1 /*
2 * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
3 *
4 * Copyright © 2006-2007 Red Hat, Inc.
5 * Copyright © 2006-2007 Advanced Micro Devices, Inc.
6 * Copyright © 2009 VIA Technology, Inc.
7 * Copyright (c) 2010 Andres Salomon <dilinger@queued.net>
8 *
9 * This program is free software. You can redistribute it and/or
10 * modify it under the terms of version 2 of the GNU General Public
11 * License as published by the Free Software Foundation.
12 */
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/cs5535.h>
17 #include <linux/gpio.h>
18 #include <linux/delay.h>
19 #include <asm/olpc.h>
20
21 #include "olpc_dcon.h"
22
dcon_init_xo_1(struct dcon_priv * dcon)23 static int dcon_init_xo_1(struct dcon_priv *dcon)
24 {
25 unsigned char lob;
26
27 if (gpio_request(OLPC_GPIO_DCON_STAT0, "OLPC-DCON")) {
28 pr_err("failed to request STAT0 GPIO\n");
29 return -EIO;
30 }
31 if (gpio_request(OLPC_GPIO_DCON_STAT1, "OLPC-DCON")) {
32 pr_err("failed to request STAT1 GPIO\n");
33 goto err_gp_stat1;
34 }
35 if (gpio_request(OLPC_GPIO_DCON_IRQ, "OLPC-DCON")) {
36 pr_err("failed to request IRQ GPIO\n");
37 goto err_gp_irq;
38 }
39 if (gpio_request(OLPC_GPIO_DCON_LOAD, "OLPC-DCON")) {
40 pr_err("failed to request LOAD GPIO\n");
41 goto err_gp_load;
42 }
43 if (gpio_request(OLPC_GPIO_DCON_BLANK, "OLPC-DCON")) {
44 pr_err("failed to request BLANK GPIO\n");
45 goto err_gp_blank;
46 }
47
48 /* Turn off the event enable for GPIO7 just to be safe */
49 cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
50
51 /*
52 * Determine the current state by reading the GPIO bit; earlier
53 * stages of the boot process have established the state.
54 *
55 * Note that we read GPIO_OUTPUT_VAL rather than GPIO_READ_BACK here;
56 * this is because OFW will disable input for the pin and set a value..
57 * READ_BACK will only contain a valid value if input is enabled and
58 * then a value is set. So, future readings of the pin can use
59 * READ_BACK, but the first one cannot. Awesome, huh?
60 */
61 dcon->curr_src = cs5535_gpio_isset(OLPC_GPIO_DCON_LOAD, GPIO_OUTPUT_VAL)
62 ? DCON_SOURCE_CPU
63 : DCON_SOURCE_DCON;
64 dcon->pending_src = dcon->curr_src;
65
66 /* Set the directions for the GPIO pins */
67 gpio_direction_input(OLPC_GPIO_DCON_STAT0);
68 gpio_direction_input(OLPC_GPIO_DCON_STAT1);
69 gpio_direction_input(OLPC_GPIO_DCON_IRQ);
70 gpio_direction_input(OLPC_GPIO_DCON_BLANK);
71 gpio_direction_output(OLPC_GPIO_DCON_LOAD,
72 dcon->curr_src == DCON_SOURCE_CPU);
73
74 /* Set up the interrupt mappings */
75
76 /* Set the IRQ to pair 2 */
77 cs5535_gpio_setup_event(OLPC_GPIO_DCON_IRQ, 2, 0);
78
79 /* Enable group 2 to trigger the DCON interrupt */
80 cs5535_gpio_set_irq(2, DCON_IRQ);
81
82 /* Select edge level for interrupt (in PIC) */
83 lob = inb(0x4d0);
84 lob &= ~(1 << DCON_IRQ);
85 outb(lob, 0x4d0);
86
87 /* Register the interrupt handler */
88 if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", dcon)) {
89 pr_err("failed to request DCON's irq\n");
90 goto err_req_irq;
91 }
92
93 /* Clear INV_EN for GPIO7 (DCONIRQ) */
94 cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_INVERT);
95
96 /* Enable filter for GPIO12 (DCONBLANK) */
97 cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_FILTER);
98
99 /* Disable filter for GPIO7 */
100 cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_FILTER);
101
102 /* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
103 cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_EVENT_COUNT);
104 cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_EVENT_COUNT);
105
106 /* Add GPIO12 to the Filter Event Pair #7 */
107 cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_FE7_SEL);
