File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/media/pci/pt3/pt3_i2c.c b/drivers/media/pci/pt3/pt3_i2c.c
new file mode 100644
index 0000000..ec6a8a2
--- /dev/null
+++ b/drivers/media/pci/pt3/pt3_i2c.c
@@ -0,0 +1,240 @@
+/*
+ * Earthsoft PT3 driver
+ *
+ * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
+ *
+ * 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 version 2.
+ *
+ *
+ * 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/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/pci.h>
+
+#include "pt3.h"
+
+#define PT3_I2C_BASE  2048
+#define PT3_CMD_ADDR_NORMAL 0
+#define PT3_CMD_ADDR_INIT_DEMOD  4096
+#define PT3_CMD_ADDR_INIT_TUNER  (4096 + 2042)
+
+/* masks for I2C status register */
+#define STAT_SEQ_RUNNING 0x1
+#define STAT_SEQ_ERROR   0x6
+#define STAT_NO_SEQ      0x8
+
+#define PT3_I2C_RUN   (1 << 16)
+#define PT3_I2C_RESET (1 << 17)
+
+enum ctl_cmd {
+	I_END,
+	I_ADDRESS,
+	I_CLOCK_L,
+	I_CLOCK_H,
+	I_DATA_L,
+	I_DATA_H,
+	I_RESET,
+	I_SLEEP,
+	I_DATA_L_NOP  = 0x08,
+	I_DATA_H_NOP  = 0x0c,
+	I_DATA_H_READ = 0x0d,
+	I_DATA_H_ACK0 = 0x0e,
+	I_DATA_H_ACK1 = 0x0f,
+};
+
+
+static void cmdbuf_add(struct pt3_i2cbuf *cbuf, enum ctl_cmd cmd)
+{
+	int buf_idx;
+
+	if ((cbuf->num_cmds % 2) == 0)
+		cbuf->tmp = cmd;
+	else {
+		cbuf->tmp |= cmd << 4;
+		buf_idx = cbuf->num_cmds / 2;
+		if (buf_idx < ARRAY_SIZE(cbuf->data))
+			cbuf->data[buf_idx] = cbuf->tmp;
+	}
+	cbuf->num_cmds++;
+}
+
+static void put_end(struct pt3_i2cbuf *cbuf)
+{
+	cmdbuf_add(cbuf, I_END);
+	if (cbuf->num_cmds % 2)
+		cmdbuf_add(cbuf, I_END);
+}
+
+static void put_start(struct pt3_i2cbuf *cbuf)
+{
+	cmdbuf_add(cbuf, I_DATA_H);
+	cmdbuf_add(cbuf, I_CLOCK_H);
+	cmdbuf_add(cbuf, I_DATA_L);
+	cmdbuf_add(cbuf, I_CLOCK_L);
+}
+
+static void put_byte_write(struct pt3_i2cbuf *cbuf, u8 val)
+{
+	u8 mask;
+
+	mask = 0x80;
+	for (mask = 0x80; mask > 0; mask >>= 1)
+		cmdbuf_add(cbuf, (val & mask) ? I_DATA_H_NOP : I_DATA_L_NOP);
+	cmdbuf_add(cbuf, I_DATA_H_ACK0);
+}
+
+static void put_byte_read(struct pt3_i2cbuf *cbuf, u32 size)
+{
+	int i, j;
+
+	for (i = 0; i < size; i++) {
+		for (j = 0; j < 8; j++)
+			cmdbuf_add(cbuf, I_DATA_H_READ);
+		cmdbuf_add(cbuf, (i == size - 1) ? I_DATA_H_NOP : I_DATA_L_NOP);
+	}
+}
+
+static void put_stop(struct pt3_i2cbuf *cbuf)
+{
+	cmdbuf_add(cbuf, I_DATA_L);
+	cmdbuf_add(cbuf, I_CLOCK_H);
+	cmdbuf_add(cbuf, I_DATA_H);
+}
+
+
+/* translates msgs to internal commands for bit-banging */
+static void translate(struct pt3_i2cbuf *cbuf, struct i2c_msg *msgs, int num)
+{
+	int i, j;
+	bool rd;
+
+	cbuf->num_cmds = 0;
+	for (i = 0; i < num; i++) {
+		rd = !!(msgs[i].flags & I2C_M_RD);
+		put_start(cbuf);
