Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 472 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c
new file mode 100644
index 000000000..dda6cb848
--- /dev/null
+++ b/drivers/i2c/busses/i2c-xlr.c
@@ -0,0 +1,472 @@
+/*
+ * Copyright 2011, Netlogic Microsystems Inc.
+ * Copyright 2004, Matt Porter <mporter@kernel.crashing.org>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+
+/* XLR I2C REGISTERS */
+#define XLR_I2C_CFG		0x00
+#define XLR_I2C_CLKDIV		0x01
+#define XLR_I2C_DEVADDR		0x02
+#define XLR_I2C_ADDR		0x03
+#define XLR_I2C_DATAOUT		0x04
+#define XLR_I2C_DATAIN		0x05
+#define XLR_I2C_STATUS		0x06
+#define XLR_I2C_STARTXFR	0x07
+#define XLR_I2C_BYTECNT		0x08
+#define XLR_I2C_HDSTATIM	0x09
+
+/* Sigma Designs additional registers */
+#define XLR_I2C_INT_EN		0x09
+#define XLR_I2C_INT_STAT	0x0a
+
+/* XLR I2C REGISTERS FLAGS */
+#define XLR_I2C_BUS_BUSY	0x01
+#define XLR_I2C_SDOEMPTY	0x02
+#define XLR_I2C_RXRDY		0x04
+#define XLR_I2C_ACK_ERR		0x08
+#define XLR_I2C_ARB_STARTERR	0x30
+
+/* Register Values */
+#define XLR_I2C_CFG_ADDR	0xF8
+#define XLR_I2C_CFG_NOADDR	0xFA
+#define XLR_I2C_STARTXFR_ND	0x02    /* No Data */
+#define XLR_I2C_STARTXFR_RD	0x01    /* Read */
+#define XLR_I2C_STARTXFR_WR	0x00    /* Write */
+
+#define XLR_I2C_TIMEOUT		10	/* timeout per byte in msec */
+
+/*
+ * On XLR/XLS, we need to use __raw_ IO to read the I2C registers
+ * because they are in the big-endian MMIO area on the SoC.
+ *
+ * The readl/writel implementation on XLR/XLS byteswaps, because
+ * those are for its little-endian PCI space (see arch/mips/Kconfig).
+ */
+static inline void xlr_i2c_wreg(u32 __iomem *base, unsigned int reg, u32 val)
+{
+	__raw_writel(val, base + reg);
+}
+
+static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned int reg)
+{
+	return __raw_readl(base + reg);
+}
+
+#define XLR_I2C_FLAG_IRQ	1
+
+struct xlr_i2c_config {
+	u32 flags;		/* optional feature support */
+	u32 status_busy;	/* value of STATUS[0] when busy */
+	u32 cfg_extra;		/* extra CFG bits to set */
+};
+
+struct xlr_i2c_private {
+	struct i2c_adapter adap;
+	u32 __iomem *iobase;
+	int irq;
+	int pos;
+	struct i2c_msg *msg;
+	const struct xlr_i2c_config *cfg;
+	wait_queue_head_t wait;
+	struct clk *clk;
+};
+
+static int xlr_i2c_busy(struct xlr_i2c_private *priv, u32 status)
+{
+	return (status & XLR_I2C_BUS_BUSY) == priv->cfg->status_busy;
+}
+
+static int xlr_i2c_idle(struct xlr_i2c_private *priv)
+{
+	return !xlr_i2c_busy(priv, xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS));
+}
+
+static int xlr_i2c_wait(struct xlr_i2c_private *priv, unsigned long timeout)
+{
+	int status;
+	int t;
+
+	t = wait_event_timeout(priv->wait, xlr_i2c_idle(priv),
+				msecs_to_jiffies(timeout));
+	if (!t)
+		return -ETIMEDOUT;
+
+	status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+
+	return status & XLR_I2C_ACK_ERR ? -EIO : 0;
+}
+
+static void xlr_i2c_tx_irq(struct xlr_i2c_private *priv, u32 status)
+{
+	struct i2c_msg *msg = priv->msg;
+
+	if (status & XLR_I2C_SDOEMPTY)
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT,
+				msg->buf[priv->pos++]);
+}
+
+static void xlr_i2c_rx_irq(struct xlr_i2c_private *priv, u32 status)
+{
+	struct i2c_msg *msg = priv->msg;
+
+	if (status & XLR_I2C_RXRDY)
+		msg->buf[priv->pos++] =
+			xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN);
+}
+
+static irqreturn_t xlr_i2c_irq(int irq, void *dev_id)
+{
+	struct xlr_i2c_private *priv = dev_id;
+	struct i2c_msg *msg = priv->msg;
+	u32 int_stat, status;
+
+	int_stat = xlr_i2c_rdreg(priv->iobase, XLR_I2C_INT_STAT);
+	if (!int_stat)
+		return IRQ_NONE;
+
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, int_stat);
+
+	if (!msg)
+		return IRQ_HANDLED;
+
+	status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+
