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From: zhangfei.gao@linaro.org (Zhangfei Gao)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: designware: add reset interface
Date: Tue, 22 Nov 2016 12:41:40 +0800	[thread overview]
Message-ID: <1479789700-19532-1-git-send-email-zhangfei.gao@linaro.org> (raw)

Some platforms like hi3660 need do reset first to allow accessing registers

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 drivers/i2c/busses/i2c-designware-core.h    | 1 +
 drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 0d44d2a..94b14fa 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -80,6 +80,7 @@ struct dw_i2c_dev {
 	void __iomem		*base;
 	struct completion	cmd_complete;
 	struct clk		*clk;
+	struct reset_control	*rst;
 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
 	struct dw_pci_controller *controller;
 	int			cmd_err;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..fd80e58 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -38,6 +38,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/io.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/platform_data/i2c-designware.h>
@@ -176,6 +177,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	dev->irq = irq;
 	platform_set_drvdata(pdev, dev);
 
+	dev->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (!IS_ERR(dev->rst))
+		reset_control_reset(dev->rst);
+
 	/* fast mode by default because of legacy reasons */
 	dev->clk_freq = 400000;
 
-- 
2.7.4

             reply	other threads:[~2016-11-22  4:41 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-22  4:41 Zhangfei Gao [this message]
2016-12-13 20:34 ` [PATCH] i2c: designware: add reset interface Wolfram Sang
2016-12-14 19:00   ` Andy Shevchenko
2016-12-15  8:56     ` zhangfei
2016-12-15  8:59 ` [PATCH v2] " Zhangfei Gao
2016-12-15 12:33   ` Andy Shevchenko
2016-12-15 14:11     ` Phil Reid
2016-12-15 15:40       ` Jarkko Nikula
2016-12-15 15:30     ` Ramiro Oliveira
2016-12-16  2:45       ` zhangfei
2016-12-16  3:01         ` zhangfei
2016-12-23 10:26           ` Philipp Zabel
2016-12-23 13:39             ` zhangfei

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