[PATCH v3 05/36] mtd: st_spi_fsm: Supply a method to read from the FSM's FIFO

Lee Jones lee.jones at linaro.org
Fri Nov 29 07:18:54 EST 2013


When invoked the driver will attempt to read any available data from
the FSM's data register. Any data collected from this FIFO would have
originated from the flash chip.

Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/mtd/devices/st_spi_fsm.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 8ac8cd9..05fa834 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -81,6 +81,32 @@ static void stfsm_wait_seq(struct stfsm *fsm)
 	dev_err(fsm->dev, "timeout on sequence completion\n");
 }
 
+static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf,
+			    const uint32_t size)
+{
+	uint32_t remaining = size >> 2;
+	uint32_t avail;
+	uint32_t words;
+
+	dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
+
+	BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
+
+	while (remaining) {
+		for (;;) {
+			avail = stfsm_fifo_available(fsm);
+			if (avail)
+				break;
+			udelay(1);
+		}
+		words = min(avail, remaining);
+		remaining -= words;
+
+		readsl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
+		buf += words;
+	}
+}
+
 static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
 {
 	int ret, timeout = 10;
-- 
1.8.3.2




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