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Groups > linux.kernel > #1199703
| Path | csiph.com!usenet.pasdenom.info!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | Eddie Huang <eddie.huang@mediatek.com> |
| Newsgroups | linux.kernel |
| Subject | [PATCH 1/2] i2c: mediatek: Reset DMA engine in hardware init function |
| Date | Tue, 04 Aug 2015 13:50:01 +0200 |
| Message-ID | <pTITf-10n-5@gated-at.bofh.it> (permalink) |
| References | <pTITf-10n-3@gated-at.bofh.it> |
| X-Original-To | Wolfram Sang <wsa@the-dreams.de> |
| X-Listener-Flag | 11101 |
| X-Mailer | git-send-email 1.7.9.5 |
| MIME-Version | 1.0 |
| Content-Type | text/plain |
| X-Mtk | N |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 58 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | <srv_heupstream@mediatek.com>, Matthias Brugger <matthias.bgg@gmail.com>, Liguo Zhang <liguo.zhang@mediatek.com>, Xudong Chen <xudong.chen@mediatek.com>, Sascha Hauer <s.hauer@pengutronix.de>, <linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-mediatek@lists.infradead.org>, Eddie Huang <eddie.huang@mediatek.com> |
| X-Original-Date | Tue, 4 Aug 2015 19:44:52 +0800 |
| X-Original-Message-ID | <1438688693-60275-2-git-send-email-eddie.huang@mediatek.com> |
| X-Original-References | <1438688693-60275-1-git-send-email-eddie.huang@mediatek.com> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1199703 |
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Reset DMA in hardware init function to avoid unknown hardware state
before do any I2C operation.
Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
---
drivers/i2c/busses/i2c-mt65xx.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 9920eef..055159d 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -1,6 +1,8 @@
/*
* Copyright (c) 2014 MediaTek Inc.
- * Author: Xudong Chen <xudong.chen@mediatek.com>
+ * Author:
+ * Xudong Chen <xudong.chen@mediatek.com>
+ * Liguo Zhang <liguo.zhang@mediatek.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -59,6 +61,7 @@
#define I2C_DMA_START_EN 0x0001
#define I2C_DMA_INT_FLAG_NONE 0x0000
#define I2C_DMA_CLR_FLAG 0x0000
+#define I2C_DMA_HARD_RST 0x0002
#define I2C_DEFAULT_SPEED 100000 /* hz */
#define MAX_FS_MODE_SPEED 400000
@@ -81,6 +84,7 @@ enum DMA_REGS_OFFSET {
OFFSET_INT_FLAG = 0x0,
OFFSET_INT_EN = 0x04,
OFFSET_EN = 0x08,
+ OFFSET_RST = 0x0c,
OFFSET_CON = 0x18,
OFFSET_TX_MEM_ADDR = 0x1c,
OFFSET_RX_MEM_ADDR = 0x20,
@@ -262,6 +266,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
writew(control_reg, i2c->base + OFFSET_CONTROL);
writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
+
+ writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
+ udelay(50);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
}
/*
--
1.7.9.5
--
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[PATCH 0/2] Mediatek I2C fixup Eddie Huang <eddie.huang@mediatek.com> - 2015-08-04 13:50 +0200 [PATCH 1/2] i2c: mediatek: Reset DMA engine in hardware init function Eddie Huang <eddie.huang@mediatek.com> - 2015-08-04 13:50 +0200
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