diff mbox series

[2/3] fsi: Add ast2600 master driver

Message ID 20191101112905.7282-4-joel@jms.id.au
State Superseded
Headers show
Series fsi: Add AST2600 FSI master | expand

Commit Message

Joel Stanley Nov. 1, 2019, 11:29 a.m. UTC
The ast2600 BMC has a pair of FSI masters in it, behind an AHB to OPB
bridge.

Signed-off-by: Joel Stanley <joel@jms.id.au>

---
 drivers/fsi/Kconfig             |   6 +
 drivers/fsi/Makefile            |   1 +
 drivers/fsi/fsi-master-aspeed.c | 528 ++++++++++++++++++++++++++++++++
 3 files changed, 535 insertions(+)
 create mode 100644 drivers/fsi/fsi-master-aspeed.c

-- 
2.24.0.rc1
diff mbox series

Patch

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index c612db7a914a..12e8c4a04fb1 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -53,6 +53,12 @@  config FSI_MASTER_AST_CF
 	lines driven by the internal ColdFire coprocessor. This requires
 	the corresponding machine specific ColdFire firmware to be available.
 
+config FSI_MASTER_ASPEED
+	tristate "FSI ASPEED master"
+	help
+	 This option enables a FSI master that is present behind an OPB bridge
+	 in the AST2600.
+
 config FSI_SCOM
 	tristate "SCOM FSI client device driver"
 	---help---
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index e4a2ff043c32..da218a1ad8e1 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -2,6 +2,7 @@ 
 
 obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
+obj-$(CONFIG_FSI_MASTER_ASPEED) += fsi-master-aspeed.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_MASTER_AST_CF) += fsi-master-ast-cf.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
new file mode 100644
index 000000000000..5bb7a778075e
--- /dev/null
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -0,0 +1,528 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (C) IBM Corporation 2018
+// FSI master driver for AST2600
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/fsi.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/iopoll.h>
+
+#include "fsi-master.h"
+
+struct fsi_master_aspeed {
+	struct fsi_master	master;
+	struct device		*dev;
+	void __iomem		*base;
+	struct clk		*clk;
+};
+
+#define to_fsi_master_aspeed(m) \
+	container_of(m, struct fsi_master_aspeed, master)
+
+/* Control register (size 0x400) */
+static const u32 ctrl_base = 0x80000000;
+
+static const u32 fsi_base = 0xa0000000;
+
+#define OPB_FSI_VER	0x00
+#define OPB_TRIGGER	0x04
+#define OPB_CTRL_BASE	0x08
+#define OPB_FSI_BASE	0x0c
+#define OPB_CLK_SYNC	0x3c
+#define OPB_IRQ_CLEAR	0x40
+#define OPB_IRQ_MASK	0x44
+#define OPB_IRQ_STATUS	0x48
+
+#define OPB0_SELECT	0x10
+#define OPB0_RW		0x14
+#define OPB0_XFER_SIZE	0x18
+#define OPB0_FSI_ADDR	0x1c
+#define OPB0_FSI_DATA_W	0x20
+#define OPB0_STATUS	0x80
+#define  STATUS_HALFWORD_ACK	BIT(0)
+#define  STATUS_FULLWORD_ACK	BIT(1)
+#define  STATUS_ERR_ACK		BIT(2)
+#define OPB0_FSI_DATA_R	0x84
+
+#define OPB0_W_ENDIAN	0x4c
+#define OPB0_R_ENDIAN	0x5c
+
+/* OPB_IRQ_MASK */
+#define OPB1_XFER_ACK_EN BIT(17)
+#define OPB0_XFER_ACK_EN BIT(16)
+
+/* OPB_RW */
+#define CMD_READ	BIT(0)
+#define CMD_WRITE	0
+
+/* OPBx_XFER_SIZE */
+#define XFER_FULLWORD	(BIT(1) | BIT(0))
+#define XFER_HALFWORD	(BIT(0))
+#define XFER_BYTE	(0)
+
+#define FSI_LINK_ENABLE_SETUP_TIME	10	/* in mS */
+
+#define DEFAULT_DIVISOR			14
+#define OPB_POLL_TIMEOUT		10000
+
+static int __opb_write(struct fsi_master_aspeed *aspeed, u32 addr,
+		       u32 val, u32 transfer_size)
+{
+	void __iomem *base = aspeed->base;
+	u32 reg, status;
+	int ret;
+
+	writel(CMD_WRITE, base + OPB0_RW);
+	writel(transfer_size, base + OPB0_XFER_SIZE);
+	writel(addr, base + OPB0_FSI_ADDR);
+	writel(val, base + OPB0_FSI_DATA_W);
+	writel(0x1, base + OPB_IRQ_CLEAR);
+	writel(0x1, base + OPB_TRIGGER);
+
+	ret = readl_poll_timeout(base + OPB_IRQ_STATUS, reg,
+				(reg & OPB0_XFER_ACK_EN) != 0,
+				0, OPB_POLL_TIMEOUT);
+
+	status = readl(base + OPB0_STATUS);
+
+	/* Return error when poll timed out */
+	if (ret)
+		return ret;
+
+	/* Command failed, master will reset */
+	if (status & STATUS_ERR_ACK)
+		return -EIO;
+
+	return 0;
+}
+
+static int opb_writeb(struct fsi_master_aspeed *aspeed, u32 addr, u8 val)
+{
+	return __opb_write(aspeed, addr, val, XFER_BYTE);
+}
+
+static int opb_writew(struct fsi_master_aspeed *aspeed, u32 addr, __be16 val)
+{
+	return __opb_write(aspeed, addr, (__force u16)val, XFER_HALFWORD);
+}
+
+static int opb_writel(struct fsi_master_aspeed *aspeed, u32 addr, __be32 val)
+{
+	return __opb_write(aspeed, addr, (__force u32)val, XFER_FULLWORD);
+}
+
+static int __opb_read(struct fsi_master_aspeed *aspeed, uint32_t addr,
+		      u32 transfer_size, void *out)
+{
+	void __iomem *base = aspeed->base;
+	u32 result, reg;
+	int status, ret;
+
+	writel(CMD_READ, base + OPB0_RW);
+	writel(transfer_size, base + OPB0_XFER_SIZE);
+	writel(addr, base + OPB0_FSI_ADDR);
+	writel(0x1, base + OPB_IRQ_CLEAR);
+	writel(0x1, base + OPB_TRIGGER);
+
+	ret = readl_poll_timeout(base + OPB_IRQ_STATUS, reg,
+			   (reg & OPB0_XFER_ACK_EN) != 0,
+			   0, OPB_POLL_TIMEOUT);
+
+	status = readl(base + OPB0_STATUS);
+
+	result = readl(base + OPB0_FSI_DATA_R);
+
+	/* Return error when poll timed out */
+	if (ret)
+		return ret;
+
+	/* Command failed, master will reset */
+	if (status & STATUS_ERR_ACK)
+		return -EIO;
+
+	if (out) {
+		switch (transfer_size) {
+		case XFER_BYTE:
+			*(u8 *)out = result;
+			break;
+		case XFER_HALFWORD:
+			*(u16 *)out = result;
+			break;
+		case XFER_FULLWORD:
+			*(u32 *)out = result;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+	}
+
+	return 0;
+}
+
+static int opb_readl(struct fsi_master_aspeed *aspeed, uint32_t addr, __be32 *out)
+{
+	return __opb_read(aspeed, addr, XFER_FULLWORD, out);
+}
+
+static int opb_readw(struct fsi_master_aspeed *aspeed, uint32_t addr, __be16 *out)
+{
+	return __opb_read(aspeed, addr, XFER_HALFWORD, (void *)out);
