From f76f86029d75df2546e734e3ae1a50fa62d72526 Mon Sep 17 00:00:00 2001 From: Sai Pavan Boddu Date: Tue, 1 Mar 2022 09:16:52 +0100 Subject: [PATCH] i2c: i2c-cdns: Prevent early termination of write During sequential loading of data, hold the bus to prevent controller from sending stop signal in case no data is available in fifo. Signed-off-by: Sai Pavan Boddu Reviewed-by: Ashok Reddy Soma Signed-off-by: Michal Simek Link: https://lore.kernel.org/r/2407b39d305999cb42438c5423aebc3b514acabb.1646122610.git.michal.simek@xilinx.com --- drivers/i2c/i2c-cdns.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/i2c-cdns.c b/drivers/i2c/i2c-cdns.c index 07d53be..0da9f6f 100644 --- a/drivers/i2c/i2c-cdns.c +++ b/drivers/i2c/i2c-cdns.c @@ -257,16 +257,18 @@ static int cdns_i2c_write_data(struct i2c_cdns_bus *i2c_bus, u32 addr, u8 *data, setbits_le32(®s->control, CDNS_I2C_CONTROL_CLR_FIFO); clrbits_le32(®s->control, CDNS_I2C_CONTROL_RW); - /* Check message size against FIFO depth, and set hold bus bit - * if it is greater than FIFO depth + /* + * For sequential data load hold the bus. */ - if (len > CDNS_I2C_FIFO_DEPTH) + if (len > 1) setbits_le32(®s->control, CDNS_I2C_CONTROL_HOLD); /* Clear the interrupts in status register */ writel(CDNS_I2C_INTERRUPTS_MASK, ®s->interrupt_status); - writel(addr, ®s->address); + /* In case of Probe (i.e no data), start the transfer */ + if (!len) + writel(addr, ®s->address); while (len-- && !is_arbitration_lost(regs)) { writel(*(cur_data++), ®s->data); -- 2.7.4