From 545f1da8ef0f20923feb500bcfaf0e2fb6068fb4 Mon Sep 17 00:00:00 2001 From: Juuso Oikarinen Date: Thu, 8 Oct 2009 21:56:23 +0300 Subject: [PATCH] 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: Juuso Oikarinen Reviewed-by: Vidhya Govindan Signed-off-by: Luciano Coelho Signed-off-by: John W. Linville --- drivers/net/wireless/wl12xx/wl1271.h | 10 +++- drivers/net/wireless/wl12xx/wl1271_spi.c | 69 +++++++++++++++++++++++- 2 files changed, 75 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/wl12xx/wl1271.h b/drivers/net/wireless/wl12xx/wl1271.h index c455dcbae52..957da8c0d9c 100644 --- a/drivers/net/wireless/wl12xx/wl1271.h +++ b/drivers/net/wireless/wl12xx/wl1271.h @@ -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; diff --git a/drivers/net/wireless/wl12xx/wl1271_spi.c b/drivers/net/wireless/wl12xx/wl1271_spi.c index 4a12880c16a..504991acb05 100644 --- a/drivers/net/wireless/wl12xx/wl1271_spi.c +++ b/drivers/net/wireless/wl12xx/wl1271_spi.c @@ -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); -- 2.41.0