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Commit cd086d3a authored by Sonasath, Moiz's avatar Sonasath, Moiz Committed by Ben Dooks
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i2c-omap: OMAP3430 Silicon Errata 1.153 



When an XRDY/XDR is hit, wait for XUDF before writing data to DATA_REG.
Otherwise some data bytes can be lost while transferring them from the
memory to the I2C interface.

Do a Busy-wait for XUDF, before writing data to DATA_REG. While waiting
if there is NACK | AL, set the appropriate error flags, ack the pending
interrupts and return from the ISR.

Signed-off-by: default avatarMoiz Sonasath <m-sonasath@ti.com>
Signed-off-by: default avatarVikram pandita <vikram.pandita@ti.com>
[ben-linux@fluff.org: fixed mail format and added i2c-omap to subject]
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 04c688dd

drivers/i2c/busses/i2c-omap.c

+23 −1
Original line number Diff line number Diff line
@@ -672,9 +672,10 @@ omap_i2c_isr(int this_irq, void *dev_id) 
			break;

		}



		err = 0;

complete:

		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);



		err = 0;

		if (stat & OMAP_I2C_STAT_NACK) {

			err |= OMAP_I2C_STAT_NACK;

			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
@@ -764,6 +765,27 @@ omap_i2c_isr(int this_irq, void *dev_id) 
							"data to send\n");

					break;

				}



				/*

				 * OMAP3430 Errata 1.153: When an XRDY/XDR

				 * is hit, wait for XUDF before writing data

				 * to DATA_REG. Otherwise some data bytes can

				 * be lost while transferring them from the

				 * memory to the I2C interface.

				 */



				if (cpu_is_omap34xx()) {

						while (!(stat & OMAP_I2C_STAT_XUDF)) {

							if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {

								omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));

								err |= OMAP_I2C_STAT_XUDF;

								goto complete;

							}

							cpu_relax();

							stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);

						}

				}



				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);

			}

			omap_i2c_ack_stat(dev,