ata: Add driver for Faraday Technology FTIDE010

This adds a driver for the Faraday Technology FTIDE010
PATA IP block.

When used with the Storlink/Storm/Cortina Systems Gemini
SoC, the PATA interface is accompanied by a PATA<->SATA
bridge, so while the device appear as a PATA controller,
it attaches physically to SATA disks, and also has a
designated memory area with registers to set up the bridge.

The Gemini SATA bridge is separated into its own driver
file to make things modular and make it possible to reuse
the PATA driver as stand-alone on other systems than the
Gemini.

dmesg excerpt from the D-Link DIR-685 storage router:
gemini-sata-bridge 46000000.sata: SATA ID 00000e00, PHY ID: 01000100
gemini-sata-bridge 46000000.sata: set up the Gemini IDE/SATA nexus
ftide010 63000000.ata: set up Gemini PATA0
ftide010 63000000.ata: device ID 00000500, irq 26, io base 0x63000000
ftide010 63000000.ata: SATA0 (master) start
gemini-sata-bridge 46000000.sata: SATA0 PHY ready
scsi host0: pata-ftide010
ata1: PATA max UDMA/133 irq 26
ata1.00: ATA-8: INTEL SSDSA2CW120G3, 4PC10302, max UDMA/133
ata1.00: 234441648 sectors, multi 1: LBA48 NCQ (depth 0/32)
ata1.00: configured for UDMA/133
scsi 0:0:0:0: Direct-Access     ATA      INTEL SSDSA2CW12 0302 PQ: 0 ANSI: 5
ata1.00: Enabling discard_zeroes_data
sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 GB/112 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Write cache: enabled, read cache:
                  enabled, doesn't support DPO or FUA
ata1.00: Enabling discard_zeroes_data
ata1.00: Enabling discard_zeroes_data
sd 0:0:0:0: [sda] Attached SCSI disk

After this I can flawlessly mount and read/write copy etc files
from /dev/sda[n].

Cc: John Feng-Hsin Chiang <john453@faraday-tech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 438 insertions, 0 deletions

