1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for Silicon Labs C8051F300 microcontroller.
4 *
5 * It is used for LNB power control in TeVii S470,
6 * TBS 6920 PCIe DVB-S2 cards.
7 *
8 * Microcontroller connected to cx23885 GPIO pins:
9 * GPIO0 - data		- P0.3 F300
10 * GPIO1 - reset	- P0.2 F300
11 * GPIO2 - clk		- P0.1 F300
12 * GPIO3 - busy		- P0.0 F300
13 *
14 * Copyright (C) 2009 Igor M. Liplianin <liplianin@me.by>
15 */
16
17#include "cx23885.h"
18#include "cx23885-f300.h"
19
20#define F300_DATA	GPIO_0
21#define F300_RESET	GPIO_1
22#define F300_CLK	GPIO_2
23#define F300_BUSY	GPIO_3
24
25static void f300_set_line(struct cx23885_dev *dev, u32 line, u8 lvl)
26{
27	cx23885_gpio_enable(dev, line, 1);
28	if (lvl == 1)
29		cx23885_gpio_set(dev, line);
30	else
31		cx23885_gpio_clear(dev, line);
32}
33
34static u8 f300_get_line(struct cx23885_dev *dev, u32 line)
35{
36	cx23885_gpio_enable(dev, line, 0);
37
38	return cx23885_gpio_get(dev, line);
39}
40
41static void f300_send_byte(struct cx23885_dev *dev, u8 dta)
42{
43	u8 i;
44
45	for (i = 0; i < 8; i++) {
46		f300_set_line(dev, F300_CLK, 0);
47		udelay(30);
48		f300_set_line(dev, F300_DATA, (dta & 0x80) >> 7);/* msb first */
49		udelay(30);
50		dta <<= 1;
51		f300_set_line(dev, F300_CLK, 1);
52		udelay(30);
53	}
54}
55
56static u8 f300_get_byte(struct cx23885_dev *dev)
57{
58	u8 i, dta = 0;
59
60	for (i = 0; i < 8; i++) {
61		f300_set_line(dev, F300_CLK, 0);
62		udelay(30);
63		dta <<= 1;
64		f300_set_line(dev, F300_CLK, 1);
65		udelay(30);
66		dta |= f300_get_line(dev, F300_DATA);/* msb first */
67
68	}
69
70	return dta;
71}
72
73static u8 f300_xfer(struct dvb_frontend *fe, u8 *buf)
74{
75	struct cx23885_tsport *port = fe->dvb->priv;
76	struct cx23885_dev *dev = port->dev;
77	u8 i, temp, ret = 0;
78
79	temp = buf[0];
80	for (i = 0; i < buf[0]; i++)
81		temp += buf[i + 1];
82	temp = (~temp + 1);/* get check sum */
83	buf[1 + buf[0]] = temp;
84
85	f300_set_line(dev, F300_RESET, 1);
86	f300_set_line(dev, F300_CLK, 1);
87	udelay(30);
88	f300_set_line(dev, F300_DATA, 1);
89	msleep(1);
90
91	/* question: */
92	f300_set_line(dev, F300_RESET, 0);/* begin to send data */
93	msleep(1);
94
95	f300_send_byte(dev, 0xe0);/* the slave address is 0xe0, write */
96	msleep(1);
97
98	temp = buf[0];
99	temp += 2;
100	for (i = 0; i < temp; i++)
101		f300_send_byte(dev, buf[i]);
102
103	f300_set_line(dev, F300_RESET, 1);/* sent data over */
104	f300_set_line(dev, F300_DATA, 1);
105
106	/* answer: */
107	temp = 0;
108	for (i = 0; ((i < 8) & (temp == 0)); i++) {
109		msleep(1);
110		if (f300_get_line(dev, F300_BUSY) == 0)
111			temp = 1;
112	}
113
114	if (i > 7) {
115		pr_err("%s: timeout, the slave no response\n",
116								__func__);
117		ret = 1; /* timeout, the slave no response */
118	} else { /* the slave not busy, prepare for getting data */
119		f300_set_line(dev, F300_RESET, 0);/*ready...*/
120		msleep(1);
121		f300_send_byte(dev, 0xe1);/* 0xe1 is Read */
122		msleep(1);
123		temp = f300_get_byte(dev);/*get the data length */
124		if (temp > 14)
125			temp = 14;
126
127		for (i = 0; i < (temp + 1); i++)
128			f300_get_byte(dev);/* get data to empty buffer */
129
130		f300_set_line(dev, F300_RESET, 1);/* received data over */
131		f300_set_line(dev, F300_DATA, 1);
132	}
133
134	return ret;
135}
136
137int f300_set_voltage(struct dvb_frontend *fe, enum fe_sec_voltage voltage)
138{
139	u8 buf[16];
140
141	buf[0] = 0x05;
142	buf[1] = 0x38;/* write port */
143	buf[2] = 0x01;/* A port, lnb power */
144
145	switch (voltage) {
146	case SEC_VOLTAGE_13:
147		buf[3] = 0x01;/* power on */
148		buf[4] = 0x02;/* B port, H/V */
149		buf[5] = 0x00;/*13V v*/
150		break;
151	case SEC_VOLTAGE_18:
152		buf[3] = 0x01;
153		buf[4] = 0x02;
154		buf[5] = 0x01;/* 18V h*/
155		break;
156	case SEC_VOLTAGE_OFF:
157		buf[3] = 0x00;/* power off */
158		buf[4] = 0x00;
159		buf[5] = 0x00;
160		break;
161	}
162
163	return f300_xfer(fe, buf);
164}
165