From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1chAEs-00008G-3k for barebox@lists.infradead.org; Fri, 24 Feb 2017 07:24:27 +0000 Date: Fri, 24 Feb 2017 08:24:04 +0100 From: Sascha Hauer Message-ID: <20170224072404.kuheslpettjdnuny@pengutronix.de> References: <20170223163450.6611-1-bst@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170223163450.6611-1-bst@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 1/2] i2c: mv64xxx: add software delays To: Bastian Stender Cc: barebox@lists.infradead.org On Thu, Feb 23, 2017 at 05:34:49PM +0100, Bastian Stender wrote: > As stated in Marvell's Functional Specifications in MV-S107021-U0 Rev. A > on page 420 ff. software delays are needed. "SW delay represent a delay > of at least 2 internal clock cycles". These delays are hereby > implemented. > > The original kernel driver compensates the needed software delays with > the time the interrupts take. > > Signed-off-by: Bastian Stender Applied, thanks Sascha > --- > drivers/i2c/busses/i2c-mv64xxx.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c > index 9b9e6c953f..45d5a2b6dc 100644 > --- a/drivers/i2c/busses/i2c-mv64xxx.c > +++ b/drivers/i2c/busses/i2c-mv64xxx.c > @@ -270,6 +270,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) > } > /* FALLTHRU */ > case STATUS_MAST_RD_DATA_ACK: /* 0x50 */ > + udelay(2); > if (status != STATUS_MAST_RD_DATA_ACK) > drv_data->action = ACTION_CONTINUE; > else { > @@ -280,6 +281,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) > > if (drv_data->bytes_left == 1) > drv_data->cntl_bits &= ~REG_CONTROL_ACK; > + udelay(2); > break; > > case STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ > @@ -318,6 +320,8 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) > mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs); > mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_START, > drv_data->reg_offsets.control); > + > + udelay(2); > } > > static void > @@ -333,7 +337,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) > mv64xxx_i2c_send_start(drv_data); > > if (drv_data->errata_delay) > - udelay(5); > + udelay(3); > > /* > * We're never at the start of the message here, and by this > @@ -349,6 +353,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) > break; > > case ACTION_SEND_ADDR_1: > + udelay(2); > mv64xxx_write(drv_data, drv_data->addr1, > drv_data->reg_offsets.data); > mv64xxx_write(drv_data, drv_data->cntl_bits, > @@ -360,9 +365,11 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) > drv_data->reg_offsets.data); > mv64xxx_write(drv_data, drv_data->cntl_bits, > drv_data->reg_offsets.control); > + udelay(2); > break; > > case ACTION_SEND_DATA: > + udelay(2); > mv64xxx_write(drv_data, drv_data->msg->buf[drv_data->byte_posn++], > drv_data->reg_offsets.data); > mv64xxx_write(drv_data, drv_data->cntl_bits, > @@ -383,8 +390,9 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) > mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_STOP, > drv_data->reg_offsets.control); > drv_data->block = false; > + udelay(2); > if (drv_data->errata_delay) > - udelay(5); > + udelay(3); > > break; > > -- > 2.11.0 > > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox