Commit 545f1da8 authored by Juuso Oikarinen's avatar Juuso Oikarinen Committed by John W. Linville
Browse files

wl1271: Implementation for SPI busy word checking 



This patch adds implementation for checking for SPI busy words - i.e.
honoring a delay request from the WLAN chipset upon reading
registers/memory.

To optimized the average SPI ready by 32 bits, also configure the number
of busywords to one to disable the "fixed-busy-word" functionality.

Signed-off-by: default avatarJuuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: default avatarVidhya Govindan <vidhya.govindan@nokia.com>
Signed-off-by: default avatarLuciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent c3fea199

drivers/net/wireless/wl12xx/wl1271.h

+8 −2
Original line number Diff line number Diff line
@@ -107,7 +107,13 @@ enum { 
#define WL1271_FW_NAME "wl1271-fw.bin"

#define WL1271_NVS_NAME "wl1271-nvs.bin"



#define WL1271_BUSY_WORD_LEN 8

/*

 * FIXME: for the wl1271, a busy word count of 1 here will result in a more

 * optimal SPI interface. There is some SPI bug however, causing RXS time outs

 * with this mode occasionally on boot, so lets have two for now.

 */

#define WL1271_BUSY_WORD_CNT 2

#define WL1271_BUSY_WORD_LEN (WL1271_BUSY_WORD_CNT * sizeof(u32))



#define WL1271_ELP_HW_STATE_ASLEEP 0

#define WL1271_ELP_HW_STATE_IRQ    1
@@ -389,7 +395,7 @@ struct wl1271 { 


	u32 buffer_32;

	u32 buffer_cmd;

	u8 buffer_busyword[WL1271_BUSY_WORD_LEN];

	u32 buffer_busyword[WL1271_BUSY_WORD_CNT];

	struct wl1271_rx_descriptor *rx_descriptor;



	struct wl1271_fw_status *fw_status;

drivers/net/wireless/wl12xx/wl1271_spi.c

+67 −2
Original line number Diff line number Diff line
@@ -244,12 +244,75 @@ int wl1271_set_partition(struct wl1271 *wl, 
	return 0;

}



#define WL1271_BUSY_WORD_TIMEOUT 1000



void wl1271_spi_read_busy(struct wl1271 *wl, void *buf, size_t len)

{

	struct spi_transfer t[1];

	struct spi_message m;

	u32 *busy_buf;

	int num_busy_bytes = 0;



	wl1271_info("spi read BUSY!");



	/*

	 * Look for the non-busy word in the read buffer, and if found,

	 * read in the remaining data into the buffer.

	 */

	busy_buf = (u32 *)buf;

	for (; (u32)busy_buf < (u32)buf + len; busy_buf++) {

		num_busy_bytes += sizeof(u32);

		if (*busy_buf & 0x1) {

			spi_message_init(&m);

			memset(t, 0, sizeof(t));

			memmove(buf, busy_buf, len - num_busy_bytes);

			t[0].rx_buf = buf + (len - num_busy_bytes);

			t[0].len = num_busy_bytes;

			spi_message_add_tail(&t[0], &m);

			spi_sync(wl->spi, &m);

			return;

		}

	}



	/*

	 * Read further busy words from SPI until a non-busy word is

	 * encountered, then read the data itself into the buffer.

	 */

	wl1271_info("spi read BUSY-polling needed!");



	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;

	busy_buf = wl->buffer_busyword;

	while (num_busy_bytes) {

		num_busy_bytes--;

		spi_message_init(&m);

		memset(t, 0, sizeof(t));

		t[0].rx_buf = busy_buf;

		t[0].len = sizeof(u32);

		spi_message_add_tail(&t[0], &m);

		spi_sync(wl->spi, &m);



		if (*busy_buf & 0x1) {

			spi_message_init(&m);

			memset(t, 0, sizeof(t));

			t[0].rx_buf = buf;

			t[0].len = len;

			spi_message_add_tail(&t[0], &m);

			spi_sync(wl->spi, &m);

			return;

		}

	}



	/* The SPI bus is unresponsive, the read failed. */

	memset(buf, 0, len);

	wl1271_error("SPI read busy-word timeout!\n");

}



void wl1271_spi_read(struct wl1271 *wl, int addr, void *buf,

		     size_t len, bool fixed)

{

	struct spi_transfer t[3];

	struct spi_message m;

	u8 *busy_buf;

	u32 *busy_buf;

	u32 *cmd;



	cmd = &wl->buffer_cmd;
@@ -281,7 +344,9 @@ void wl1271_spi_read(struct wl1271 *wl, int addr, void *buf, 


	spi_sync(wl->spi, &m);



	/* FIXME: check busy words */

	/* Check busy words */

	if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1))

		wl1271_spi_read_busy(wl, buf, len);



	wl1271_dump(DEBUG_SPI, "spi_read cmd -> ", cmd, sizeof(*cmd));

	wl1271_dump(DEBUG_SPI, "spi_read buf <- ", buf, len);