@@ -1128,9 +1128,6 @@ static int img_i2c_init(struct img_i2c *i2c)
/* Fencing enabled by default. */
i2c->need_wr_rd_fence = true;
- bitrate_khz = i2c->bitrate / 1000;
- clk_khz = clk_get_rate(i2c->scb_clk) / 1000;
-
/* Determine what mode we're in from the bitrate */
timing = timings[0];
for (i = 0; i < ARRAY_SIZE(timings); i++) {
@@ -1139,6 +1136,17 @@ static int img_i2c_init(struct img_i2c *i2c)
break;
}
}
+ if (i2c->bitrate > timings[ARRAY_SIZE(timings) - 1].max_bitrate) {
+ dev_warn(i2c->adap.dev.parent,
+ "requested bitrate (%u) is higher than the max bitrate supported (%u)\n",
+ i2c->bitrate,
+ timings[ARRAY_SIZE(timings) - 1].max_bitrate);
+ timing = timings[ARRAY_SIZE(timings) - 1];
+ i2c->bitrate = timing.max_bitrate;
+ }
+
+ bitrate_khz = i2c->bitrate / 1000;
+ clk_khz = clk_get_rate(i2c->scb_clk) / 1000;
/* Find the prescale that would give us that inc (approx delay = 0) */
prescale = SCB_OPT_INC * clk_khz / (256 * 16 * bitrate_khz);
This is a note to let you know that I have just added a patch titled i2c: img-scb: verify support for requested bit rate to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt11. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 0cdd21011260ffa3830518cae0e6fd9b82a0a28d Mon Sep 17 00:00:00 2001 From: Sifan Naeem <sifan.naeem@imgtec.com> Date: Thu, 10 Sep 2015 15:50:07 +0100 Subject: i2c: img-scb: verify support for requested bit rate commit 58b0497dad1abbe389af83e3d7706be584cf3ba2 upstream. The requested bit rate can be outside the range supported by the driver. The maximum bit rate this driver supports at the moment is 400Khz. If the requested bit rate is larger than the maximum supported by the driver, set the bitrate to the maximum supported before bitrate_khz is calculated. Maximum speed supported by the driver can be increased to 1Mhz by adding support for "fast plus mode" in the future. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/i2c/busses/i2c-img-scb.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) -- 1.9.1