From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56456) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gRR1Z-0002gU-7e for qemu-devel@nongnu.org; Mon, 26 Nov 2018 19:14:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gRR1V-0002V5-QH for qemu-devel@nongnu.org; Mon, 26 Nov 2018 19:14:45 -0500 Received: from mail-ot1-x341.google.com ([2607:f8b0:4864:20::341]:36014) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gRR1V-0002Ux-KY for qemu-devel@nongnu.org; Mon, 26 Nov 2018 19:14:41 -0500 Received: by mail-ot1-x341.google.com with SMTP id k98so18488755otk.3 for ; Mon, 26 Nov 2018 16:14:41 -0800 (PST) Sender: Corey Minyard Reply-To: minyard@acm.org References: <20181126200435.23408-1-minyard@acm.org> <20181126200435.23408-3-minyard@acm.org> From: Corey Minyard Message-ID: Date: Mon, 26 Nov 2018 18:14:37 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-GB Subject: Re: [Qemu-devel] [PATCH v3 02/16] i2c: have I2C receive operation return uint8_t List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Peter Maydell Cc: Paolo Bonzini , "Michael S . Tsirkin" , Corey Minyard On 11/26/18 2:23 PM, Philippe Mathieu-Daudé wrote: > Hi Corey, > > On 26/11/18 21:04, minyard@acm.org wrote: >> From: Corey Minyard >> >> It is never supposed to fail and cannot return an error, so just >> have it return the proper type. Have it return 0xff on nothing >> available, since that's what would happen on a real bus. >> >> Signed-off-by: Corey Minyard >> Reviewed-by: Peter Maydell >> --- >> hw/arm/pxa2xx.c | 2 +- >> hw/arm/tosa.c | 4 ++-- >> hw/arm/z2.c | 2 +- >> hw/audio/wm8750.c | 2 +- >> hw/display/sii9022.c | 2 +- >> hw/display/ssd0303.c | 4 ++-- >> hw/gpio/max7310.c | 2 +- >> hw/i2c/core.c | 32 +++++++++++++------------------- >> hw/i2c/i2c-ddc.c | 2 +- >> hw/i2c/smbus_slave.c | 4 ++-- >> hw/input/lm832x.c | 2 +- >> hw/misc/pca9552.c | 2 +- >> hw/misc/tmp105.c | 2 +- >> hw/misc/tmp421.c | 2 +- >> hw/nvram/eeprom_at24c.c | 4 ++-- >> hw/timer/ds1338.c | 2 +- >> hw/timer/m41t80.c | 2 +- >> hw/timer/twl92230.c | 2 +- >> include/hw/i2c/i2c.h | 7 +++---- >> 19 files changed, 37 insertions(+), 44 deletions(-) >> >> diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c >> index f598a1c053..3d7c88910e 100644 >> --- a/hw/arm/pxa2xx.c >> +++ b/hw/arm/pxa2xx.c >> @@ -1286,7 +1286,7 @@ static int pxa2xx_i2c_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int pxa2xx_i2c_rx(I2CSlave *i2c) >> +static uint8_t pxa2xx_i2c_rx(I2CSlave *i2c) >> { >> PXA2xxI2CSlaveState *slave = PXA2XX_I2C_SLAVE(i2c); >> PXA2xxI2CState *s = slave->host; >> diff --git a/hw/arm/tosa.c b/hw/arm/tosa.c >> index 7a925fa5e6..eef9d427e7 100644 >> --- a/hw/arm/tosa.c >> +++ b/hw/arm/tosa.c >> @@ -197,10 +197,10 @@ static int tosa_dac_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int tosa_dac_recv(I2CSlave *s) >> +static uint8_t tosa_dac_recv(I2CSlave *s) >> { >> printf("%s: recv not supported!!!