1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Earthsoft PT3 driver
4 *
5 * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
6 */
7#include <linux/delay.h>
8#include <linux/device.h>
9#include <linux/i2c.h>
10#include <linux/io.h>
11#include <linux/pci.h>
12
13#include "pt3.h"
14
15#define PT3_I2C_BASE  2048
16#define PT3_CMD_ADDR_NORMAL 0
17#define PT3_CMD_ADDR_INIT_DEMOD  4096
18#define PT3_CMD_ADDR_INIT_TUNER  (4096 + 2042)
19
20/* masks for I2C status register */
21#define STAT_SEQ_RUNNING 0x1
22#define STAT_SEQ_ERROR   0x6
23#define STAT_NO_SEQ      0x8
24
25#define PT3_I2C_RUN   (1 << 16)
26#define PT3_I2C_RESET (1 << 17)
27
28enum ctl_cmd {
29	I_END,
30	I_ADDRESS,
31	I_CLOCK_L,
32	I_CLOCK_H,
33	I_DATA_L,
34	I_DATA_H,
35	I_RESET,
36	I_SLEEP,
37	I_DATA_L_NOP  = 0x08,
38	I_DATA_H_NOP  = 0x0c,
39	I_DATA_H_READ = 0x0d,
40	I_DATA_H_ACK0 = 0x0e,
41	I_DATA_H_ACK1 = 0x0f,
42};
43
44
45static void cmdbuf_add(struct pt3_i2cbuf *cbuf, enum ctl_cmd cmd)
46{
47	int buf_idx;
48
49	if ((cbuf->num_cmds % 2) == 0)
50		cbuf->tmp = cmd;
51	else {
52		cbuf->tmp |= cmd << 4;
53		buf_idx = cbuf->num_cmds / 2;
54		if (buf_idx < ARRAY_SIZE(cbuf->data))
55			cbuf->data[buf_idx] = cbuf->tmp;
56	}
57	cbuf->num_cmds++;
58}
59
60static void put_end(struct pt3_i2cbuf *cbuf)
61{
62	cmdbuf_add(cbuf, I_END);
63	if (cbuf->num_cmds % 2)
64		cmdbuf_add(cbuf, I_END);
65}
66
67static void put_start(struct pt3_i2cbuf *cbuf)
68{
69	cmdbuf_add(cbuf, I_DATA_H);
70	cmdbuf_add(cbuf, I_CLOCK_H);
71	cmdbuf_add(cbuf, I_DATA_L);
72	cmdbuf_add(cbuf, I_CLOCK_L);
73}
74
75static void put_byte_write(struct pt3_i2cbuf *cbuf, u8 val)
76{
77	u8 mask;
78
79	for (mask = 0x80; mask > 0; mask >>= 1)
80		cmdbuf_add(cbuf, (val & mask) ? I_DATA_H_NOP : I_DATA_L_NOP);
81	cmdbuf_add(cbuf, I_DATA_H_ACK0);
82}
83
84static void put_byte_read(struct pt3_i2cbuf *cbuf, u32 size)
85{
86	int i, j;
87
88	for (i = 0; i < size; i++) {
89		for (j = 0; j < 8; j++)
90			cmdbuf_add(cbuf, I_DATA_H_READ);
91		cmdbuf_add(cbuf, (i == size - 1) ? I_DATA_H_NOP : I_DATA_L_NOP);
92	}
93}
94
95static void put_stop(struct pt3_i2cbuf *cbuf)
96{
97	cmdbuf_add(cbuf, I_DATA_L);
98	cmdbuf_add(cbuf, I_CLOCK_H);
99	cmdbuf_add(cbuf, I_DATA_H);
100}
101
102
103/* translates msgs to internal commands for bit-banging */
104static void translate(struct pt3_i2cbuf *cbuf, struct i2c_msg *msgs, int num)
105{
106	int i, j;
107	bool rd;
108
109	cbuf->num_cmds = 0;
110	for (i = 0; i < num; i++) {
111		rd = !!(msgs[i].flags & I2C_M_RD);
112		put_start(cbuf);
113		put_byte_write(cbuf, msgs[i].addr << 1 | rd);
114		if (rd)
115			put_byte_read(cbuf, msgs[i].len);
116		else
117			for (j = 0; j < msgs[i].len; j++)
118				put_byte_write(cbuf, msgs[i].buf[j]);
119	}
120	if (num > 0) {