+		put_byte_write(cbuf, msgs[i].addr << 1 | rd);
+		if (rd)
+			put_byte_read(cbuf, msgs[i].len);
+		else
+			for (j = 0; j < msgs[i].len; j++)
+				put_byte_write(cbuf, msgs[i].buf[j]);
+	}
+	if (num > 0) {
+		put_stop(cbuf);
+		put_end(cbuf);
+	}
+}
+
+static int wait_i2c_result(struct pt3_board *pt3, u32 *result, int max_wait)
+{
+	int i;
+	u32 v;
+
+	for (i = 0; i < max_wait; i++) {
+		v = ioread32(pt3->regs[0] + REG_I2C_R);
+		if (!(v & STAT_SEQ_RUNNING))
+			break;
+		usleep_range(500, 750);
+	}
+	if (i >= max_wait)
+		return -EIO;
+	if (result)
+		*result = v;
+	return 0;
+}
+
+/* send [pre-]translated i2c msgs stored at addr */
+static int send_i2c_cmd(struct pt3_board *pt3, u32 addr)
+{
+	u32 ret;
+
+	/* make sure that previous transactions had finished */
+	if (wait_i2c_result(pt3, NULL, 50)) {
+		dev_warn(&pt3->pdev->dev, "(%s) prev. transaction stalled\n",
+				__func__);
+		return -EIO;
+	}
+
+	iowrite32(PT3_I2C_RUN | addr, pt3->regs[0] + REG_I2C_W);
+	usleep_range(200, 300);
+	/* wait for the current transaction to finish */
+	if (wait_i2c_result(pt3, &ret, 500) || (ret & STAT_SEQ_ERROR)) {
+		dev_warn(&pt3->pdev->dev, "(%s) failed.\n", __func__);
+		return -EIO;
+	}
+	return 0;
+}
+
+
+/* init commands for each demod are combined into one transaction
+ *  and hidden in ROM with the address PT3_CMD_ADDR_INIT_DEMOD.
+ */
+int  pt3_init_all_demods(struct pt3_board *pt3)
+{
+	ioread32(pt3->regs[0] + REG_I2C_R);
+	return send_i2c_cmd(pt3, PT3_CMD_ADDR_INIT_DEMOD);
+}
+
+/* init commands for two ISDB-T tuners are hidden in ROM. */
+int  pt3_init_all_mxl301rf(struct pt3_board *pt3)
+{
+	usleep_range(1000, 2000);
+	return send_i2c_cmd(pt3, PT3_CMD_ADDR_INIT_TUNER);
+}
+
+void pt3_i2c_reset(struct pt3_board *pt3)
+{
+	iowrite32(PT3_I2C_RESET, pt3->regs[0] + REG_I2C_W);
+}
+
+/*
+ * I2C algorithm
+ */
+int
+pt3_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct pt3_board *pt3;
+	struct pt3_i2cbuf *cbuf;
+	int i;
+	void __iomem *p;
+
+	pt3 = i2c_get_adapdata(adap);
+	cbuf = pt3->i2c_buf;
+
+	for (i = 0; i < num; i++)
+		if (msgs[i].flags & I2C_M_RECV_LEN) {
+			dev_warn(&pt3->pdev->dev,
+				"(%s) I2C_M_RECV_LEN not supported.\n",
+				__func__);
+			return -EINVAL;
+		}
+
+	translate(cbuf, msgs, num);
+	memcpy_toio(pt3->regs[1] + PT3_I2C_BASE + PT3_CMD_ADDR_NORMAL / 2,
+			cbuf->data, cbuf->num_cmds);
+
+	if (send_i2c_cmd(pt3, PT3_CMD_ADDR_NORMAL) < 0)
+		return -EIO;
+
+	p = pt3->regs[1] + PT3_I2C_BASE;
+	for (i = 0; i < num; i++)
+		if ((msgs[i].flags & I2C_M_RD) && msgs[i].len > 0) {
+			memcpy_fromio(msgs[i].buf, p, msgs[i].len);
+			p += msgs[i].len;
+		}
+
+	return num;
+}
+
+u32 pt3_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C;
+}