\n", __func__); >> - return -1; >> + return 0xff; >> } >> >> static void tosa_tg_init(PXA2xxState *cpu) >> diff --git a/hw/arm/z2.c b/hw/arm/z2.c >> index 697a822f1e..6f18d924df 100644 >> --- a/hw/arm/z2.c >> +++ b/hw/arm/z2.c >> @@ -243,7 +243,7 @@ static int aer915_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int aer915_recv(I2CSlave *slave) >> +static uint8_t aer915_recv(I2CSlave *slave) >> { >> AER915State *s = AER915(slave); >> int retval = 0x00; >> diff --git a/hw/audio/wm8750.c b/hw/audio/wm8750.c >> index f4aa838f62..169b006ade 100644 >> --- a/hw/audio/wm8750.c >> +++ b/hw/audio/wm8750.c >> @@ -561,7 +561,7 @@ static int wm8750_tx(I2CSlave *i2c, uint8_t data) >> return 0; >> } >> >> -static int wm8750_rx(I2CSlave *i2c) >> +static uint8_t wm8750_rx(I2CSlave *i2c) >> { >> return 0x00; >> } >> diff --git a/hw/display/sii9022.c b/hw/display/sii9022.c >> index eaf11a6e7b..9994385c35 100644 >> --- a/hw/display/sii9022.c >> +++ b/hw/display/sii9022.c >> @@ -79,7 +79,7 @@ static int sii9022_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int sii9022_rx(I2CSlave *i2c) >> +static uint8_t sii9022_rx(I2CSlave *i2c) >> { >> sii9022_state *s = SII9022(i2c); >> uint8_t res = 0x00; >> diff --git a/hw/display/ssd0303.c b/hw/display/ssd0303.c >> index eb90ba26be..8edf34986c 100644 >> --- a/hw/display/ssd0303.c >> +++ b/hw/display/ssd0303.c >> @@ -62,10 +62,10 @@ typedef struct { >> uint8_t framebuffer[132*8]; >> } ssd0303_state; >> >> -static int ssd0303_recv(I2CSlave *i2c) >> +static uint8_t ssd0303_recv(I2CSlave *i2c) >> { >> BADF("Reads not implemented\n"); >> - return -1; >> + return 0xff; >> } >> >> static int ssd0303_send(I2CSlave *i2c, uint8_t data) >> diff --git a/hw/gpio/max7310.c b/hw/gpio/max7310.c >> index a560e3afd2..f35a930276 100644 >> --- a/hw/gpio/max7310.c >> +++ b/hw/gpio/max7310.c >> @@ -39,7 +39,7 @@ static void max7310_reset(DeviceState *dev) >> s->command = 0x00; >> } >> >> -static int max7310_rx(I2CSlave *i2c) >> +static uint8_t max7310_rx(I2CSlave *i2c) >> { >> MAX7310State *s = MAX7310(i2c); >> >> diff --git a/hw/i2c/core.c b/hw/i2c/core.c >> index b54725985a..15237ad073 100644 >> --- a/hw/i2c/core.c >> +++ b/hw/i2c/core.c >> @@ -191,23 +191,17 @@ int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send) > i2c_send_recv() could benefit the same improvement. > I thought some about that, but the send function has to be able to return -1 for a NACK.  It would be nice to have separate send and recv functions, but several host devices use i2c_send_recv() directly. >> } >> return ret ? -1 : 0; >> } else { >> - if ((QLIST_EMPTY(&bus->current_devs)) || (bus->broadcast)) { >> - return -1; >> - } >> - >> - sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt); >> - if (sc->recv) { >> - s = QLIST_FIRST(&bus->current_devs)->elt; >> - ret = sc->recv(s); >> - trace_i2c_recv(s->address, ret); >> - if (ret < 0) { >> - return ret; >> - } else { >> - *data = ret; >> - return 0; >> + ret = 0xff; >> + if (!QLIST_EMPTY(&bus->current_devs) && !bus->broadcast) { >> + sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt); >> + if (sc->recv) { >> + s = QLIST_FIRST(&bus->current_devs)->elt; >> + ret = sc->recv(s); >> + trace_i2c_recv(s->address, ret); >> } >> } >> - return -1; >> + *data = ret; >> + return 0; >> } >> } >> >> @@ -216,12 +210,12 @@ int i2c_send(I2CBus *bus, uint8_t data) >> return i2c_send_recv(bus, &data, true); >> } >> >> -int i2c_recv(I2CBus *bus) >> +uint8_t i2c_recv(I2CBus *bus) >> { >> - uint8_t data; >> - int ret = i2c_send_recv(bus, &data, false); >> + uint8_t data = 0xff; >> >> - return ret < 0 ? ret : data; >> + i2c_send_recv(bus, &data, false); >> + return data; >> } >> >> void i2c_nack(I2CBus *bus) >> diff --git a/hw/i2c/i2c-ddc.c b/hw/i2c/i2c-ddc.c >> index be34fe072c..95325358db 100644 >> --- a/hw/i2c/i2c-ddc.c >> +++ b/hw/i2c/i2c-ddc.c >> @@ -51,7 +51,7 @@ static int i2c_ddc_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int i2c_ddc_rx(I2CSlave *i2c) >> +static uint8_t i2c_ddc_rx(I2CSlave *i2c) >> { >> I2CDDCState *s = I2CDDC(i2c); >> >> diff --git a/hw/i2c/smbus_slave.c b/hw/i2c/smbus_slave.c >> index 1e734752d7..549e7ae933 100644 >> --- a/hw/i2c/smbus_slave.c >> +++ b/hw/i2c/smbus_slave.c >> @@ -156,11 +156,11 @@ static int smbus_i2c_event(I2CSlave *s, enum i2c_event event) >> return 0; >> } >> >> -static int smbus_i2c_recv(I2CSlave *s) >> +static uint8_t smbus_i2c_recv(I2CSlave *s) >> { >> SMBusDevice *dev = SMBUS_DEVICE(s); >> SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev); >> - int ret; >> + uint8_t ret; >> >> switch (dev->mode) { >> case SMBUS_RECV_BYTE: >> diff --git a/hw/input/lm832x.c b/hw/input/lm832x.c >> index 74da30d9ca..9ae037953d 100644 >> --- a/hw/input/lm832x.c >> +++ b/hw/input/lm832x.c >> @@ -401,7 +401,7 @@ static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int lm_i2c_rx(I2CSlave *i2c) >> +static uint8_t lm_i2c_rx(I2CSlave *i2c) >> { >> LM823KbdState *s = LM8323(i2c); >> >> diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c >> index 9775d5274a..7325d3f287 100644 >> --- a/hw/misc/pca9552.c >> +++ b/hw/misc/pca9552.c >> @@ -115,7 +115,7 @@ static void pca9552_autoinc(PCA9552State *s) >> } >> } >> >> -static int pca9552_recv(I2CSlave *i2c) >> +static uint8_t pca9552_recv(I2CSlave *i2c) >> { >> PCA9552State *s = PCA9552(i2c); >> uint8_t ret; >> diff --git a/hw/misc/tmp105.c b/hw/misc/tmp105.c >> index 0918f3a6ea..a4cae665b7 100644 >> --- a/hw/misc/tmp105.c >> +++ b/hw/misc/tmp105.c >> @@ -147,7 +147,7 @@ static void tmp105_write(TMP105State *s) >> } >> } >> >> -static int tmp105_rx(I2CSlave *i2c) >> +static uint8_t tmp105_rx(I2CSlave *i2c) >> { >> TMP105State *s = TMP105(i2c); >> >> diff --git a/hw/misc/tmp421.c b/hw/misc/tmp421.c >> index c234044305..a75eb994a8 100644 >> --- a/hw/misc/tmp421.c >> +++ b/hw/misc/tmp421.c >> @@ -249,7 +249,7 @@ static void tmp421_write(TMP421State *s) >> } >> } >> >> -static int tmp421_rx(I2CSlave *i2c) >> +static uint8_t tmp421_rx(I2CSlave *i2c) >> { >> TMP421State *s = TMP421(i2c); >> >> diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c >> index 27cd01e615..d1456dafbd 100644 >> --- a/hw/nvram/eeprom_at24c.c >> +++ b/hw/nvram/eeprom_at24c.c >> @@ -74,10 +74,10 @@ int at24c_eeprom_event(I2CSlave *s, enum i2c_event event) >> } >> >> static >> -int at24c_eeprom_recv(I2CSlave *s) >> +uint8_t at24c_eeprom_recv(I2CSlave *s) >> { >> EEPROMState *ee = AT24C_EE(s); >> - int ret; >> + uint8_t ret; >> >> ret = ee->mem[ee->cur]; >> >> diff --git a/hw/timer/ds1338.c b/hw/timer/ds1338.c >> index 3849b74a68..03da75486b 100644 >> --- a/hw/timer/ds1338.c >> +++ b/hw/timer/ds1338.c >> @@ -117,7 +117,7 @@ static int ds1338_event(I2CSlave *i2c, enum i2c_event event) >> return 0; >> } >> >> -static int ds1338_recv(I2CSlave *i2c) >> +static uint8_t ds1338_recv(I2CSlave *i2c) >> { >> DS1338State *s = DS1338(i2c); >> uint8_t res; >> diff --git a/hw/timer/m41t80.c b/hw/timer/m41t80.c >> index 734d7d95fc..c45b9297d8 100644 >> --- a/hw/timer/m41t80.c >> +++ b/hw/timer/m41t80.c >> @@ -40,7 +40,7 @@ static int m41t80_send(I2CSlave *i2c, uint8_t data) >> return 0; >> } >> >> -static int m41t80_recv(I2CSlave *i2c) >> +static uint8_t m41t80_recv(I2CSlave *i2c) >> { >> M41t80State *s = M41T80(i2c); >> struct tm now; >> diff --git a/hw/timer/twl92230.c b/hw/timer/twl92230.c >> index 3b43b46199..659b216dca 100644 >> --- a/hw/timer/twl92230.c >> +++ b/hw/timer/twl92230.c >> @@ -737,7 +737,7 @@ static int menelaus_tx(I2CSlave *i2c, uint8_t data) >> return 0; >> } >> >> -static int menelaus_rx(I2CSlave *i2c) >> +static uint8_t menelaus_rx(I2CSlave *i2c) >> { >> MenelausState *s = TWL92230(i2c); >> >> diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h >> index 5dc166158b..75c5bd638b 100644 >> --- a/include/hw/i2c/i2c.h >> +++ b/include/hw/i2c/i2c.h >> @@ -33,10 +33,9 @@ typedef struct I2CSlaveClass { >> >> /* >> * Slave to master. This cannot fail, the device should always >> - * return something here. Negative values probably result in 0xff >> - * and a possible log from the driver, and shouldn't be used. >> + * return something here. > Maybe use simple comment as "Master receives the data sent by the Slave" I'm not sure I follow.  I think it's important to say that the device must return something, Are you talking about the "Slave to master" part? Thanks, -corey >> */ >> - int (*recv)(I2CSlave *s); >> + uint8_t (*recv)(I2CSlave *s); >> >> /* >> * Notify the slave of a bus state change. For start event, >> @@ -78,7 +77,7 @@ void i2c_end_transfer(I2CBus *bus); >> void i2c_nack(I2CBus *bus); >> int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send); >> int i2c_send(I2CBus *bus, uint8_t data); >> -int i2c_recv(I2CBus *bus); >> +uint8_t i2c_recv(I2CBus *bus); >> >> DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr); >> > Reviewed-by: Philippe Mathieu-Daudé > Tested-by: Philippe Mathieu-Daudé >