121		put_stop(cbuf);
122		put_end(cbuf);
123	}
124}
125
126static int wait_i2c_result(struct pt3_board *pt3, u32 *result, int max_wait)
127{
128	int i;
129	u32 v;
130
131	for (i = 0; i < max_wait; i++) {
132		v = ioread32(pt3->regs[0] + REG_I2C_R);
133		if (!(v & STAT_SEQ_RUNNING))
134			break;
135		usleep_range(500, 750);
136	}
137	if (i >= max_wait)
138		return -EIO;
139	if (result)
140		*result = v;
141	return 0;
142}
143
144/* send [pre-]translated i2c msgs stored at addr */
145static int send_i2c_cmd(struct pt3_board *pt3, u32 addr)
146{
147	u32 ret;
148
149	/* make sure that previous transactions had finished */
150	if (wait_i2c_result(pt3, NULL, 50)) {
151		dev_warn(&pt3->pdev->dev, "(%s) prev. transaction stalled\n",
152				__func__);
153		return -EIO;
154	}
155
156	iowrite32(PT3_I2C_RUN | addr, pt3->regs[0] + REG_I2C_W);
157	usleep_range(200, 300);
158	/* wait for the current transaction to finish */
159	if (wait_i2c_result(pt3, &ret, 500) || (ret & STAT_SEQ_ERROR)) {
160		dev_warn(&pt3->pdev->dev, "(%s) failed.\n", __func__);
161		return -EIO;
162	}
163	return 0;
164}
165
166
167/* init commands for each demod are combined into one transaction
168 *  and hidden in ROM with the address PT3_CMD_ADDR_INIT_DEMOD.
169 */
170int  pt3_init_all_demods(struct pt3_board *pt3)
171{
172	ioread32(pt3->regs[0] + REG_I2C_R);
173	return send_i2c_cmd(pt3, PT3_CMD_ADDR_INIT_DEMOD);
174}
175
176/* init commands for two ISDB-T tuners are hidden in ROM. */
177int  pt3_init_all_mxl301rf(struct pt3_board *pt3)
178{
179	usleep_range(1000, 2000);
180	return send_i2c_cmd(pt3, PT3_CMD_ADDR_INIT_TUNER);
181}
182
183void pt3_i2c_reset(struct pt3_board *pt3)
184{
185	iowrite32(PT3_I2C_RESET, pt3->regs[0] + REG_I2C_W);
186}
187
188/*
189 * I2C algorithm
190 */
191int
192pt3_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
193{
194	struct pt3_board *pt3;
195	struct pt3_i2cbuf *cbuf;
196	int i;
197	void __iomem *p;
198
199	pt3 = i2c_get_adapdata(adap);
200	cbuf = pt3->i2c_buf;
201
202	for (i = 0; i < num; i++)
203		if (msgs[i].flags & I2C_M_RECV_LEN) {
204			dev_warn(&pt3->pdev->dev,
205				"(%s) I2C_M_RECV_LEN not supported.\n",
206				__func__);
207			return -EINVAL;
208		}
209
210	translate(cbuf, msgs, num);
211	memcpy_toio(pt3->regs[1] + PT3_I2C_BASE + PT3_CMD_ADDR_NORMAL / 2,
212			cbuf->data, cbuf->num_cmds);
213
214	if (send_i2c_cmd(pt3, PT3_CMD_ADDR_NORMAL) < 0)
215		return -EIO;
216
217	p = pt3->regs[1] + PT3_I2C_BASE;
218	for (i = 0; i < num; i++)
219		if ((msgs[i].flags & I2C_M_RD) && msgs[i].len > 0) {
220			memcpy_fromio(msgs[i].buf, p, msgs[i].len);
221			p += msgs[i].len;
222		}
223
224	return num;
225}
226
227u32 pt3_i2c_functionality(struct i2c_adapter *adap)
228{
229	return I2C_FUNC_I2C;
230}
231