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From: petr.cvek@tul•cz (Petr Cvek)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] Add support for SCCB devices into PXA27x I2C controller
Date: Sat, 22 Nov 2014 23:52:07 +0100	[thread overview]
Message-ID: <54711397.9060601@tul.cz> (raw)

Add support for SCCB devices into PXA27x I2C controller.

Fix generated START but no STOP for message without I2C_M_NOSTART flag. 
Add support for I2C_M_IGNORE_NAK flag.

Signed-off-by: Petr Cvek <petr.cvek@tul•cz>
---
  drivers/i2c/busses/i2c-pxa.c | 22 ++++++++++++++++------
  1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index be671f7..adad044 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -885,7 +885,14 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c 
*i2c, u32 isr)
          return; /* ignore */
      }

-    if (isr & ISR_BED) {
+    /*
+     * Ignore NAK when flag I2C_M_IGNORE_NAK is present,
+     * this enables use of SCCB devices
+     */
+    if ((isr & ISR_BED) &&
+        (!((i2c->msg->flags & I2C_M_IGNORE_NAK) &&
+            (isr & ISR_ACKNAK)))) {
+
          int ret = BUS_ERROR;

          /*
@@ -919,12 +926,15 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c 
*i2c, u32 isr)
          icr |= ICR_ALDIE | ICR_TB;

          /*
-         * If this is the last byte of the last message, send
-         * a STOP.
+         * If this is the last byte of the last message or last byte
+         * or any message without I2C_M_NOSTART, send a STOP.
           */
-        if (i2c->msg_ptr == i2c->msg->len &&
-            i2c->msg_idx == i2c->msg_num - 1)
-            icr |= ICR_STOP;
+        if (((i2c->msg_ptr == i2c->msg->len) &&
+            (!(i2c->msg->flags & I2C_M_NOSTART))) ||
+            ((i2c->msg_ptr == i2c->msg->len) &&
+            (i2c->msg_idx == i2c->msg_num - 1)))
+                icr |= ICR_STOP;
+
      } else if (i2c->msg_idx < i2c->msg_num - 1) {
          /*
           * Next segment of the message.
-- 
1.7.12.1

             reply	other threads:[~2014-11-22 22:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-22 22:52 Petr Cvek [this message]
2014-11-23  8:31 ` [PATCH] Add support for SCCB devices into PXA27x I2C controller Wolfram Sang
2014-11-23 22:21   ` [PATCH v2] " Petr Cvek
2014-11-24 17:27     ` Wolfram Sang
2014-11-25  5:05       ` [PATCH v3] i2c-pxa: add support for SCCB devices Petr Cvek
2014-11-25 14:26         ` Wolfram Sang
2014-11-23 16:23 ` [PATCH] Add support for SCCB devices into PXA27x I2C controller Sergei Shtylyov

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