Module Name: src
Committed By: ryo
Date: Fri Sep 13 20:50:45 UTC 2019
Modified Files:
src/sys/dev/usb: uftdi.c uftdireg.h
Log Message:
Support serial speeds up to 12mbaud with newer FTDI chips.
baudrate calculation code uftdi_encode_baudrate() from FreeBSD uftdi.c@r330385
To generate a diff of this commit:
cvs rdiff -u -r1.70 -r1.71 src/sys/dev/usb/uftdi.c
cvs rdiff -u -r1.10 -r1.11 src/sys/dev/usb/uftdireg.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/usb/uftdi.c
diff -u src/sys/dev/usb/uftdi.c:1.70 src/sys/dev/usb/uftdi.c:1.71
--- src/sys/dev/usb/uftdi.c:1.70 Thu May 9 02:43:35 2019
+++ src/sys/dev/usb/uftdi.c Fri Sep 13 20:50:45 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: uftdi.c,v 1.70 2019/05/09 02:43:35 mrg Exp $ */
+/* $NetBSD: uftdi.c,v 1.71 2019/09/13 20:50:45 ryo Exp $ */
/*
* Copyright (c) 2000 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uftdi.c,v 1.70 2019/05/09 02:43:35 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uftdi.c,v 1.71 2019/09/13 20:50:45 ryo Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -85,6 +85,10 @@ struct uftdi_softc {
int sc_iface_no;
enum uftdi_type sc_type;
+ u_int sc_flags;
+#define FLAGS_BAUDCLK_12M 0x00000001
+#define FLAGS_ROUNDOFF_232A 0x00000002
+#define FLAGS_BAUDBITS_HINDEX 0x00000004
u_int sc_hdrlen;
u_int sc_chiptype;
@@ -96,7 +100,6 @@ struct uftdi_softc {
bool sc_dying;
u_int last_lcr;
-
};
static void uftdi_get_status(void *, int, u_char *, u_char *);
@@ -225,15 +228,46 @@ uftdi_attach(device_t parent, device_t s
sc->sc_iface_no = uiaa->uiaa_ifaceno;
sc->sc_type = UFTDI_TYPE_8U232AM; /* most devices are post-8U232AM */
sc->sc_hdrlen = 0;
- if (uiaa->uiaa_vendor == USB_VENDOR_FTDI
- && uiaa->uiaa_product == USB_PRODUCT_FTDI_SERIAL_8U100AX) {
- sc->sc_type = UFTDI_TYPE_SIO;
- sc->sc_hdrlen = 1;
- }
ddesc = usbd_get_device_descriptor(dev);
sc->sc_chiptype = UGETW(ddesc->bcdDevice);
+ switch (sc->sc_chiptype) {
+ case 0x0200:
+ if (ddesc->iSerialNumber != 0)
+ sc->sc_flags |= FLAGS_ROUNDOFF_232A;
+ ucaa.ucaa_portno = 0;
+ break;
+ case 0x0400:
+ ucaa.ucaa_portno = 0;
+ break;
+ case 0x0500:
+ sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
+ ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
+ break;
+ case 0x0600:
+ ucaa.ucaa_portno = 0;
+ break;
+ case 0x0700:
+ case 0x0800:
+ case 0x0900:
+ sc->sc_flags |= FLAGS_BAUDCLK_12M;
+ sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
+ ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
+ break;
+ case 0x1000:
+ sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
+ ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
+ break;
+ default:
+ if (sc->sc_chiptype < 0x0200) {
+ sc->sc_type = UFTDI_TYPE_SIO;
+ sc->sc_hdrlen = 1;
+ }
+ ucaa.ucaa_portno = 0;
+ break;
+ }
+
id = usbd_get_interface_descriptor(iface);
sc->sc_iface = iface;
@@ -281,7 +315,6 @@ uftdi_attach(device_t parent, device_t s
goto bad;
}
- ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
/* ucaa_bulkin, ucaa_bulkout set above */
if (ucaa.ucaa_ibufsize == 0)
ucaa.ucaa_ibufsize = UFTDIIBUFSIZE;
@@ -469,13 +502,130 @@ uftdi_set(void *vsc, int portno, int reg
(void)usbd_do_request(sc->sc_udev, &req, NULL);
}
+/*
+ * Return true if the given speed is within operational tolerance of the target
+ * speed. FTDI recommends that the hardware speed be within 3% of nominal.
