From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Christophe PLAGNIOL-VILLARD Subject: Re: [PATCH 1/5] i2c: at91: add new fixes for some TWI ip versions Date: Wed, 22 Aug 2012 14:32:47 +0200 Message-ID: <20120822123247.GD7456@game.jcrosoft.org> References: <1345559345-13988-1-git-send-email-ludovic.desroches@atmel.com> <1345559345-13988-2-git-send-email-ludovic.desroches@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1345559345-13988-2-git-send-email-ludovic.desroches@atmel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: ludovic.desroches@atmel.com Cc: n.voss@weinmann.de, nicolas.ferre@atmel.com, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-i2c@vger.kernel.org On 16:29 Tue 21 Aug , ludovic.desroches@atmel.com wrote: > From: Ludovic Desroches > > The at91sam9261 TWI ip version requires also some fixes. The id_entry > field from the platform device structure has been replaced by the use > of cpu_is_xxx function to determine when to use these fixes. > > Signed-off-by: Ludovic Desroches > --- > arch/arm/mach-at91/at91rm9200_devices.c | 9 ------- > drivers/i2c/busses/i2c-at91.c | 42 +++++++++++++++++++-------------- > 2 files changed, 24 insertions(+), 27 deletions(-) > > diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c > index 2b9b493..e6b7d05 100644 > --- a/arch/arm/mach-at91/at91rm9200_devices.c > +++ b/arch/arm/mach-at91/at91rm9200_devices.c > @@ -494,18 +494,9 @@ static struct resource twi_resources[] = { > }, > }; > > -static const struct platform_device_id twi_id = { > - /* > - * driver_data is "1" for hardware with ckdiv upper limit == 5 > - * (AT91RM9200 erratum 22), "0" for twi modules without this bug > - */ > - .driver_data = 1, > -}; > - > static struct platform_device at91rm9200_twi_device = { > .name = "at91_i2c", > .id = -1, > - .id_entry = &twi_id, > .resource = twi_resources, > .num_resources = ARRAY_SIZE(twi_resources), > }; > diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c > index b1cb780..4599522 100644 > --- a/drivers/i2c/busses/i2c-at91.c > +++ b/drivers/i2c/busses/i2c-at91.c > @@ -27,6 +27,8 @@ > #include > #include > > +#include > + > #define TWI_CLK_HZ 100000 /* max 400 Kbits/s */ > #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ > > @@ -72,7 +74,6 @@ struct at91_twi_dev { > int irq; > unsigned transfer_status; > struct i2c_adapter adapter; > - bool is_rm9200; > unsigned twi_cwgr_reg; > }; > > @@ -111,20 +112,28 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev) > */ > static void __devinit at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) > { > - const int offset = dev->is_rm9200 ? 3 : 4; > - const int div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk), > - 2 * twi_clk) - offset); > - int ckdiv = fls(div >> 8); > - int cdiv = div >> ckdiv; > - > - if (dev->is_rm9200 && (ckdiv > 5)) { > - dev_warn(dev->dev, "AT91RM9200 erratum 22: using ckdiv = 5.\n"); > - ckdiv = 5; > - cdiv = 255; > - } else if (ckdiv > 7) { > - dev_warn(dev->dev, "%d exceeds 3 bits for ckdiv, limiting.\n", > - ckdiv); > - ckdiv = 7; > + int offset, div, max_ckdiv, ckdiv, cdiv; > + > + if (cpu_is_at91rm9200()) { > + offset = 3; > + max_ckdiv = 5; > + } else if (cpu_is_at91sam9261()) { > + offset = 4; > + max_ckdiv = 5; > + } else { > + offset = 4; > + max_ckdiv = 7; > + } can you read this from the IP version? I do not like the cpu_is outside of the mach-at91 Best Regards, J.