ata: add new-style AHCI platform driver for DaVinci DA850 AHCI controller

Add the new ahci_da850 host driver.

Platform changes needed to make DaVinci DA850 SATA AHCI support
fully functional are in the separate "ARM: davinci: da850: update
SATA AHCI support" commit.

Please note that this driver doesn't have the superfluous clock
control code as clock is already handled by the generic AHCI
platform library code.

Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/Kconfig

@@ -97,6 +97,15 @@ config SATA_AHCI_PLATFORM
 
 	  If unsure, say N.
 
+config AHCI_DA850
+	tristate "DaVinci DA850 AHCI SATA support"
+	depends on ARCH_DAVINCI_DA850
+	help
+	  This option enables support for the DaVinci DA850 SoC's
+	  onboard AHCI SATA.
+
+	  If unsure, say N.
+
 config AHCI_ST
 	tristate "ST AHCI SATA support"
 	depends on ARCH_STI

drivers/ata/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_SATA_INIC162X)	+= sata_inic162x.o
 obj-$(CONFIG_SATA_SIL24)	+= sata_sil24.o
 obj-$(CONFIG_SATA_DWC)		+= sata_dwc_460ex.o
 obj-$(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-$(CONFIG_AHCI_SUNXI)	+= ahci_sunxi.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_ST)		+= ahci_st.o libahci.o libahci_platform.o

drivers/ata/ahci_da850.c

@@ -0,0 +1,114 @@
+/*
+ * DaVinci DA850 AHCI SATA platform driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ */
+
+#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"
+
+/* SATA PHY Control Register offset from AHCI base */
+#define SATA_P0PHYCR_REG	0x178
+
+#define SATA_PHY_MPY(x)		((x) << 0)
+#define SATA_PHY_LOS(x)		((x) << 6)
+#define SATA_PHY_RXCDR(x)	((x) << 10)
+#define SATA_PHY_RXEQ(x)	((x) << 13)
+#define SATA_PHY_TXSWING(x)	((x) << 19)
+#define SATA_PHY_ENPLL(x)	((x) << 31)
+
+/*
+ * The multiplier needed for 1.5GHz PLL output.
+ *
+ * NOTE: This is currently hardcoded to be suitable for 100MHz crystal
+ * frequency (which is used by DA850 EVM board) and may need to be changed
+ * if you would like to use this driver on some other board.
+ */
+#define DA850_SATA_CLK_MULTIPLIER	7
+
+static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
+			    void __iomem *ahci_base)
+{
+	unsigned int val;
+
+	/* Enable SATA clock receiver */
+	val = readl(pwrdn_reg);
+	val &= ~BIT(0);
+	writel(val, pwrdn_reg);
+
+	val = SATA_PHY_MPY(DA850_SATA_CLK_MULTIPLIER + 1) | SATA_PHY_LOS(1) |
+	      SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) |
+	      SATA_PHY_ENPLL(1);
+
+	writel(val, ahci_base + SATA_P0PHYCR_REG);
+}
+
+static const struct ata_port_info ahci_da850_port_info = {
+	.flags		= AHCI_FLAG_COMMON,
+	.pio_mask	= ATA_PIO4,
+	.udma_mask	= ATA_UDMA6,
+	.port_ops	= &ahci_platform_ops,
+};
+
+static int ahci_da850_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ahci_host_priv *hpriv;
+	struct resource *res;
+	void __iomem *pwrdn_reg;
+	int rc;
+
+	hpriv = ahci_platform_get_resources(pdev);
+	if (IS_ERR(hpriv))
+		return PTR_ERR(hpriv);
+
+	rc = ahci_platform_enable_resources(hpriv);
+	if (rc)
+		return rc;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		goto disable_resources;
+
+	pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res));
+	if (!pwrdn_reg)
+		goto disable_resources;
+
+	da850_sata_init(dev, pwrdn_reg, hpriv->mmio);
+
+	rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info, 0, 0);
+	if (rc)
+		goto disable_resources;
+
+	return 0;
+disable_resources:
+	ahci_platform_disable_resources(hpriv);
+	return rc;
+}
+
+static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
+			 ahci_platform_resume);
+
+static struct platform_driver ahci_da850_driver = {
+	.probe = ahci_da850_probe,
+	.remove = ata_platform_remove_one,
+	.driver = {
+		.name = "ahci_da850",
+		.owner = THIS_MODULE,
+		.pm = &ahci_da850_pm_ops,
+	},
+};
+module_platform_driver(ahci_da850_driver);
+
+MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver");
+MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>");
+MODULE_LICENSE("GPL");