+ */
+static inline bool
+uftdi_baud_within_tolerance(uint64_t speed, uint64_t target)
+{
+ return ((speed >= (target * 100) / 103) &&
+ (speed <= (target * 100) / 97));
+}
+
+static int
+uftdi_encode_baudrate(struct uftdi_softc *sc, int speed, int *rate, int *ratehi)
+{
+ static const uint8_t encoded_fraction[8] = {
+ 0, 3, 2, 4, 1, 5, 6, 7
+ };
+ static const uint8_t roundoff_232a[16] = {
+ 0, 1, 0, 1, 0, -1, 2, 1,
+ 0, -1, -2, -3, 4, 3, 2, 1,
+ };
+ uint32_t clk, divisor, fastclk_flag, frac, hwspeed;
+
+ /*
+ * If this chip has the fast clock capability and the speed is within
+ * range, use the 12MHz clock, otherwise the standard clock is 3MHz.
+ */
+ if ((sc->sc_flags & FLAGS_BAUDCLK_12M) && speed >= 1200) {
+ clk = 12000000;
+ fastclk_flag = (1 << 17);
+ } else {
+ clk = 3000000;
+ fastclk_flag = 0;
+ }
+
+ /*
+ * Make sure the requested speed is reachable with the available clock
+ * and a 14-bit divisor.
+ */
+ if (speed < (clk >> 14) || speed > clk)
+ return -1;
+
+ /*
+ * Calculate the divisor, initially yielding a fixed point number with a
+ * 4-bit (1/16ths) fraction, then round it to the nearest fraction the
+ * hardware can handle. When the integral part of the divisor is
+ * greater than one, the fractional part is in 1/8ths of the base clock.
+ * The FT8U232AM chips can handle only 0.125, 0.250, and 0.5 fractions.
+ * Later chips can handle all 1/8th fractions.
+ *
+ * If the integral part of the divisor is 1, a special rule applies: the
+ * fractional part can only be .0 or .5 (this is a limitation of the
+ * hardware). We handle this by truncating the fraction rather than
+ * rounding, because this only applies to the two fastest speeds the
+ * chip can achieve and rounding doesn't matter, either you've asked for
+ * that exact speed or you've asked for something the chip can't do.
+ *
+ * For the FT8U232AM chips, use a roundoff table to adjust the result
+ * to the nearest 1/8th fraction that is supported by the hardware,
+ * leaving a fixed-point number with a 3-bit fraction which exactly
+ * represents the math the hardware divider will do. For later-series
+ * chips that support all 8 fractional divisors, just round 16ths to
+ * 8ths by adding 1 and dividing by 2.
+ */
+ divisor = (clk << 4) / speed;
+ if ((divisor & 0xf) == 1)
+ divisor &= 0xfffffff8;
+ else if (sc->sc_flags & FLAGS_ROUNDOFF_232A)
+ divisor += roundoff_232a[divisor & 0x0f];
+ else
+ divisor += 1; /* Rounds odd 16ths up to next 8th. */
+ divisor >>= 1;
+
+ /*
+ * Ensure the resulting hardware speed will be within operational
+ * tolerance (within 3% of nominal).
+ */
+ hwspeed = (clk << 3) / divisor;
+ if (!uftdi_baud_within_tolerance(hwspeed, speed))
+ return -1;
+
+ /*
+ * Re-pack the divisor into hardware format. The lower 14-bits hold the
+ * integral part, while the upper bits specify the fraction by indexing
+ * a table of fractions within the hardware which is laid out as:
+ * {0.0, 0.5, 0.25, 0.125, 0.325, 0.625, 0.725, 0.875}
+ * The A-series chips only have the first four table entries; the
+ * roundoff table logic above ensures that the fractional part for those
+ * chips will be one of the first four values.
+ *
+ * When the divisor is 1 a special encoding applies: 1.0 is encoded as
+ * 0.0, and 1.5 is encoded as 1.0. The rounding logic above has already
+ * ensured that the fraction is either .0 or .5 if the integral is 1.
