From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 4/7] i2c: omap: in case of VERSION_2 read IRQSTATUS_RAW but write to IRQSTATUS
Date: Thu, 25 Oct 2012 18:23:57 +0530 [thread overview]
Message-ID: <50893665.60604@ti.com> (raw)
In-Reply-To: <1351167915-15079-5-git-send-email-balbi@ti.com>
On Thursday 25 October 2012 05:55 PM, Felipe Balbi wrote:
> on OMAP4+ we want to read IRQSTATUS_RAW register,
> instead of IRQSTATUS. The reason being that IRQSTATUS
> will only contain the bits which were enabled on
> IRQENABLE_SET and that will break when we need to
> poll for a certain bit which wasn't enabled as an
> IRQ source.
>
> One such case is after we finish converting to
> deferred stop bit, we will have to poll for ARDY
> bit before returning control for the client driver
> in order to prevent us from trying to start a
> transfer on a bus which is already busy.
>
> Note, however, that omap-i2c.c needs a big rework
> on register definition and register access. Such
> work will be done in a separate series of patches.
>
> Cc: Benoit Cousson <b-cousson@ti•com>
> Signed-off-by: Felipe Balbi <balbi@ti•com>
> ---
> drivers/i2c/busses/i2c-omap.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index b004126..20f9ad6 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -271,8 +271,18 @@ static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
>
> static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
> {
> - return __raw_readw(i2c_dev->base +
> + /* if we are OMAP_I2C_IP_VERSION_2, we need to read from
> + * IRQSTATUS_RAW, but write to IRQSTATUS
> + */
> + if ((i2c_dev->dtrev == OMAP_I2C_IP_VERSION_2) &&
> + (reg == OMAP_I2C_STAT_REG)) {
Doing this check on every I2C register read seems to
expensive to me. Can you not sort this in init with some offset
which can be 0 or non zero ? Sorry in case this is already dicussed.
regards
santosh
next prev parent reply other threads:[~2012-10-25 12:53 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-22 9:46 [PATCH 0/8] I2C patches for v3.8 merge window Felipe Balbi
2012-10-22 9:46 ` [PATCH 1/8] i2c: omap: no need to access platform_device Felipe Balbi
2012-10-22 9:46 ` [PATCH 2/8] i2c: omap: reorder exit path of omap_i2c_xfer_msg() Felipe Balbi
2012-10-25 11:40 ` Shubhrajyoti Datta
2012-10-25 12:01 ` Felipe Balbi
2012-10-22 9:46 ` [PATCH 3/8] i2c: omap: fix error checking Felipe Balbi
2012-10-24 14:41 ` Michael Trimarchi
2012-10-25 10:10 ` Felipe Balbi
2012-10-25 10:33 ` Michael Trimarchi
2012-10-25 10:48 ` Felipe Balbi
2012-10-22 9:46 ` [PATCH 4/8] i2c: omap: also complete() when stat becomes zero Felipe Balbi
2012-10-22 9:46 ` [PATCH 5/8] i2c: omap: introduce and use OMAP_I2C_IP_VERSION_3 Felipe Balbi
2012-10-22 12:27 ` Benoit Cousson
2012-10-22 12:28 ` Felipe Balbi
2012-10-22 13:05 ` Benoit Cousson
2012-10-22 13:09 ` Felipe Balbi
2012-10-22 13:18 ` [PATCH v2 5/8] i2c: omap: in case of VERSION_2 read IRQSTATUS_RAW but write to IRQSTATUS Felipe Balbi
2012-10-22 9:46 ` [PATCH 6/8] i2c: omap: wait for transfer completion before sending STP bit Felipe Balbi
2012-10-22 9:46 ` [PATCH 7/8] i2c: add 'transferred' field to struct i2c_msg Felipe Balbi
2012-10-25 12:57 ` Jean Delvare
2012-10-25 13:14 ` Russell King - ARM Linux
2012-10-25 13:42 ` Jean Delvare
2012-10-25 13:46 ` Russell King - ARM Linux
2012-10-25 13:56 ` Jean Delvare
2012-10-25 14:18 ` Russell King - ARM Linux
2012-10-27 14:32 ` Jean Delvare
2012-10-27 16:40 ` Al Viro
2012-10-27 17:02 ` Al Viro
2012-10-27 17:10 ` Al Viro
2012-10-27 19:03 ` Jean Delvare
2012-10-27 17:25 ` Russell King - ARM Linux
2012-10-22 9:46 ` [PATCH 8/8] i2c: omap: implement handling for 'transferred' bytes Felipe Balbi
2012-10-22 13:30 ` [PATCH 0/8] I2C patches for v3.8 merge window Felipe Balbi
2012-10-22 14:06 ` Shubhrajyoti Datta
2012-10-22 14:06 ` Felipe Balbi
2012-10-22 15:02 ` Shubhrajyoti
2012-11-14 16:58 ` Wolfram Sang
2012-10-25 12:25 ` [PATCH v2 0/7] " Felipe Balbi
2012-10-25 12:25 ` [PATCH v2 1/7] i2c: omap: no need to access platform_device Felipe Balbi
2012-10-25 12:41 ` Santosh Shilimkar
2012-10-25 12:25 ` [PATCH v2 2/7] i2c: omap: reorder exit path of omap_i2c_xfer_msg() Felipe Balbi
2012-10-25 12:42 ` Santosh Shilimkar
2012-10-25 12:40 ` Felipe Balbi
2012-10-25 12:53 ` Lothar Waßmann
2012-10-25 12:25 ` [PATCH v2 3/7] i2c: omap: also complete() when stat becomes zero Felipe Balbi
2012-10-25 12:43 ` Santosh Shilimkar
2012-10-25 12:39 ` Felipe Balbi
2012-10-25 12:25 ` [PATCH v2 4/7] i2c: omap: in case of VERSION_2 read IRQSTATUS_RAW but write to IRQSTATUS Felipe Balbi
2012-10-25 12:53 ` Santosh Shilimkar [this message]
2012-10-25 12:52 ` Felipe Balbi
2012-10-25 13:06 ` Santosh Shilimkar
2012-10-25 12:25 ` [PATCH v2 5/7] i2c: omap: wait for transfer completion before sending STP bit Felipe Balbi
2012-10-25 12:32 ` Felipe Balbi
2012-10-25 12:34 ` [PATCH v3 " Felipe Balbi
2012-10-25 13:01 ` [PATCH v2 " Santosh Shilimkar
2012-10-25 14:15 ` Felipe Balbi
2012-10-25 12:25 ` [PATCH v2 6/7] i2c: add 'transferred' field to struct i2c_msg Felipe Balbi
2012-10-25 12:25 ` [PATCH v2 7/7] i2c: omap: implement handling for 'transferred' bytes Felipe Balbi
2012-10-27 18:55 ` Paul Walmsley
2012-11-05 8:10 ` [PATCH v2 0/7] I2C patches for v3.8 merge window Felipe Balbi
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