mtd: st_spi_fsm: Supply a method to read from the FSM's FIFO

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=030e82dc6386f23bcd05876b452d2618dd8046b4
Commit:     030e82dc6386f23bcd05876b452d2618dd8046b4
Parent:     3c8b85b340c7a6b47d50c12c03661c23a5858b88
Author:     Lee Jones <lee.jones at linaro.org>
AuthorDate: Thu Mar 20 09:20:37 2014 +0000
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Thu Mar 20 04:17:14 2014 -0700

    mtd: st_spi_fsm: Supply a method to read from the FSM's FIFO
    
    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.
    
    Acked-by Angus Clark <angus.clark at st.com>
    Signed-off-by: Lee Jones <lee.jones at linaro.org>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 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 5e22c86..73e0f27 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -281,6 +281,32 @@ 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;