+ */
+ frac = divisor & 0x07;
+ divisor >>= 3;
+ if (divisor == 1) {
+ if (frac == 0)
+ divisor = 0; /* 1.0 becomes 0.0 */
+ else
+ frac = 0; /* 1.5 becomes 1.0 */
+ }
+ divisor |= (encoded_fraction[frac] << 14) | fastclk_flag;
+
+ *rate = (uint16_t)divisor;
+ *ratehi = (uint16_t)(divisor >> 16);
+
+ /*
+ * If this chip requires the baud bits to be in the high byte of the
+ * index word, move the bits up to that location.
+ */
+ if (sc->sc_flags & FLAGS_BAUDBITS_HINDEX)
+ *ratehi <<= 8;
+
+ return 0;
+}
+
static int
uftdi_param(void *vsc, int portno, struct termios *t)
{
struct uftdi_softc *sc = vsc;
usb_device_request_t req;
usbd_status err;
- int rate, data, flow;
+ int rate, ratehi, rerr, data, flow;
DPRINTF(("uftdi_param: sc=%p\n", sc));
@@ -507,35 +657,20 @@ uftdi_param(void *vsc, int portno, struc
default:
return EINVAL;
}
+ ratehi = 0;
break;
-
case UFTDI_TYPE_8U232AM:
- switch(t->c_ospeed) {
- case 300: rate = ftdi_8u232am_b300; break;
- case 600: rate = ftdi_8u232am_b600; break;
- case 1200: rate = ftdi_8u232am_b1200; break;
- case 2400: rate = ftdi_8u232am_b2400; break;
- case 4800: rate = ftdi_8u232am_b4800; break;
- case 9600: rate = ftdi_8u232am_b9600; break;
- case 19200: rate = ftdi_8u232am_b19200; break;
- case 38400: rate = ftdi_8u232am_b38400; break;
- case 57600: rate = ftdi_8u232am_b57600; break;
- case 115200: rate = ftdi_8u232am_b115200; break;
- case 230400: rate = ftdi_8u232am_b230400; break;
- case 460800: rate = ftdi_8u232am_b460800; break;
- case 921600: rate = ftdi_8u232am_b921600; break;
- default:
+ rerr = uftdi_encode_baudrate(sc, t->c_ospeed, &rate, &ratehi);
+ if (rerr != 0)
return EINVAL;
- }
break;
-
default:
return EINVAL;
}
req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
req.bRequest = FTDI_SIO_SET_BAUD_RATE;
USETW(req.wValue, rate);
- USETW(req.wIndex, portno);
+ USETW(req.wIndex, portno | ratehi);
USETW(req.wLength, 0);
DPRINTFN(2,("uftdi_param: reqtype=0x%02x req=0x%02x value=0x%04x "
"index=0x%04x len=%d\n", req.bmRequestType, req.bRequest,
Index: src/sys/dev/usb/uftdireg.h
diff -u src/sys/dev/usb/uftdireg.h:1.10 src/sys/dev/usb/uftdireg.h:1.11
--- src/sys/dev/usb/uftdireg.h:1.10 Sat Apr 23 10:15:32 2016
+++ src/sys/dev/usb/uftdireg.h Fri Sep 13 20:50:45 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: uftdireg.h,v 1.10 2016/04/23 10:15:32 skrll Exp $ */
+/* $NetBSD: uftdireg.h,v 1.11 2019/09/13 20:50:45 ryo Exp $ */
/*
* Definitions for the FTDI USB Single Port Serial Converter -
@@ -91,22 +91,6 @@ enum {
ftdi_sio_b115200 = 9
};
-enum {
- ftdi_8u232am_b300 = 0x2710,
- ftdi_8u232am_b600 = 0x1388,
- ftdi_8u232am_b1200 = 0x09c4,
- ftdi_8u232am_b2400 = 0x04e2,
- ftdi_8u232am_b4800 = 0x0271,
- ftdi_8u232am_b9600 = 0x4138,
- ftdi_8u232am_b19200 = 0x809c,
- ftdi_8u232am_b38400 = 0xc04e,
- ftdi_8u232am_b57600 = 0x0034,
- ftdi_8u232am_b115200 = 0x001a,
- ftdi_8u232am_b230400 = 0x000d,
- ftdi_8u232am_b460800 = 0x4006,
- ftdi_8u232am_b921600 = 0x8003
-};
-
/*
* BmRequestType: 0100 0000B
* bRequest: FTDI_SIO_SET_DATA
