From patchwork Thu Aug 20 10:30:59 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vignesh Raghavendra X-Patchwork-Id: 7043491 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 588A9C05AC for ; Thu, 20 Aug 2015 10:31:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 77CEB20574 for ; Thu, 20 Aug 2015 10:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D5A220573 for ; Thu, 20 Aug 2015 10:31:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbbHTKbk (ORCPT ); Thu, 20 Aug 2015 06:31:40 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:55770 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbbHTKbj (ORCPT ); Thu, 20 Aug 2015 06:31:39 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id t7KAVa5g019732; Thu, 20 Aug 2015 05:31:36 -0500 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7KAVaRk019438; Thu, 20 Aug 2015 05:31:36 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.224.2; Thu, 20 Aug 2015 05:31:36 -0500 Received: from uda0132425.apr.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7KAVX6T010987; Thu, 20 Aug 2015 05:31:34 -0500 From: Vignesh R To: Mark Brown CC: , , , Vignesh R Subject: [PATCH] spi: ti-qspi: use 128 bit transfer mode for writing to flash Date: Thu, 20 Aug 2015 16:00:59 +0530 Message-ID: <1440066659-5356-1-git-send-email-vigneshr@ti.com> X-Mailer: git-send-email 2.5.0 MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP TI QSPI has four 32 bit data regsiters which can be used to transfer 16 bytes of data at once. The register group QSPI_SPI_DATA_REG_3, QSPI_SPI_DATA_REG_2, QSPI_SPI_DATA_REG_1 and QSPI_SPI_DATA_REG is treated as a single 128-bit word for shifting data in and out. The bit at QSPI_SPI_DATA_REG_3[31] position is the first bit to be shifted out in case of 128 bit transfer mode. Therefore the first byte to be written to flash should be at QSPI_SPI_DATA_REG_3[31-25] position. Instead of writing 1 byte at a time when interacting with spi-nor flash, make use of all the four registers so that 16 bytes can be transferred in one go. This reduces number of register writes and Word Complete interrupts for a given transfer message size, thereby increasing the write performance. Without this patch the raw flash write speed is ~100KB/s, with this patch the write speed increases to ~400 kB/s on DRA74 EVM. Signed-off-by: Vignesh R --- drivers/spi/spi-ti-qspi.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 45844a227c5e..f4cea6834fad 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -96,6 +96,8 @@ struct ti_qspi { #define QSPI_INVAL (4 << 16) #define QSPI_WC_CMD_INT_EN (1 << 14) #define QSPI_FLEN(n) ((n - 1) << 0) +#define QSPI_WLEN_MAX_BITS 128 +#define QSPI_WLEN_MAX_BYTES 16 /* STATUS REGISTER */ #define BUSY 0x01 @@ -224,14 +226,16 @@ static inline u32 qspi_is_busy(struct ti_qspi *qspi) static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) { - int wlen, count; + int wlen, count, xfer_len; unsigned int cmd; const u8 *txbuf; + u32 data; txbuf = t->tx_buf; cmd = qspi->cmd | QSPI_WR_SNGL; count = t->len; wlen = t->bits_per_word >> 3; /* in bytes */ + xfer_len = wlen; while (count) { if (qspi_is_busy(qspi)) @@ -241,7 +245,29 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) case 1: dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n", cmd, qspi->dc, *txbuf); - writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG); + if (count >= QSPI_WLEN_MAX_BYTES) { + u32 *txp = (u32 *)txbuf; + + data = cpu_to_be32(*txp++); + writel(data, qspi->base + + QSPI_SPI_DATA_REG_3); + data = cpu_to_be32(*txp++); + writel(data, qspi->base + + QSPI_SPI_DATA_REG_2); + data = cpu_to_be32(*txp++); + writel(data, qspi->base + + QSPI_SPI_DATA_REG_1); + data = cpu_to_be32(*txp++); + writel(data, qspi->base + + QSPI_SPI_DATA_REG); + xfer_len = QSPI_WLEN_MAX_BYTES; + cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS); + } else { + writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG); + cmd = qspi->cmd | QSPI_WR_SNGL; + xfer_len = wlen; + cmd |= QSPI_WLEN(wlen); + } break; case 2: dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n", @@ -261,8 +287,8 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) dev_err(qspi->dev, "write timed out\n"); return -ETIMEDOUT; } - txbuf += wlen; - count -= wlen; + txbuf += xfer_len; + count -= xfer_len; } return 0;