Add support to the uftdi driver for reading and writing the serial eeprom

that can be attached to the chips, via ioctl() calls.

3 files changed, 112 insertions, 1 deletions

diff --git a/sys/dev/usb/serial/uftdi.c b/sys/dev/usb/serial/uftdi.c
index c0dc79f18b11..cf468044b049 100644
--- a/sys/dev/usb/serial/uftdi.c
+++ b/sys/dev/usb/serial/uftdi.c
@@ -1791,6 +1791,82 @@ uftdi_set_error_char(struct ucom_softc *ucom, int echar)
 }
 
 static int
+uftdi_read_eeprom(struct ucom_softc *ucom, struct uftdi_eeio *eeio)
+{
+	struct uftdi_softc *sc = ucom->sc_parent;
+	usb_device_request_t req;
+	usb_error_t err;
+	uint16_t widx, wlength, woffset;
+
+	/* Offset and length must both be evenly divisible by two. */
+	if ((eeio->offset | eeio->length) & 0x01)
+		return (EINVAL);
+
+	woffset = eeio->offset / 2U;
+	wlength = eeio->length / 2U;
+	for (widx = 0; widx < wlength; widx++) {
+		req.bmRequestType = UT_READ_VENDOR_DEVICE;
+		req.bRequest = FTDI_SIO_READ_EEPROM;
+		USETW(req.wIndex, widx + woffset);
+		USETW(req.wLength, 2);
+		USETW(req.wValue, 0);
+		err = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req,
+		    &eeio->data[widx]);
+		if (err != USB_ERR_NORMAL_COMPLETION)
+			return (err);
+	}
+	return (USB_ERR_NORMAL_COMPLETION);
+}
+
+static int
+uftdi_write_eeprom(struct ucom_softc *ucom, struct uftdi_eeio *eeio)
+{
+	struct uftdi_softc *sc = ucom->sc_parent;
+	usb_device_request_t req;
+	usb_error_t err;
+	uint16_t widx, wlength, woffset;
+
+	/* Offset and length must both be evenly divisible by two. */
+	if ((eeio->offset | eeio->length) & 0x01)
+		return (EINVAL);
+
+	woffset = eeio->offset / 2U;
+	wlength = eeio->length / 2U;
+	for (widx = 0; widx < wlength; widx++) {
+		req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
+		req.bRequest = FTDI_SIO_WRITE_EEPROM;
+		USETW(req.wIndex, widx + woffset);
+		USETW(req.wLength, 0);
+		USETW(req.wValue, eeio->data[widx]);
+		err = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, NULL);
+		if (err != USB_ERR_NORMAL_COMPLETION)
+			return (err);
+	}
+	return (USB_ERR_NORMAL_COMPLETION);
+}
+
+static int
+uftdi_erase_eeprom(struct ucom_softc *ucom, int confirmation)
+{
+	struct uftdi_softc *sc = ucom->sc_parent;
+	usb_device_request_t req;
+	usb_error_t err;
+
+	/* Small effort to prevent accidental erasure. */
+	if (confirmation != UFTDI_CONFIRM_ERASE)
+		return (EINVAL);
+
+	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
+	req.bRequest = FTDI_SIO_ERASE_EEPROM;
+	USETW(req.wIndex, 0);
+	USETW(req.wLength, 0);
+	USETW(req.wValue, 0);
+	err = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, NULL);
+
+	return (err);
+}
+
+static int
 uftdi_ioctl(struct ucom_softc *ucom, uint32_t cmd, caddr_t data,
     int flag, struct thread *td)
 {
@@ -1833,6 +1909,15 @@ uftdi_ioctl(struct ucom_softc *ucom, uint32_t cmd, caddr_t data,
 		*(int *)data = sc->sc_bcdDevice;
 		err = 0;
 		break;
+	case UFTDIIOC_READ_EEPROM:
+		err = uftdi_read_eeprom(ucom, (struct uftdi_eeio *)data);
+		break;
+	case UFTDIIOC_WRITE_EEPROM:
+		err = uftdi_write_eeprom(ucom, (struct uftdi_eeio *)data);
+		break;
+	case UFTDIIOC_ERASE_EEPROM:
+		err = uftdi_erase_eeprom(ucom, *(int *)data);
+		break;
 	default:
 		return (ENOIOCTL);
 	}
diff --git a/sys/dev/usb/serial/uftdi_reg.h b/sys/dev/usb/serial/uftdi_reg.h
index a2d6e3876ae0..a1ea325b89a2 100644
--- a/sys/dev/usb/serial/uftdi_reg.h
+++ b/sys/dev/usb/serial/uftdi_reg.h
@@ -31,7 +31,10 @@
 #define	FTDI_SIO_SET_LATENCY	9	/* Set the latency timer */
 #define	FTDI_SIO_GET_LATENCY	10	/* Read the latency timer */
 #define	FTDI_SIO_SET_BITMODE	11	/* Set the bit bang I/O mode */
-#define	FTDI_SIO_GET_BITMODE	12	/* Read pin states in bit bang mode */
+#define	FTDI_SIO_GET_BITMODE	12	/* Read pin states from any mode */
+#define	FTDI_SIO_READ_EEPROM	144	/* Read eeprom word */
+#define	FTDI_SIO_WRITE_EEPROM	145	/* Write eeprom word */
+#define	FTDI_SIO_ERASE_EEPROM	146	/* Erase entire eeprom */
 
 /* Port Identifier Table */
 #define	FTDI_PIT_DEFAULT 	0	/* SIOA */
diff --git a/sys/dev/usb/uftdiio.h b/sys/dev/usb/uftdiio.h
index 0db2f3808756..4c6ecbc3f7ba 100644
--- a/sys/dev/usb/uftdiio.h
+++ b/sys/dev/usb/uftdiio.h
@@ -61,6 +61,26 @@ struct uftdi_bitmode
 	uint8_t iomask;
 };
 
+/*
+ * For UFTDIIOC_READ_EEPROM, UFTDIIOC_WRITE_EEPROM:
+ *
+ * IO is done in 16-bit words at the chip level; offset and length are in bytes,
+ * but must each be evenly divisible by two.
+ *
+ * It is not necessary to erase before writing.  For the FT232R device (only)
+ * you must set the latency timer to 0x77 before doing a series of eeprom writes
+ * (and restore it to the prior value when done).
+ */
+struct uftdi_eeio
+{
+	uint16_t offset;
+	uint16_t length;
+	uint16_t data[64];
+};
+
+/* Pass this value to confirm that eeprom erase request is not accidental. */
+#define	UFTDI_CONFIRM_ERASE	0x26139108
+
 #define	UFTDIIOC_RESET_IO	_IO('c', 0)	/* Reset config, flush fifos.*/
 #define	UFTDIIOC_RESET_RX	_IO('c', 1)	/* Flush input fifo. */
 #define	UFTDIIOC_RESET_TX	_IO('c', 2)	/* Flush output fifo. */
@@ -71,5 +91,8 @@ struct uftdi_bitmode
 #define	UFTDIIOC_SET_LATENCY	_IOW('c', 7, int)	/* 1-255 ms */
 #define	UFTDIIOC_GET_LATENCY	_IOR('c', 8, int)
 #define	UFTDIIOC_GET_HWREV	_IOR('c', 9, int)
+#define	UFTDIIOC_READ_EEPROM	_IOWR('c', 10, struct uftdi_eeio)
+#define	UFTDIIOC_WRITE_EEPROM	_IOW('c', 11, struct uftdi_eeio)
+#define	UFTDIIOC_ERASE_EEPROM	_IOW('c', 12, int)
 
 #endif