct usb_serial_port *port)
@@ -1814,6 +1926,10 @@  static int ftdi_sio_port_probe(struct usb_serial_port *port)
 		priv->latency = 16;
 	write_latency_timer(port);
 	create_sysfs_attrs(port);
+#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM
+	ftdi_register_eeprom(port);
+#endif
+
 	return 0;
 }
 
@@ -1931,6 +2047,9 @@  static int ftdi_sio_port_remove(struct usb_serial_port *port)
 {
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
 
+#ifdef CONFIG_USB_SERIAL_FTDI_SIO_NVMEM
+	ftdi_unregister_eeprom(port);
+#endif
 	remove_sysfs_attrs(port);
 
 	kfree(priv);
diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h
index dcd0b6e..9eab961 100644
--- a/drivers/usb/serial/ftdi_sio.h
+++ b/drivers/usb/serial/ftdi_sio.h
@@ -36,6 +36,8 @@ 
 #define FTDI_SIO_SET_ERROR_CHAR		7 /* Set the error character */
 #define FTDI_SIO_SET_LATENCY_TIMER	9 /* Set the latency timer */
 #define FTDI_SIO_GET_LATENCY_TIMER	10 /* Get the latency timer */
+#define FTDI_SIO_READ_EEPROM		0x90 /* Read eeprom */
+#define FTDI_SIO_WRITE_EEPROM		0x91 /* Write eeprom */
 
 /* Interface indices for FT2232, FT2232H and FT4232H devices */
 #define INTERFACE_A		1
@@ -400,6 +402,32 @@  enum ftdi_sio_baudrate {
  *
  */
 
+ /* FTDI_SIO_READ_EEPROM */
+#define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0
+#define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM
+/*
+ *  BmRequestType:   1100 0000b
+ *  bRequest:        FTDI_SIO_READ_EEPROM
+ *  wValue:          0
+ *  wIndex:          Word Index
+ *  wLength:         2
+ *  Data:            return data (a word)
+ *
+ */
+
+/* FTDI_SIO_WRITE_EEPROM */
+#define FTDI_SIO_WRITE_EEPROM_REQUEST_TYPE 0x40
+#define FTDI_SIO_WRITE_EEPROM_REQUEST FTDI_SIO_WRITE_EEPROM
+/*
+ *  BmRequestType:   0100 0000b
+ *  bRequest:        FTDI_SIO_WRITE_EEPROM
+ *  wValue:          Data (word)
+ *  wIndex:          Word Index
+ *  wLength:         0
+ *  Data:            None
+ *
+ */
+
 /* FTDI_SIO_GET_MODEM_STATUS */
 /* Retrieve the current value of the modem status register */