diff --git a/drivers/ata/sata_gemini.c b/drivers/ata/sata_gemini.c
new file mode 100644
index 000000000000..8c704523bae7
--- /dev/null
+++ b/drivers/ata/sata_gemini.c
@@ -0,0 +1,438 @@
+/*
+ * Cortina Systems Gemini SATA bridge add-on to Faraday FTIDE010
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/reset.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include "sata_gemini.h"
+
+#define DRV_NAME "gemini_sata_bridge"
+
+/**
+ * struct sata_gemini - a state container for a Gemini SATA bridge
+ * @dev: the containing device
+ * @base: remapped I/O memory base
+ * @muxmode: the current muxing mode
+ * @ide_pins: if the device is using the plain IDE interface pins
+ * @sata_bridge: if the device enables the SATA bridge
+ * @sata0_reset: SATA0 reset handler
+ * @sata1_reset: SATA1 reset handler
+ * @sata0_pclk: SATA0 PCLK handler
+ * @sata1_pclk: SATA1 PCLK handler
+ */
+struct sata_gemini {
+	struct device *dev;
+	void __iomem *base;
+	enum gemini_muxmode muxmode;
+	bool ide_pins;
+	bool sata_bridge;
+	struct reset_control *sata0_reset;
+	struct reset_control *sata1_reset;
+	struct clk *sata0_pclk;
+	struct clk *sata1_pclk;
+};
+
+/* Global IDE PAD Skew Control Register */
+#define GEMINI_GLOBAL_IDE_SKEW_CTRL		0x18
+#define GEMINI_IDE1_HOST_STROBE_DELAY_SHIFT	28
+#define GEMINI_IDE1_DEVICE_STROBE_DELAY_SHIFT	24
+#define GEMINI_IDE1_OUTPUT_IO_SKEW_SHIFT	20
+#define GEMINI_IDE1_INPUT_IO_SKEW_SHIFT		16
+#define GEMINI_IDE0_HOST_STROBE_DELAY_SHIFT	12
+#define GEMINI_IDE0_DEVICE_STROBE_DELAY_SHIFT	8
+#define GEMINI_IDE0_OUTPUT_IO_SKEW_SHIFT	4
+#define GEMINI_IDE0_INPUT_IO_SKEW_SHIFT		0
+
+/* Miscellaneous Control Register */
+#define GEMINI_GLOBAL_MISC_CTRL		0x30
+/*
+ * Values of IDE IOMUX bits in the misc control register
+ *
+ * Bits 26:24 are "IDE IO Select", which decides what SATA
+ * adapters are connected to which of the two IDE/ATA
+ * controllers in the Gemini. We can connect the two IDE blocks
+ * to one SATA adapter each, both acting as master, or one IDE
+ * blocks to two SATA adapters so the IDE block can act in a
+ * master/slave configuration.
+ *
+ * We also bring out different blocks on the actual IDE
+ * pins (not SATA pins) if (and only if) these are muxed in.
+ *
+ * 111-100 - Reserved
+ * Mode 0: 000 - ata0 master <-> sata0
+ *               ata1 master <-> sata1
+ *               ata0 slave interface brought out on IDE pads
+ * Mode 1: 001 - ata0 master <-> sata0
+ *               ata1 master <-> sata1
+ *               ata1 slave interface brought out on IDE pads
+ * Mode 2: 010 - ata1 master <-> sata1
+ *               ata1 slave  <-> sata0
+ *               ata0 master and slave interfaces brought out
+ *                    on IDE pads
+ * Mode 3: 011 - ata0 master <-> sata0
+ *               ata1 slave  <-> sata1
+ *               ata1 master and slave interfaces brought out
+ *                    on IDE pads
+ */
+#define GEMINI_IDE_IOMUX_MASK			(7 << 24)
+#define GEMINI_IDE_IOMUX_MODE0			(0 << 24)
+#define GEMINI_IDE_IOMUX_MODE1			(1 << 24)
+#define GEMINI_IDE_IOMUX_MODE2			(2 << 24)
+#define GEMINI_IDE_IOMUX_MODE3			(3 << 24)
+#define GEMINI_IDE_IOMUX_SHIFT			(24)
+#define GEMINI_IDE_PADS_ENABLE			BIT(4)
+#define GEMINI_PFLASH_PADS_DISABLE		BIT(1)
+
+/*
+ * Registers directly controlling the PATA<->SATA adapters
+ */
+#define GEMINI_SATA_ID				0x00
+#define GEMINI_SATA_PHY_ID			0x04
+#define GEMINI_SATA0_STATUS			0x08
+#define GEMINI_SATA1_STATUS			0x0c
+#define GEMINI_SATA0_CTRL			0x18
+#define GEMINI_SATA1_CTRL			0x1c
+
+#define GEMINI_SATA_STATUS_BIST_DONE		BIT(5)
+#define GEMINI_SATA_STATUS_BIST_OK		BIT(4)
+#define GEMINI_SATA_STATUS_PHY_READY		BIT(0)
+
+#define GEMINI_SATA_CTRL_PHY_BIST_EN		BIT(14)
+#define GEMINI_SATA_CTRL_PHY_FORCE_IDLE		BIT(13)
+#define GEMINI_SATA_CTRL_PHY_FORCE_READY	BIT(12)
+#define GEMINI_SATA_CTRL_PHY_AFE_LOOP_EN	BIT(10)
+#define GEMINI_SATA_CTRL_PHY_DIG_LOOP_EN	BIT(9)
+#define GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN	BIT(4)
