Re: [alsa-devel] [PATCH 3/9] ASoC: ipq806x: add native LPAIF driver

On Thu, November 20, 2014 4:32 am, Lars-Peter Clausen wrote:

On 11/19/2014 07:52 PM, Kenneth Westfield wrote:

quoted

From: Kenneth Westfield <redacted>

Add the native LPAIF driver for LPASS block in Qualcomm
Technologies SoCs.

Change-Id: I0f06f73a1267d7721209e58ce18e0d4897001141
Signed-off-by: Kenneth Westfield <redacted>
Signed-off-by: Banajit Goswami <redacted>
---
  sound/soc/qcom/lpass-lpaif.c | 488 +++++++++++++++++++++++++++++++++++++++++++
  sound/soc/qcom/lpass-lpaif.h | 181 ++++++++++++++++
  2 files changed, 669 insertions(+)
  create mode 100644 sound/soc/qcom/lpass-lpaif.c
  create mode 100644 sound/soc/qcom/lpass-lpaif.h

diff --git a/sound/soc/qcom/lpass-lpaif.c b/sound/soc/qcom/lpass-lpaif.c
new file mode 100644
index 0000000000000000000000000000000000000000..e62843fe9bc4c63c3c7c119a9f076085b16a56b3
--- /dev/null
+++ b/sound/soc/qcom/lpass-lpaif.c

@@ -0,0 +1,488 @@
+/*
+ * Copyright (c) 2010-2011,2013-2014 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/clk.h>
+#include <linux/types.h>
+#include <sound/soc.h>
+#include "lpass-lpaif.h"
+
+#define DRV_NAME	"lpass-lpaif"
+#define DRV_VERSION	"1.0"
+
+struct lpaif_dai_baseinfo {
+	void __iomem *base;
+};
+
+struct lpaif_dai_drv {
+	unsigned char *buffer;
+	dma_addr_t buffer_phys;
+	int channels;
+	irqreturn_t (*callback)(int intrsrc, void *private_data);
+	void *private_data;
+	int in_use;
+	unsigned int buffer_len;
+	unsigned int period_len;
+	unsigned int master_mode;
+};
+
+static struct lpaif_dai_baseinfo lpaif_dai_info;
+static struct lpaif_dai_drv *lpaif_dai[LPAIF_MAX_CHANNELS];
+static spinlock_t lpaif_lock;
+static struct resource *lpaif_irq;

Please don't use global state for device drivers. Make the state device
instance specific.

quoted

+

[...]

quoted

+
+static int lpaif_dai_probe(struct platform_device *pdev)
+{
+	uint8_t i;
+	int32_t rc;
+	struct resource *lpa_res;
+	struct device *lpaif_device;
+
+	lpaif_device = &pdev->dev;
+
+	lpa_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+			"lpass-lpaif-mem");
+	if (!lpa_res) {
+		dev_err(&pdev->dev, "%s: error getting resource\n", __func__);
+		return -ENODEV;
+	}
+	lpaif_dai_info.base = ioremap(lpa_res->start,
+			(lpa_res->end - lpa_res->start));

It's probably better to use devm_ioremap_resource here.

quoted

+	if (!lpaif_dai_info.base) {
+		dev_err(&pdev->dev, "%s: error remapping resource\n",
+				__func__);
+		return -ENOMEM;
+	}
+
+	lpaif_irq = platform_get_resource_byname(
+			pdev, IORESOURCE_IRQ, "lpass-lpaif-irq");

platform_get_irq_byname

quoted

+	if (!lpaif_irq) {
+		dev_err(&pdev->dev, "%s: failed get irq res\n", __func__);
+		rc = -ENODEV;
+		goto error;
+	}
+
+	rc = request_irq(lpaif_irq->start, lpaif_dai_irq_handler,
+			IRQF_TRIGGER_RISING, "lpass-lpaif-intr", NULL);
+
+	if (rc < 0) {
+		dev_err(&pdev->dev, "%s: irq resource request failed\n",
+				__func__);
+		goto error;
+	}
+
+	/*
+	 * Allocating memory for all the LPA_IF DMA channels
+	 */
+	for (i = 0; i < LPAIF_MAX_CHANNELS; i++) {
+		lpaif_dai[i] = kzalloc(sizeof(struct lpaif_dai_drv),
+				GFP_KERNEL);
+		if (!lpaif_dai[i]) {
+			rc = -ENOMEM;
+			goto error_irq;
+		}
+	}
+	spin_lock_init(&lpaif_lock);

This needs to be initialized before you request the interrupt as the
interrupt handler is using the spinlock.

quoted

+	return 0;
+
+error_irq:
+	free_irq(lpaif_irq->start, NULL);
+	lpaif_dai_ch_free();
+error:
+	iounmap(lpaif_dai_info.base);
+	return rc;
+}
+
+static int lpaif_dai_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < LPAIF_MAX_CHANNELS; i++)
+		lpaif_dai_stop(i);
+	synchronize_irq(lpaif_irq->start);

free_irq does a synchronize_irq, not need to call it manually.

quoted

+	free_irq(lpaif_irq->start, NULL);
+	iounmap(lpaif_dai_info.base);
+	lpaif_dai_ch_free();
+	return 0;
+}
+

[..]
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Lars

Thank you for your comments.  I will separately address each comment shortly.

-- 
Kenneth Westfield
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project