From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH 3/5] i2c: at91: add support for digital filtering Date: Thu, 20 Jun 2019 10:27:36 +0200 Message-ID: <20190620082736.GS23549@piout.net> References: <1561014676-22446-1-git-send-email-eugen.hristev@microchip.com> <1561014676-22446-3-git-send-email-eugen.hristev@microchip.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1561014676-22446-3-git-send-email-eugen.hristev@microchip.com> Sender: linux-kernel-owner@vger.kernel.org To: Eugen.Hristev@microchip.com Cc: robh+dt@kernel.org, mark.rutland@arm.com, Nicolas.Ferre@microchip.com, Ludovic.Desroches@microchip.com, wsa@the-dreams.de, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-i2c@vger.kernel.org On 20/06/2019 07:16:13+0000, Eugen.Hristev@microchip.com wrote: > From: Eugen Hristev > > Add new platform data support for digital filtering for i2c. > The sama5d4, sama5d2 and sam9x60 support this feature. > > Signed-off-by: Eugen Hristev > --- > drivers/i2c/busses/i2c-at91-core.c | 9 +++++++++ > drivers/i2c/busses/i2c-at91-master.c | 6 ++++++ > drivers/i2c/busses/i2c-at91.h | 4 ++++ > 3 files changed, 19 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c > index a663a7a..62610af 100644 > --- a/drivers/i2c/busses/i2c-at91-core.c > +++ b/drivers/i2c/busses/i2c-at91-core.c > @@ -68,6 +68,7 @@ static struct at91_twi_pdata at91rm9200_config = { > .has_unre_flag = true, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, As false is the default value, may we should avoid setting it explicitly to keep the file size manageable. > }; > > static struct at91_twi_pdata at91sam9261_config = { > @@ -76,6 +77,7 @@ static struct at91_twi_pdata at91sam9261_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, > }; > > static struct at91_twi_pdata at91sam9260_config = { > @@ -84,6 +86,7 @@ static struct at91_twi_pdata at91sam9260_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, > }; > > static struct at91_twi_pdata at91sam9g20_config = { > @@ -92,6 +95,7 @@ static struct at91_twi_pdata at91sam9g20_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, > }; > > static struct at91_twi_pdata at91sam9g10_config = { > @@ -100,6 +104,7 @@ static struct at91_twi_pdata at91sam9g10_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, > }; > > static const struct platform_device_id at91_twi_devtypes[] = { > @@ -130,6 +135,7 @@ static struct at91_twi_pdata at91sam9x5_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = false, > + .has_dig_filtr = false, > }; > > static struct at91_twi_pdata sama5d4_config = { > @@ -138,6 +144,7 @@ static struct at91_twi_pdata sama5d4_config = { > .has_unre_flag = false, > .has_alt_cmd = false, > .has_hold_field = true, > + .has_dig_filtr = true, > }; > > static struct at91_twi_pdata sama5d2_config = { > @@ -146,6 +153,7 @@ static struct at91_twi_pdata sama5d2_config = { > .has_unre_flag = true, > .has_alt_cmd = true, > .has_hold_field = true, > + .has_dig_filtr = true, > }; > > static struct at91_twi_pdata sam9x60_config = { > @@ -154,6 +162,7 @@ static struct at91_twi_pdata sam9x60_config = { > .has_unre_flag = true, > .has_alt_cmd = true, > .has_hold_field = true, > + .has_dig_filtr = true, > }; > > static const struct of_device_id atmel_twi_dt_ids[] = { > diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c > index e87232f..366e90f 100644 > --- a/drivers/i2c/busses/i2c-at91-master.c > +++ b/drivers/i2c/busses/i2c-at91-master.c > @@ -31,12 +31,18 @@ > > void at91_init_twi_bus_master(struct at91_twi_dev *dev) > { > + struct at91_twi_pdata *pdata = dev->pdata; > + > /* FIFO should be enabled immediately after the software reset */ > if (dev->fifo_size) > at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN); > at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN); > at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS); > at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg); > + > + /* enable digital filter */ > + if (pdata->has_dig_filtr) > + at91_twi_write(dev, AT91_TWI_FILTR, AT91_TWI_FILTR_FILT); You are enabling all those filtering features by default which mean that if we ever need to handle them using DT, the property will be a disabling one instead of a more logical enabling one. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com