[PATCH v3 2/3] ata: Add Qualcomm ARM SoC AHCI SATA host controller driver

[Kumar Gala <galak@codeaurora.org>]

Add support for the Qualcomm AHCI SATA controller that exists on several
SoC and specifically the IPQ806x family of chips.  The IPQ806x SATA support
requires the associated IPQ806x SATA PHY Driver to be enabled as well.

Signed-off-by: Kumar Gala <galak@codeaurora.org>
---
v3:
* Added comment about suspend/resume not supported
* Fixup ahci_platform_init_host for upstream change to interface
* cleanup error handling of rxoob clk, moved to devm_clk_get/put

v2:
* Fixed MODULE_LICENSE to be GPL v2

 drivers/ata/Kconfig     | 10 ++++++
 drivers/ata/Makefile    |  1 +
 drivers/ata/ahci_qcom.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 101 insertions(+)
 create mode 100644 drivers/ata/ahci_qcom.c

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 7671dba..aa88648 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -132,6 +132,16 @@ config AHCI_MVEBU
 
 	  If unsure, say N.
 
+config AHCI_QCOM
+	tristate "Qualcomm AHCI SATA support"
+	depends on ARCH_QCOM
+	help
+	  This option enables support for AHCI SATA controller
+	  integrated into Qualcomm ARM SoC chipsets. For more
+	  information please refer to http://www.qualcomm.com/chipsets.
+
+	  If unsure, say N.
+
 config AHCI_SUNXI
 	tristate "Allwinner sunxi AHCI SATA support"
 	depends on ARCH_SUNXI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 5a02aee..15401e9 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_SATA_HIGHBANK)	+= sata_highbank.o libahci.o
 obj-$(CONFIG_AHCI_DA850)	+= ahci_da850.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_IMX)		+= ahci_imx.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_MVEBU)	+= ahci_mvebu.o libahci.o libahci_platform.o
+obj-$(CONFIG_AHCI_QCOM)		+= ahci_qcom.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_SUNXI)	+= ahci_sunxi.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_ST)		+= ahci_st.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_XGENE)	+= ahci_xgene.o libahci.o libahci_platform.o
diff --git a/drivers/ata/ahci_qcom.c b/drivers/ata/ahci_qcom.c
new file mode 100644
index 0000000..412e878
--- /dev/null
+++ b/drivers/ata/ahci_qcom.c
@@ -0,0 +1,90 @@
+/*
+ * Qualcomm ARM SoC AHCI SATA platform driver
+ *
+ * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov
+ *
+ * Copyright (c) 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/kernel.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/libata.h>
+#include <linux/ahci_platform.h>
+#include "ahci.h"
+
+static const struct ata_port_info qcom_ahci_port_info = {
+	.flags		= AHCI_FLAG_COMMON,
+	.pio_mask	= ATA_PIO4,
+	.udma_mask	= ATA_UDMA6,
+	.port_ops	= &ahci_platform_ops,
+};
+
+static int qcom_ahci_probe(struct platform_device *pdev)
+{
+	struct ahci_host_priv *hpriv;
+	struct clk *rxoob_clk;
+	int rc;
+
+	hpriv = ahci_platform_get_resources(pdev);
+	if (IS_ERR(hpriv))
+		return PTR_ERR(hpriv);
+
+	/* Try and set the rxoob clk to 100Mhz */
+	rxoob_clk = devm_clk_get(&pdev->dev, "rxoob");
+	if (IS_ERR(rxoob_clk))
+		return PTR_ERR(rxoob_clk);
+
+	rc = clk_set_rate(rxoob_clk, 100000000);
+	if (rc)
+		return rc;
+
+	devm_clk_put(&pdev->dev, rxoob_clk);
+
+	rc = ahci_platform_enable_resources(hpriv);
+	if (rc)
+		return rc;
+
+	rc = ahci_platform_init_host(pdev, hpriv, &qcom_ahci_port_info,
+				     0, 0, 0);
+	if (rc)
+		goto disable_resources;
+
+	return 0;
+disable_resources:
+	ahci_platform_disable_resources(hpriv);
+	return rc;
+}
+
+static const struct of_device_id qcom_ahci_of_match[] = {
+	{ .compatible = "qcom,msm-ahci", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, qcom_ahci_of_match);
+
+static struct platform_driver qcom_ahci_driver = {
+	.probe = qcom_ahci_probe,
+	.remove = ata_platform_remove_one,
+	.driver = {
+		.name = "qcom_ahci_qcom",
+		.owner = THIS_MODULE,
+		.of_match_table = qcom_ahci_of_match,
+	},
+	/* suspend/resume not currently supported */
+};
+module_platform_driver(qcom_ahci_driver);
+
+MODULE_DESCRIPTION("Qualcomm AHCI SATA platform driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("ahci:qcom");
-- 
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