+	if (priv->pos < msg->len) {
+		if (msg->flags & I2C_M_RD)
+			xlr_i2c_rx_irq(priv, status);
+		else
+			xlr_i2c_tx_irq(priv, status);
+	}
+
+	if (!xlr_i2c_busy(priv, status))
+		wake_up(&priv->wait);
+
+	return IRQ_HANDLED;
+}
+
+static int xlr_i2c_tx(struct xlr_i2c_private *priv,  u16 len,
+	u8 *buf, u16 addr)
+{
+	struct i2c_adapter *adap = &priv->adap;
+	unsigned long timeout, stoptime, checktime;
+	u32 i2c_status;
+	int pos, timedout;
+	u8 offset;
+	u32 xfer;
+
+	offset = buf[0];
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
+			XLR_I2C_CFG_ADDR | priv->cfg->cfg_extra);
+
+	timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
+	stoptime = jiffies + timeout;
+	timedout = 0;
+
+	if (len == 1) {
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
+		xfer = XLR_I2C_STARTXFR_ND;
+		pos = 1;
+	} else {
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 2);
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[1]);
+		xfer = XLR_I2C_STARTXFR_WR;
+		pos = 2;
+	}
+
+	priv->pos = pos;
+
+retry:
+	/* retry can only happen on the first byte */
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, xfer);
+
+	if (priv->irq > 0)
+		return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len);
+
+	while (!timedout) {
+		checktime = jiffies;
+		i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+
+		if ((i2c_status & XLR_I2C_SDOEMPTY) && pos < len) {
+			xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos++]);
+
+			/* reset timeout on successful xmit */
+			stoptime = jiffies + timeout;
+		}
+		timedout = time_after(checktime, stoptime);
+
+		if (i2c_status & XLR_I2C_ARB_STARTERR) {
+			if (timedout)
+				break;
+			goto retry;
+		}
+
+		if (i2c_status & XLR_I2C_ACK_ERR)
+			return -EIO;
+
+		if (!xlr_i2c_busy(priv, i2c_status) && pos >= len)
+			return 0;
+	}
+	dev_err(&adap->dev, "I2C transmit timeout\n");
+	return -ETIMEDOUT;
+}
+
+static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr)
+{
+	struct i2c_adapter *adap = &priv->adap;
+	u32 i2c_status;
+	unsigned long timeout, stoptime, checktime;
+	int nbytes, timedout;
+
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
+			XLR_I2C_CFG_NOADDR | priv->cfg->cfg_extra);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
+
+	priv->pos = 0;
+
+	timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
+	stoptime = jiffies + timeout;
+	timedout = 0;
+	nbytes = 0;
+retry:
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD);
+
+	if (priv->irq > 0)
+		return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len);
+
+	while (!timedout) {
+		checktime = jiffies;
+		i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+		if (i2c_status & XLR_I2C_RXRDY) {
+			if (nbytes >= len)
+				return -EIO;	/* should not happen */
+
+			buf[nbytes++] =
+				xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN);
+
+			/* reset timeout on successful read */
+			stoptime = jiffies + timeout;
+		}
+
+		timedout = time_after(checktime, stoptime);
+		if (i2c_status & XLR_I2C_ARB_STARTERR) {
+			if (timedout)
+				break;
+			goto retry;
+		}
+
+		if (i2c_status & XLR_I2C_ACK_ERR)
+			return -EIO;
+
+		if (!xlr_i2c_busy(priv, i2c_status))
+			return 0;
+	}
+
+	dev_err(&adap->dev, "I2C receive timeout\n");
+	return -ETIMEDOUT;
+}
+
+static int xlr_i2c_xfer(struct i2c_adapter *adap,
+	struct i2c_msg *msgs, int num)
+{
+	struct i2c_msg *msg;
+	int i;
+	int ret = 0;
+	struct xlr_i2c_private *priv = i2c_get_adapdata(adap);
+
+	ret = clk_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	if (priv->irq)
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0xf);
+
+
+	for (i = 0; ret == 0 && i < num; i++) {
+		msg = &msgs[i];
+		priv->msg = msg;
+		if (msg->flags & I2C_M_RD)
+			ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0],