108
109 /* Turn off negative Edge Enable for GPIO12 */
110 cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_EN);
111
112 /* Enable negative Edge Enable for GPIO7 */
113 cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_EN);
114
115 /* Zero the filter amount for Filter Event Pair #7 */
116 cs5535_gpio_set(0, GPIO_FLTR7_AMOUNT);
117
118 /* Clear the negative edge status for GPIO7 and GPIO12 */
119 cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
120 cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_STS);
121
122 /* FIXME: Clear the positive status as well, just to be sure */
123 cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_POSITIVE_EDGE_STS);
124 cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_POSITIVE_EDGE_STS);
125
126 /* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
127 cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
128 cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_EVENTS_ENABLE);
129
130 return 0;
131
132 err_req_irq:
133 gpio_free(OLPC_GPIO_DCON_BLANK);
134 err_gp_blank:
135 gpio_free(OLPC_GPIO_DCON_LOAD);
136 err_gp_load:
137 gpio_free(OLPC_GPIO_DCON_IRQ);
138 err_gp_irq:
139 gpio_free(OLPC_GPIO_DCON_STAT1);
140 err_gp_stat1:
141 gpio_free(OLPC_GPIO_DCON_STAT0);
142 return -EIO;
143 }
144
dcon_wiggle_xo_1(void)145 static void dcon_wiggle_xo_1(void)
146 {
147 int x;
148
149 /*
150 * According to HiMax, when powering the DCON up we should hold
151 * SMB_DATA high for 8 SMB_CLK cycles. This will force the DCON
152 * state machine to reset to a (sane) initial state. Mitch Bradley
153 * did some testing and discovered that holding for 16 SMB_CLK cycles
154 * worked a lot more reliably, so that's what we do here.
155 *
156 * According to the cs5536 spec, to set GPIO14 to SMB_CLK we must
157 * simultaneously set AUX1 IN/OUT to GPIO14; ditto for SMB_DATA and
158 * GPIO15.
159 */
160 cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
161 cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_VAL);
162 cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_ENABLE);
163 cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_ENABLE);
164 cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
165 cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
166 cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX2);
167 cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX2);
168 cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
169 cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
170
171 for (x = 0; x < 16; x++) {
172 udelay(5);
173 cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
174 udelay(5);
175 cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
176 }
177 udelay(5);
178 cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
179 cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
180 cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
181 cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
182 }
183
dcon_set_dconload_1(int val)184 static void dcon_set_dconload_1(int val)
185 {
186 gpio_set_value(OLPC_GPIO_DCON_LOAD, val);
187 }
188
dcon_read_status_xo_1(u8 * status)189 static int dcon_read_status_xo_1(u8 *status)
190 {
191 *status = gpio_get_value(OLPC_GPIO_DCON_STAT0);
192 *status |= gpio_get_value(OLPC_GPIO_DCON_STAT1) << 1;
193
194 /* Clear the negative edge status for GPIO7 */
195 cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
196
197 return 0;
198 }
199
200 struct dcon_platform_data dcon_pdata_xo_1 = {
201 .init = dcon_init_xo_1,
202 .bus_stabilize_wiggle = dcon_wiggle_xo_1,
203 .set_dconload = dcon_set_dconload_1,
204 .read_status = dcon_read_status_xo_1,
205 };
206