+}
+
+static int opb_readb(struct fsi_master_aspeed *aspeed, uint32_t addr, u8 *out)
+{
+	return __opb_read(aspeed, addr, XFER_BYTE, (void *)out);
+}
+
+static int check_errors(struct fsi_master_aspeed *aspeed, int err)
+{
+	int ret;
+
+	if (err == -EIO) {
+		/* Check MAEB (0x70) ? */
+
+		/* Then clear errors in master */
+		ret = opb_writel(aspeed, ctrl_base + FSI_MRESP0,
+				cpu_to_be32(FSI_MRESP_RST_ALL_MASTER));
+		if (ret) {
+			/* TODO: log? return different code? */
+			return ret;
+		}
+		/* TODO: confirm that 0x70 was okay */
+	}
+
+	/* This will pass through timeout errors */
+	return err;
+}
+
+static int aspeed_master_read(struct fsi_master *master, int link,
+			uint8_t id, uint32_t addr, void *val, size_t size)
+{
+	struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+	int ret;
+
+	if (id != 0)
+		return -EINVAL;
+
+	addr += link * FSI_HUB_LINK_SIZE;
+
+	switch (size) {
+	case 1:
+		ret = opb_readb(aspeed, fsi_base + addr, val);
+		break;
+	case 2:
+		ret = opb_readw(aspeed, fsi_base + addr, val);
+		break;
+	case 4:
+		ret = opb_readl(aspeed, fsi_base + addr, val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = check_errors(aspeed, ret);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int aspeed_master_write(struct fsi_master *master, int link,
+			uint8_t id, uint32_t addr, const void *val, size_t size)
+{
+	struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+	int ret;
+
+	if (id != 0)
+		return -EINVAL;
+
+	addr += link * FSI_HUB_LINK_SIZE;
+
+	switch (size) {
+	case 1:
+		ret = opb_writeb(aspeed, fsi_base + addr, *(u8 *)val);
+		break;
+	case 2:
+		ret = opb_writew(aspeed, fsi_base + addr, *(__be16 *)val);
+		break;
+	case 4:
+		ret = opb_writel(aspeed, fsi_base + addr, *(__be32 *)val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = check_errors(aspeed, ret);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int aspeed_master_link_enable(struct fsi_master *master, int link)
+{
+	struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+	int idx, bit, ret;
+	__be32 reg, result;
+
+	idx = link / 32;
+	bit = link % 32;
+
+	reg = cpu_to_be32(0x80000000 >> bit);
+
+	ret = opb_writel(aspeed, ctrl_base + FSI_MSENP0 + (4 * idx), reg);
+	if (ret)
+		return ret;
+
+	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
+
+	ret = opb_readl(aspeed, ctrl_base + FSI_MENP0 + (4 * idx), &result);
+	if (ret)
+		return ret;
+
+	if (result != reg) {
+		dev_err(aspeed->dev, "%s failed: %08x\n", __func__, result);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int aspeed_master_term(struct fsi_master *master, int link, uint8_t id)
+{
+	struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+	uint32_t addr;
+	__be32 cmd;
+	int rc;
+
+	addr = 0x4;
+	cmd = cpu_to_be32(0xecc00000);
+
+	dev_dbg(aspeed->dev, "sending term to link %d slave %d\n", link, id);
+
+	rc = aspeed_master_write(master, link, id, addr, &cmd, 4);
+
+	dev_dbg(aspeed->dev, "term done (%d)\n", rc);
+
+	return rc;
+}
+
+static int aspeed_master_break(struct fsi_master *master, int link)
+{
+	struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+	uint32_t addr;
+	__be32 cmd;
+	int rc;
+
+	addr = 0x0;
+	cmd = cpu_to_be32(0xc0de0000);
+
+	dev_dbg(aspeed->dev, "sending break to link %d\n", link);
+
+	rc = aspeed_master_write(master, link, 0, addr, &cmd, 4);
+
+	dev_dbg(aspeed->dev, "break done (%d)\n", rc);
+
+	return rc;
+}
+
+static void aspeed_master_release(struct device *dev)
+{
+	struct fsi_master_aspeed *aspeed =
+		to_fsi_master_aspeed(dev_to_fsi_master(dev));
+
+	kfree(aspeed);
+}
+
+/* mmode encoders */
+static inline u32 fsi_mmode_crs0(u32 x)
+{
+	return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT;
+}
+
+static inline u32 fsi_mmode_crs1(u32 x)
+{
+	return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT;
+}
+
+static int aspeed_master_init(struct fsi_master_aspeed *aspeed)
+{
+	__be32 reg;
+
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
+			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
+	opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg);
+
+	/* Initialize the MFSI (hub master) engine */
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
+			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
+	opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg);
+
+	reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM);
+	opb_writel(aspeed, ctrl_base + FSI_MECTRL, reg);
+
+	reg = cpu_to_be32(FSI_MMODE_ECRC | FSI_MMODE_EPC | FSI_MMODE_RELA
