1 /*
2  * Driver for Silicon Labs C8051F300 microcontroller.
3  *
4  * It is used for LNB power control in TeVii S470,
5  * TBS 6920 PCIe DVB-S2 cards.
6  *
7  * Microcontroller connected to cx23885 GPIO pins:
8  * GPIO0 - data		- P0.3 F300
9  * GPIO1 - reset	- P0.2 F300
10  * GPIO2 - clk		- P0.1 F300
11  * GPIO3 - busy		- P0.0 F300
12  *
13  * Copyright (C) 2009 Igor M. Liplianin <liplianin@me.by>
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  *
24  * GNU General Public License for more details.
25  */
26 
27 #include "cx23885.h"
28 #include "cx23885-f300.h"
29 
30 #define F300_DATA	GPIO_0
31 #define F300_RESET	GPIO_1
32 #define F300_CLK	GPIO_2
33 #define F300_BUSY	GPIO_3
34 
35 static void f300_set_line(struct cx23885_dev *dev, u32 line, u8 lvl)
36 {
37 	cx23885_gpio_enable(dev, line, 1);
38 	if (lvl == 1)
39 		cx23885_gpio_set(dev, line);
40 	else
41 		cx23885_gpio_clear(dev, line);
42 }
43 
44 static u8 f300_get_line(struct cx23885_dev *dev, u32 line)
45 {
46 	cx23885_gpio_enable(dev, line, 0);
47 
48 	return cx23885_gpio_get(dev, line);
49 }
50 
51 static void f300_send_byte(struct cx23885_dev *dev, u8 dta)
52 {
53 	u8 i;
54 
55 	for (i = 0; i < 8; i++) {
56 		f300_set_line(dev, F300_CLK, 0);
57 		udelay(30);
58 		f300_set_line(dev, F300_DATA, (dta & 0x80) >> 7);/* msb first */
59 		udelay(30);
60 		dta <<= 1;
61 		f300_set_line(dev, F300_CLK, 1);
62 		udelay(30);
63 	}
64 }
65 
66 static u8 f300_get_byte(struct cx23885_dev *dev)
67 {
68 	u8 i, dta = 0;
69 
70 	for (i = 0; i < 8; i++) {
71 		f300_set_line(dev, F300_CLK, 0);
72 		udelay(30);
73 		dta <<= 1;
74 		f300_set_line(dev, F300_CLK, 1);
75 		udelay(30);
76 		dta |= f300_get_line(dev, F300_DATA);/* msb first */
77 
78 	}
79 
80 	return dta;
81 }
82 
83 static u8 f300_xfer(struct dvb_frontend *fe, u8 *buf)
84 {
85 	struct cx23885_tsport *port = fe->dvb->priv;
86 	struct cx23885_dev *dev = port->dev;
87 	u8 i, temp, ret = 0;
88 
89 	temp = buf[0];
90 	for (i = 0; i < buf[0]; i++)
91 		temp += buf[i + 1];
92 	temp = (~temp + 1);/* get check sum */
93 	buf[1 + buf[0]] = temp;
94 
95 	f300_set_line(dev, F300_RESET, 1);
96 	f300_set_line(dev, F300_CLK, 1);
97 	udelay(30);
98 	f300_set_line(dev, F300_DATA, 1);
99 	msleep(1);
100 
101 	/* question: */
102 	f300_set_line(dev, F300_RESET, 0);/* begin to send data */
103 	msleep(1);
104 
105 	f300_send_byte(dev, 0xe0);/* the slave address is 0xe0, write */
106 	msleep(1);
107 
108 	temp = buf[0];
109 	temp += 2;
110 	for (i = 0; i < temp; i++)
111 		f300_send_byte(dev, buf[i]);
112 
113 	f300_set_line(dev, F300_RESET, 1);/* sent data over */
114 	f300_set_line(dev, F300_DATA, 1);
115 
116 	/* answer: */
117 	temp = 0;
118 	for (i = 0; ((i < 8) & (temp == 0)); i++) {
119 		msleep(1);
120 		if (f300_get_line(dev, F300_BUSY) == 0)
121 			temp = 1;
122 	}
123 
124 	if (i > 7) {
125 		pr_err("%s: timeout, the slave no response\n",
126 								__func__);
127 		ret = 1; /* timeout, the slave no response */
128 	} else { /* the slave not busy, prepare for getting data */
129 		f300_set_line(dev, F300_RESET, 0);/*ready...*/
130 		msleep(1);
131 		f300_send_byte(dev, 0xe1);/* 0xe1 is Read */
132 		msleep(1);
133 		temp = f300_get_byte(dev);/*get the data length */
134 		if (temp > 14)
135 			temp = 14;
136 
137 		for (i = 0; i < (temp + 1); i++)
138 			f300_get_byte(dev);/* get data to empty buffer */
139 
140 		f300_set_line(dev, F300_RESET, 1);/* received data over */
141 		f300_set_line(dev, F300_DATA, 1);
142 	}
143 
144 	return ret;
145 }
146 
147 int f300_set_voltage(struct dvb_frontend *fe, enum fe_sec_voltage voltage)
148 {
149 	u8 buf[16];
150 
151 	buf[0] = 0x05;
152 	buf[1] = 0x38;/* write port */
153 	buf[2] = 0x01;/* A port, lnb power */
154 
155 	switch (voltage) {
156 	case SEC_VOLTAGE_13:
157 		buf[3] = 0x01;/* power on */
158 		buf[4] = 0x02;/* B port, H/V */
159 		buf[5] = 0x00;/*13V v*/
160 		break;
161 	case SEC_VOLTAGE_18:
162 		buf[3] = 0x01;
163 		buf[4] = 0x02;
164 		buf[5] = 0x01;/* 18V h*/
165 		break;
166 	case SEC_VOLTAGE_OFF:
167 		buf[3] = 0x00;/* power off */
168 		buf[4] = 0x00;
169 		buf[5] = 0x00;
170 		break;
171 	}
172 
173 	return f300_xfer(fe, buf);
174 }
175