diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0496-Fixes-i2c_bcm2708-Write-to-FIFO-correctly-v2-1574.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0496-Fixes-i2c_bcm2708-Write-to-FIFO-correctly-v2-1574.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0496-Fixes-i2c_bcm2708-Write-to-FIFO-correctly-v2-1574.patch b/target/linux/brcm2708/patches-4.4/0496-Fixes-i2c_bcm2708-Write-to-FIFO-correctly-v2-1574.patch new file mode 100644 index 0000000000..da46d86f09 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0496-Fixes-i2c_bcm2708-Write-to-FIFO-correctly-v2-1574.patch @@ -0,0 +1,48 @@ +From 1b6ee2ac8f1d55cb7ceeaa606e3d4868cfde363d Mon Sep 17 00:00:00 2001 +From: Simon Maes <simonn.maes@gmail.com> +Date: Mon, 29 Aug 2016 21:11:01 +0200 +Subject: [PATCH] Fixes i2c_bcm2708: Write to FIFO correctly - v2 (#1574) + +* i2c: fix i2c_bcm2708: Clear FIFO before sending data + +Make sure FIFO gets cleared before trying to send +data in case of a repeated start (COMBINED=Y). + +* i2c: fix i2c_bcm2708: Only write to FIFO when not full + +Check if FIFO can accept data before writing. +To avoid a peripheral read on the last iteration of a loop, +both bcm2708_bsc_fifo_fill and ~drain are changed as well. +--- + drivers/i2c/busses/i2c-bcm2708.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +--- a/drivers/i2c/busses/i2c-bcm2708.c ++++ b/drivers/i2c/busses/i2c-bcm2708.c +@@ -115,13 +115,13 @@ static inline void bcm2708_bsc_reset(str + + static inline void bcm2708_bsc_fifo_drain(struct bcm2708_i2c *bi) + { +- while ((bcm2708_rd(bi, BSC_S) & BSC_S_RXD) && (bi->pos < bi->msg->len)) ++ while ((bi->pos < bi->msg->len) && (bcm2708_rd(bi, BSC_S) & BSC_S_RXD)) + bi->msg->buf[bi->pos++] = bcm2708_rd(bi, BSC_FIFO); + } + + static inline void bcm2708_bsc_fifo_fill(struct bcm2708_i2c *bi) + { +- while ((bcm2708_rd(bi, BSC_S) & BSC_S_TXD) && (bi->pos < bi->msg->len)) ++ while ((bi->pos < bi->msg->len) && (bcm2708_rd(bi, BSC_S) & BSC_S_TXD)) + bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]); + } + +@@ -155,6 +155,10 @@ static inline int bcm2708_bsc_setup(stru + if ( (bi->nmsgs > 1) && + !(bi->msg[0].flags & I2C_M_RD) && (bi->msg[1].flags & I2C_M_RD) && + (bi->msg[0].addr == bi->msg[1].addr) && (bi->msg[0].len <= 16)) { ++ ++ /* Clear FIFO */ ++ bcm2708_wr(bi, BSC_C, BSC_C_CLEAR_1); ++ + /* Fill FIFO with entire write message (16 byte FIFO) */ + while (bi->pos < bi->msg->len) { + bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]); |