+#define GEMINI_SATA_CTRL_ATAPI_EN		BIT(3)
+#define GEMINI_SATA_CTRL_BUS_WITH_20		BIT(2)
+#define GEMINI_SATA_CTRL_SLAVE_EN		BIT(1)
+#define GEMINI_SATA_CTRL_EN			BIT(0)
+
+/*
+ * There is only ever one instance of this bridge on a system,
+ * so create a singleton so that the FTIDE010 instances can grab
+ * a reference to it.
+ */
+static struct sata_gemini *sg_singleton;
+
+struct sata_gemini *gemini_sata_bridge_get(void)
+{
+	if (sg_singleton)
+		return sg_singleton;
+	return ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL(gemini_sata_bridge_get);
+
+bool gemini_sata_bridge_enabled(struct sata_gemini *sg, bool is_ata1)
+{
+	if (!sg->sata_bridge)
+		return false;
+	/*
+	 * In muxmode 2 and 3 one of the ATA controllers is
+	 * actually not connected to any SATA bridge.
+	 */
+	if ((sg->muxmode == GEMINI_MUXMODE_2) &&
+	    !is_ata1)
+		return false;
+	if ((sg->muxmode == GEMINI_MUXMODE_3) &&
+	    is_ata1)
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL(gemini_sata_bridge_enabled);
+
+enum gemini_muxmode gemini_sata_get_muxmode(struct sata_gemini *sg)
+{
+	return sg->muxmode;
+}
+EXPORT_SYMBOL(gemini_sata_get_muxmode);
+
+static int gemini_sata_setup_bridge(struct sata_gemini *sg,
+				    unsigned int bridge)
+{
+	unsigned long timeout = jiffies + (HZ * 1);
+	bool bridge_online;
+	u32 val;
+
+	if (bridge == 0) {
+		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
+		/* SATA0 slave mode is only used in muxmode 2 */
+		if (sg->muxmode == GEMINI_MUXMODE_2)
+			val |= GEMINI_SATA_CTRL_SLAVE_EN;
+		writel(val, sg->base + GEMINI_SATA0_CTRL);
+	} else {
+		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
+		/* SATA1 slave mode is only used in muxmode 3 */
+		if (sg->muxmode == GEMINI_MUXMODE_3)
+			val |= GEMINI_SATA_CTRL_SLAVE_EN;
+		writel(val, sg->base + GEMINI_SATA1_CTRL);
+	}
+
+	/* Vendor code waits 10 ms here */
+	msleep(10);
+
+	/* Wait for PHY to become ready */
+	do {
+		msleep(100);
+
+		if (bridge == 0)
+			val = readl(sg->base + GEMINI_SATA0_STATUS);
+		else
+			val = readl(sg->base + GEMINI_SATA1_STATUS);
+		if (val & GEMINI_SATA_STATUS_PHY_READY)
+			break;
+	} while (time_before(jiffies, timeout));
+
+	bridge_online = !!(val & GEMINI_SATA_STATUS_PHY_READY);
+
+	dev_info(sg->dev, "SATA%d PHY %s\n", bridge,
+		 bridge_online ? "ready" : "not ready");
+
+	return bridge_online ? 0: -ENODEV;
+}
+
+int gemini_sata_start_bridge(struct sata_gemini *sg, unsigned int bridge)
+{
+	struct clk *pclk;
+	int ret;
+
+	if (bridge == 0)
+		pclk = sg->sata0_pclk;
+	else
+		pclk = sg->sata1_pclk;
+	clk_enable(pclk);
+	msleep(10);
+
+	/* Do not keep clocking a bridge that is not online */
+	ret = gemini_sata_setup_bridge(sg, bridge);
+	if (ret)
+		clk_disable(pclk);
+
+	return ret;
+}
+EXPORT_SYMBOL(gemini_sata_start_bridge);
+
+void gemini_sata_stop_bridge(struct sata_gemini *sg, unsigned int bridge)
+{
+	if (bridge == 0)
+		clk_disable(sg->sata0_pclk);
+	else if (bridge == 1)
+		clk_disable(sg->sata1_pclk);
+}
+EXPORT_SYMBOL(gemini_sata_stop_bridge);
+
+int gemini_sata_reset_bridge(struct sata_gemini *sg,
+			     unsigned int bridge)
+{
+	if (bridge == 0)
+		reset_control_reset(sg->sata0_reset);
+	else
+		reset_control_reset(sg->sata1_reset);
+	msleep(10);
+	return gemini_sata_setup_bridge(sg, bridge);
+}
+EXPORT_SYMBOL(gemini_sata_reset_bridge);
+
+static int gemini_sata_bridge_init(struct sata_gemini *sg)
+{
+	struct device *dev = sg->dev;
+	u32 sata_id, sata_phy_id;
+	int ret;
+
+	sg->sata0_pclk = devm_clk_get(dev, "SATA0_PCLK");
+	if (IS_ERR(sg->sata0_pclk)) {
+		dev_err(dev, "no SATA0 PCLK");
+		return -ENODEV;
+	}
+	sg->sata1_pclk = devm_clk_get(dev, "SATA1_PCLK");
+	if (IS_ERR(sg->sata1_pclk)) {
+		dev_err(dev, "no SATA1 PCLK");
+		return -ENODEV;
+	}
+
+	ret = clk_prepare_enable(sg->sata0_pclk);
+	if (ret) {
+		pr_err("failed to enable SATA0 PCLK\n");
+		return ret;
+	}
+	ret = clk_prepare_enable(sg->sata1_pclk);
+	if (ret) {
+		pr_err("failed to enable SATA1 PCLK\n");
+		clk_disable_unprepare(sg->sata0_pclk);