+					msg->addr);
+		else
+			ret = xlr_i2c_tx(priv, msg->len, &msg->buf[0],
+					msg->addr);
+	}
+
+	if (priv->irq)
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0);
+
+	clk_disable(priv->clk);
+	priv->msg = NULL;
+
+	return (ret != 0) ? ret : num;
+}
+
+static u32 xlr_func(struct i2c_adapter *adap)
+{
+	/* Emulate SMBUS over I2C */
+	return (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | I2C_FUNC_I2C;
+}
+
+static const struct i2c_algorithm xlr_i2c_algo = {
+	.master_xfer	= xlr_i2c_xfer,
+	.functionality	= xlr_func,
+};
+
+static const struct i2c_adapter_quirks xlr_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
+static const struct xlr_i2c_config xlr_i2c_config_default = {
+	.status_busy	= XLR_I2C_BUS_BUSY,
+	.cfg_extra	= 0,
+};
+
+static const struct xlr_i2c_config xlr_i2c_config_tangox = {
+	.flags		= XLR_I2C_FLAG_IRQ,
+	.status_busy	= 0,
+	.cfg_extra	= 1 << 8,
+};
+
+static const struct of_device_id xlr_i2c_dt_ids[] = {
+	{
+		.compatible	= "sigma,smp8642-i2c",
+		.data		= &xlr_i2c_config_tangox,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, xlr_i2c_dt_ids);
+
+static int xlr_i2c_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct xlr_i2c_private  *priv;
+	struct resource *res;
+	struct clk *clk;
+	unsigned long clk_rate;
+	unsigned long clk_div;
+	u32 busfreq;
+	int irq;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	match = of_match_device(xlr_i2c_dt_ids, &pdev->dev);
+	if (match)
+		priv->cfg = match->data;
+	else
+		priv->cfg = &xlr_i2c_config_default;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->iobase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->iobase))
+		return PTR_ERR(priv->iobase);
+
+	irq = platform_get_irq(pdev, 0);
+
+	if (irq > 0 && (priv->cfg->flags & XLR_I2C_FLAG_IRQ)) {
+		priv->irq = irq;
+
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0);
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, 0xf);
+
+		ret = devm_request_irq(&pdev->dev, priv->irq, xlr_i2c_irq,
+					IRQF_SHARED, dev_name(&pdev->dev),
+					priv);
+		if (ret)
+			return ret;
+
+		init_waitqueue_head(&priv->wait);
+	}
+
+	if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+				 &busfreq))
+		busfreq = 100000;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+
+		clk_rate = clk_get_rate(clk);
+		clk_div = DIV_ROUND_UP(clk_rate, 2 * busfreq);
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_CLKDIV, clk_div);
+
+		clk_disable(clk);
+		priv->clk = clk;
+	}
+
+	priv->adap.dev.parent = &pdev->dev;
+	priv->adap.dev.of_node	= pdev->dev.of_node;
+	priv->adap.owner	= THIS_MODULE;
+	priv->adap.algo_data	= priv;
+	priv->adap.algo		= &xlr_i2c_algo;
+	priv->adap.quirks	= &xlr_i2c_quirks;
+	priv->adap.nr		= pdev->id;
+	priv->adap.class	= I2C_CLASS_HWMON;
+	snprintf(priv->adap.name, sizeof(priv->adap.name), "xlr-i2c");
+
+	i2c_set_adapdata(&priv->adap, priv);
+	ret = i2c_add_numbered_adapter(&priv->adap);
+	if (ret < 0)
+		goto err_unprepare_clk;
+
+	platform_set_drvdata(pdev, priv);
+	dev_info(&priv->adap.dev, "Added I2C Bus.\n");
+	return 0;
+
+err_unprepare_clk:
+	clk_unprepare(clk);
+	return ret;
+}
+
+static int xlr_i2c_remove(struct platform_device *pdev)
+{
+	struct xlr_i2c_private *priv;
+
+	priv = platform_get_drvdata(pdev);
+	i2c_del_adapter(&priv->adap);
+	clk_unprepare(priv->clk);
+
+	return 0;
+}
+
+static struct platform_driver xlr_i2c_driver = {
+	.probe  = xlr_i2c_probe,
+	.remove = xlr_i2c_remove,
+	.driver = {
+		.name   = "xlr-i2cbus",
+		.of_match_table	= xlr_i2c_dt_ids,
+	},
+};
+
+module_platform_driver(xlr_i2c_driver);
+
+MODULE_AUTHOR("Ganesan Ramalingam <ganesanr@netlogicmicro.com>");
+MODULE_DESCRIPTION("XLR/XLS SoC I2C Controller driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:xlr-i2cbus");