[PATCH v5 2/2] i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support

Hello Wolfram,

On 10/06/2014 21:45, Wolfram Sang wrote:

Hi,

compiling this driver gives me:

drivers/i2c/busses/i2c-sun6i-p2wi.c: In function 'p2wi_probe':
drivers/i2c/busses/i2c-sun6i-p2wi.c:272:2: error: implicit declaration of function 'devm_reset_control_get' [-Werror=implicit-function-declaration]
drivers/i2c/busses/i2c-sun6i-p2wi.c:272:13: warning: assignment makes pointer from integer without a cast [enabled by default]

Yes, there's a missing "depends on RESET_CONTROLLER" in the Kconfig
entry, which I didn't notice because this option was selected by the
sun6i platform.

quoted

diff --git a/drivers/i2c/busses/i2c-sun6i-p2wi.c b/drivers/i2c/busses/i2c-sun6i-p2wi.c
new file mode 100644
index 0000000..4f7b93f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-sun6i-p2wi.c

@@ -0,0 +1,356 @@
+/*
+ * P2WI (Push-Pull Two Wire Interface) bus driver.
+ *
+ * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ * The P2WI controller looks like an SMBus controller which only supports byte
+ * data transfers. But, it differs from standard SMBus protocol on several
+ * aspects:
+ * - it supports only one slave device, and thus drop the address field
+ * - it adds a parity bit every 8bits of data
+ * - only one read access is required to read a byte (instead of a write
+ *   followed by a read access in standard SMBus protocol)
+ * - there's no Ack bit after each byte transfer
+ *
+ * This means this bus cannot be used to interface with standard SMBus
+ * devices (the only known device to support this interface is the AXP221
+ * PMIC).
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>

Unneeded. Please check other includes, too.

Okay, I'll clean it up.

quoted

+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+

...

quoted

+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	p2wi->regs = devm_ioremap_resource(dev, r);
+	if (IS_ERR(p2wi->regs)) {
+		ret = PTR_ERR(p2wi->regs);
+		return ret;
+	}

return PTR_ERR(...)?

Oops, some vestige of my previous dev_err call.

quoted

+
+	snprintf(p2wi->adapter.name, sizeof(p2wi->adapter.name), pdev->name);
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to retrieve irq: %d\n", ret);
+		return irq;
+	}
+
+	p2wi->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(p2wi->clk)) {
+		ret = PTR_ERR(p2wi->clk);
+		dev_err(dev, "failed to retrieve clk: %d\n",
+			ret);

dangling ret.

I'll fix it.

Thanks,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com