+			| fsi_mmode_crs0(DEFAULT_DIVISOR)
+			| fsi_mmode_crs1(DEFAULT_DIVISOR)
+			| FSI_MMODE_P8_TO_LSB);
+	opb_writel(aspeed, ctrl_base + FSI_MMODE, reg);
+
+	reg = cpu_to_be32(0xffff0000);
+	opb_writel(aspeed, ctrl_base + FSI_MDLYR, reg);
+
+	reg = cpu_to_be32(~0);
+	opb_writel(aspeed, ctrl_base + FSI_MSENP0, reg);
+
+	/* Leave enabled long enough for master logic to set up */
+	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
+
+	opb_writel(aspeed, ctrl_base + FSI_MCENP0, reg);
+
+	opb_readl(aspeed, ctrl_base + FSI_MAEB, NULL);
+
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK);
+	opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg);
+
+	opb_readl(aspeed, ctrl_base + FSI_MLEVP0, NULL);
+
+	/* Reset the master bridge */
+	reg = cpu_to_be32(FSI_MRESB_RST_GEN);
+	opb_writel(aspeed, ctrl_base + FSI_MRESB0, reg);
+
+	reg = cpu_to_be32(FSI_MRESB_RST_ERR);
+	opb_writel(aspeed, ctrl_base + FSI_MRESB0, reg);
+
+	return 0;
+}
+
+static int fsi_master_aspeed_probe(struct platform_device *pdev)
+{
+	struct fsi_master_aspeed *aspeed;
+	struct resource *res;
+	int rc, links, reg;
+	__be32 raw;
+
+	aspeed = devm_kzalloc(&pdev->dev, sizeof(*aspeed), GFP_KERNEL);
+	if (!aspeed)
+		return -ENOMEM;
+
+	aspeed->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	aspeed->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(aspeed->base))
+		return PTR_ERR(aspeed->base);
+
+	aspeed->clk = devm_clk_get(aspeed->dev, NULL);
+	if (IS_ERR(aspeed->clk)) {
+		dev_err(aspeed->dev, "couldn't get clock\n");
+		return PTR_ERR(aspeed->clk);
+	}
+	rc = clk_prepare_enable(aspeed->clk);
+	if (rc) {
+		dev_err(aspeed->dev, "couldn't enable clock\n");
+		return rc;
+	}
+
+	writel(0x1, aspeed->base + OPB_CLK_SYNC);
+	writel(OPB1_XFER_ACK_EN | OPB0_XFER_ACK_EN,
+			aspeed->base + OPB_IRQ_MASK);
+	/* TODO: Try without this */
+	writel(0x10, aspeed->base + 0x64); // Retry counter number ???
+	writel(0x0f, aspeed->base + 0xe4); // DMA Enable
+
+	writel(ctrl_base, aspeed->base + OPB_CTRL_BASE);
+	writel(fsi_base, aspeed->base + OPB_FSI_BASE);
+
+	/* Set read data order */
+	writel(0x0011bb1b, aspeed->base + OPB0_R_ENDIAN);
+
+	/* Set write data order */
+	writel(0x0011bb1b, aspeed->base + OPB0_W_ENDIAN);
+	writel(0xffaa5500, aspeed->base + 0x50);
+
+	/*
+	 * Select OPB0 for all operations.
+	 * Will need to be reworked when enabling DMA or anything that uses
+	 * OPB1.
+	 */
+	writel(0x1, aspeed->base + OPB0_SELECT);
+
+	rc = opb_readl(aspeed, ctrl_base + FSI_MVER, &raw);
+	if (rc) {
+		dev_err(&pdev->dev, "failed to read hub version\n");
+		return rc;
+	}
+
+	reg = be32_to_cpu(raw);
+	links = (reg >> 8) & 0xff;
+	dev_info(&pdev->dev, "hub version %08x (%d links)\n", reg, links);
+
+	aspeed->master.dev.parent = &pdev->dev;
+	aspeed->master.dev.release = aspeed_master_release;
+	aspeed->master.dev.of_node = of_node_get(dev_of_node(&pdev->dev));
+
+	aspeed->master.n_links = links;
+	aspeed->master.read = aspeed_master_read;
+	aspeed->master.write = aspeed_master_write;
+	aspeed->master.send_break = aspeed_master_break;
+	aspeed->master.term = aspeed_master_term;
+	aspeed->master.link_enable = aspeed_master_link_enable;
+
+	dev_set_drvdata(&pdev->dev, aspeed);
+
+	aspeed_master_init(aspeed);
+
+	rc = fsi_master_register(&aspeed->master);
+	if (rc)
+		goto err_release;
+
+	/* At this point, fsi_master_register performs the device_initialize(),
+	 * and holds the sole reference on master.dev. This means the device
+	 * will be freed (via ->release) during any subsequent call to
+	 * fsi_master_unregister.  We add our own reference to it here, so we
+	 * can perform cleanup (in _remove()) without it being freed before
+	 * we're ready.
+	 */
+	get_device(&aspeed->master.dev);
+	return 0;
+
+err_release:
+	clk_disable_unprepare(aspeed->clk);
+	return rc;
+}
+
+static int fsi_master_aspeed_remove(struct platform_device *pdev)
+{
+	struct fsi_master_aspeed *aspeed = platform_get_drvdata(pdev);
+
+	fsi_master_unregister(&aspeed->master);
+	clk_disable_unprepare(aspeed->clk);
+
+	return 0;
+}
+
+static const struct of_device_id fsi_master_aspeed_match[] = {
+	{ .compatible = "aspeed,ast2600-fsi-master" },
+	{ },
+};
+
+static struct platform_driver fsi_master_aspeed_driver = {
+	.driver = {
+		.name		= "fsi-master-aspeed",
+		.of_match_table	= fsi_master_aspeed_match,
+	},
+	.probe	= fsi_master_aspeed_probe,
+	.remove = fsi_master_aspeed_remove,
+};
+
+module_platform_driver(fsi_master_aspeed_driver);
+MODULE_LICENSE("GPL");