From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:37283) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1goBEF-0003b9-Rc for qemu-devel@nongnu.org; Mon, 28 Jan 2019 13:01:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1goB7r-0005WU-Sb for qemu-devel@nongnu.org; Mon, 28 Jan 2019 12:55:30 -0500 Received: from mail-io1-xd41.google.com ([2607:f8b0:4864:20::d41]:37734) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1goB7r-0005WA-Np for qemu-devel@nongnu.org; Mon, 28 Jan 2019 12:55:15 -0500 Received: by mail-io1-xd41.google.com with SMTP id g8so14245248iok.4 for ; Mon, 28 Jan 2019 09:55:15 -0800 (PST) Sender: Corey Minyard From: minyard@acm.org Date: Mon, 28 Jan 2019 11:54:44 -0600 Message-Id: <20190128175458.27255-6-minyard@acm.org> In-Reply-To: <20190128175458.27255-1-minyard@acm.org> References: <20190128175458.27255-1-minyard@acm.org> Subject: [Qemu-devel] [PATCH v4 05/19] i2c:smbus: Correct the working of quick commands List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, "Dr . David Alan Gilbert" Cc: Paolo Bonzini , "Michael S . Tsirkin" , Corey Minyard , Peter Maydell , Corey Minyard From: Corey Minyard The logic of handling quick SMBus commands was wrong. If you get a finish event with no data, that's a quick command. Document the quick command while we are at it. Signed-off-by: Corey Minyard --- hw/i2c/smbus_slave.c | 35 +++++++++++++++++++---------------- include/hw/i2c/smbus_slave.h | 5 +++++ 2 files changed, 24 insertions(+), 16 deletions(-) diff --git a/hw/i2c/smbus_slave.c b/hw/i2c/smbus_slave.c index 6e4d542f51..6a89a286e3 100644 --- a/hw/i2c/smbus_slave.c +++ b/hw/i2c/smbus_slave.c @@ -54,9 +54,7 @@ static void smbus_do_write(SMBusDevice *dev) { SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev); - if (dev->data_len == 0) { - smbus_do_quick_cmd(dev, 0); - } else if (dev->data_len == 1) { + if (dev->data_len == 1) { DPRINTF("Send Byte\n"); if (sc->send_byte) { sc->send_byte(dev, dev->data_buf[0]); @@ -120,19 +118,24 @@ static int smbus_i2c_event(I2CSlave *s, enum i2c_event event) break; case I2C_FINISH: - switch (dev->mode) { - case SMBUS_WRITE_DATA: - smbus_do_write(dev); - break; - case SMBUS_RECV_BYTE: - smbus_do_quick_cmd(dev, 1); - break; - case SMBUS_READ_DATA: - BADF("Unexpected stop during receive\n"); - break; - default: - /* Nothing to do. */ - break; + if (dev->data_len == 0) { + if (dev->mode == SMBUS_WRITE_DATA || dev->mode == SMBUS_READ_DATA) { + smbus_do_quick_cmd(dev, dev->mode == SMBUS_READ_DATA); + } + } else { + switch (dev->mode) { + case SMBUS_WRITE_DATA: + smbus_do_write(dev); + break; + + case SMBUS_READ_DATA: + BADF("Unexpected stop during receive\n"); + break; + + default: + /* Nothing to do. */ + break; + } } dev->mode = SMBUS_IDLE; dev->data_len = 0; diff --git a/include/hw/i2c/smbus_slave.h b/include/hw/i2c/smbus_slave.h index 46b8948f0f..5ef1c72ad0 100644 --- a/include/hw/i2c/smbus_slave.h +++ b/include/hw/i2c/smbus_slave.h @@ -40,6 +40,11 @@ typedef struct SMBusDevice SMBusDevice; typedef struct SMBusDeviceClass { I2CSlaveClass parent_class; + + /* + * An operation with no data, special in SMBus. + * This may be NULL, quick commands are ignore in that case. + */ void (*quick_cmd)(SMBusDevice *dev, uint8_t read); void (*send_byte)(SMBusDevice *dev, uint8_t val); uint8_t (*receive_byte)(SMBusDevice *dev); -- 2.17.1