+		return ret;
+	}
+
+	sg->sata0_reset = devm_reset_control_get(dev, "sata0");
+	if (IS_ERR(sg->sata0_reset)) {
+		dev_err(dev, "no SATA0 reset controller\n");
+		clk_disable_unprepare(sg->sata1_pclk);
+		clk_disable_unprepare(sg->sata0_pclk);
+		return PTR_ERR(sg->sata0_reset);
+	}
+	sg->sata1_reset = devm_reset_control_get(dev, "sata1");
+	if (IS_ERR(sg->sata1_reset)) {
+		dev_err(dev, "no SATA1 reset controller\n");
+		clk_disable_unprepare(sg->sata1_pclk);
+		clk_disable_unprepare(sg->sata0_pclk);
+		return PTR_ERR(sg->sata1_reset);
+	}
+
+	sata_id = readl(sg->base + GEMINI_SATA_ID);
+	sata_phy_id = readl(sg->base + GEMINI_SATA_PHY_ID);
+	sg->sata_bridge = true;
+	clk_disable(sg->sata0_pclk);
+	clk_disable(sg->sata1_pclk);
+
+	dev_info(dev, "SATA ID %08x, PHY ID: %08x\n", sata_id, sata_phy_id);
+
+	return 0;
+}
+
+static int gemini_sata_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct sata_gemini *sg;
+	static struct regmap *map;
+	struct resource *res;
+	enum gemini_muxmode muxmode;
+	u32 gmode;
+	u32 gmask;
+	u32 val;
+	int ret;
+
+	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
+	if (!sg)
+		return -ENOMEM;
+	sg->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	sg->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(sg->base))
+		return PTR_ERR(sg->base);
+
+	map = syscon_regmap_lookup_by_phandle(np, "syscon");
+	if (IS_ERR(map)) {
+		dev_err(dev, "no global syscon\n");
+		return PTR_ERR(map);
+	}
+
+	/* Set up the SATA bridge if need be */
+	if (of_property_read_bool(np, "cortina,gemini-enable-sata-bridge")) {
+		ret = gemini_sata_bridge_init(sg);
+		if (ret)
+			return ret;
+	}
+
+	if (of_property_read_bool(np, "cortina,gemini-enable-ide-pins"))
+		sg->ide_pins = true;
+
+	if (!sg->sata_bridge && !sg->ide_pins) {
+		dev_err(dev, "neither SATA bridge or IDE output enabled\n");
+		ret = -EINVAL;
+		goto out_unprep_clk;
+	}
+
+	ret = of_property_read_u32(np, "cortina,gemini-ata-muxmode", &muxmode);
+	if (ret) {
+		dev_err(dev, "could not parse ATA muxmode\n");
+		goto out_unprep_clk;
+	}
+	if (muxmode > GEMINI_MUXMODE_3) {
+		dev_err(dev, "illegal muxmode %d\n", muxmode);
+		ret = -EINVAL;
+		goto out_unprep_clk;
+	}
+	sg->muxmode = muxmode;
+	gmask = GEMINI_IDE_IOMUX_MASK;
+	gmode = (muxmode << GEMINI_IDE_IOMUX_SHIFT);
+
+	/*
+	 * If we mux out the IDE, parallel flash must be disabled.
+	 * SATA0 and SATA1 have dedicated pins and may coexist with
+	 * parallel flash.
+	 */
+	if (sg->ide_pins)
+		gmode |= GEMINI_IDE_PADS_ENABLE | GEMINI_PFLASH_PADS_DISABLE;
+	else
+		gmask |= GEMINI_IDE_PADS_ENABLE;
+
+	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, gmask, gmode);
+	if (ret) {
+		dev_err(dev, "unable to set up IDE muxing\n");
+		ret = -ENODEV;
+		goto out_unprep_clk;
+	}
+
+	/* FIXME: add more elaborate IDE skew control handling */
+	if (sg->ide_pins) {
+		ret = regmap_read(map, GEMINI_GLOBAL_IDE_SKEW_CTRL, &val);
+		if (ret) {
+			dev_err(dev, "cannot read IDE skew control register\n");
+			return ret;
+		}
+		dev_info(dev, "IDE skew control: %08x\n", val);
+	}
+
+	dev_info(dev, "set up the Gemini IDE/SATA nexus\n");
+	platform_set_drvdata(pdev, sg);
+	sg_singleton = sg;
+
+	return 0;
+
+out_unprep_clk:
+	if (sg->sata_bridge) {
+		clk_unprepare(sg->sata1_pclk);
+		clk_unprepare(sg->sata0_pclk);
+	}
+	return ret;
+}
+
+static int gemini_sata_remove(struct platform_device *pdev)
+{
+	struct sata_gemini *sg = platform_get_drvdata(pdev);
+
+	if (sg->sata_bridge) {
+		clk_unprepare(sg->sata1_pclk);
+		clk_unprepare(sg->sata0_pclk);
+	}
+	sg_singleton = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id gemini_sata_of_match[] = {
+	{
+		.compatible = "cortina,gemini-sata-bridge",
+	},
+	{},
+};
+
+static struct platform_driver gemini_sata_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(gemini_sata_of_match),
+	},
+	.probe = gemini_sata_probe,
+	.remove = gemini_sata_remove,
+};
+module_platform_driver(gemini_sata_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);