[src/trunk]: src/sys/arch/arm/rockchip rkiic: coalesce smbus-style writes int...

[tnn <tnn%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a7c2621a41e9
branches:  trunk
changeset: 965469:a7c2621a41e9
user:      tnn <tnn%NetBSD.org@localhost>
date:      Wed Sep 18 12:49:34 2019 +0000

description:
rkiic: coalesce smbus-style writes into a single transaction

There seems to be a hw controller bug. Split cmd/data writes caused corrupt
transfers, with junk bytes witten into the rk808 pmic registers.
This may have caused us to operate with out-of-spec core voltage.

diffstat:

 sys/arch/arm/rockchip/rk_i2c.c |  28 ++++++++++++----------------
 1 files changed, 12 insertions(+), 16 deletions(-)

diffs (74 lines):

diff -r f739a1548107 -r a7c2621a41e9 sys/arch/arm/rockchip/rk_i2c.c
--- a/sys/arch/arm/rockchip/rk_i2c.c    Wed Sep 18 10:42:44 2019 +0000
+++ b/sys/arch/arm/rockchip/rk_i2c.c    Wed Sep 18 12:49:34 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: rk_i2c.c,v 1.4 2018/09/02 10:07:17 jmcneill Exp $ */
+/* $NetBSD: rk_i2c.c,v 1.5 2019/09/18 12:49:34 tnn Exp $ */
 
 /*-
  * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -28,7 +28,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: rk_i2c.c,v 1.4 2018/09/02 10:07:17 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rk_i2c.c,v 1.5 2019/09/18 12:49:34 tnn Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -244,8 +244,8 @@
 }
 
 static int
-rk_i2c_write(struct rk_i2c_softc *sc, i2c_addr_t addr, const uint8_t *buf,
-    size_t buflen, int flags, bool send_start)
+rk_i2c_write(struct rk_i2c_softc *sc, i2c_addr_t addr, const uint8_t *cmd,
+    size_t cmdlen, const uint8_t *buf, size_t buflen, int flags, bool send_start)
 {
        union {
                uint8_t data8[32];
@@ -254,8 +254,10 @@
        uint32_t con;
        u_int mode;
        int error;
+       size_t len;
 
-       if (buflen > 31)
+       len = cmdlen + buflen;
+       if (len > 31)
                return EINVAL;
 
        mode = RKI2C_CON_I2C_MODE_TX;
@@ -267,10 +269,11 @@
 
        /* Transmit data. Slave address goes in the lower 8 bits of TXDATA0 */
        txdata.data8[0] = addr << 1;
-       memcpy(&txdata.data8[1], buf, buflen);
+       memcpy(&txdata.data8[1], cmd, cmdlen);
+       memcpy(&txdata.data8[1 + cmdlen], buf, buflen);
        bus_space_write_region_4(sc->sc_bst, sc->sc_bsh, RKI2C_TXDATA(0),
-           txdata.data32, howmany(buflen + 1, 4));
-       WR4(sc, RKI2C_MTXCNT, __SHIFTIN(buflen + 1, RKI2C_MTXCNT_MTXCNT));
+           txdata.data32, howmany(len + 1, 4));
+       WR4(sc, RKI2C_MTXCNT, __SHIFTIN(len + 1, RKI2C_MTXCNT_MTXCNT));
 
        if ((error = rk_i2c_wait(sc, RKI2C_IPD_MBTFIPD)) != 0)
                return error;
@@ -338,16 +341,9 @@
        if (I2C_OP_READ_P(op)) {
                error = rk_i2c_read(sc, addr, cmdbuf, cmdlen, buf, buflen, flags, send_start);
        } else {
-               if (cmdlen > 0) {
-                       error = rk_i2c_write(sc, addr, cmdbuf, cmdlen, flags, send_start);
-                       if (error != 0)
-                               goto done;
-                       send_start = false;
-               }
-               error = rk_i2c_write(sc, addr, buf, buflen, flags, send_start);
+               error = rk_i2c_write(sc, addr, cmdbuf, cmdlen, buf, buflen, flags, send_start);
        }
 
-done:
        if (error != 0 || I2C_OP_STOP_P(op))
                rk_i2c_stop(sc);