1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Copyright (C) 2023 Loongson Technology Corporation Limited |
4 | */ |
5 | |
6 | #include <drm/drm_managed.h> |
7 | |
8 | #include "lsdc_drv.h" |
9 | #include "lsdc_output.h" |
10 | |
11 | /* |
12 | * __lsdc_gpio_i2c_set - set the state of a gpio pin indicated by mask |
13 | * @mask: gpio pin mask |
14 | * @state: "0" for low, "1" for high |
15 | */ |
16 | static void __lsdc_gpio_i2c_set(struct lsdc_i2c * const li2c, int mask, int state) |
17 | { |
18 | struct lsdc_device *ldev = to_lsdc(ddev: li2c->ddev); |
19 | unsigned long flags; |
20 | u8 val; |
21 | |
22 | spin_lock_irqsave(&ldev->reglock, flags); |
23 | |
24 | if (state) { |
25 | /* |
26 | * Setting this pin as input directly, write 1 for input. |
27 | * The external pull-up resistor will pull the level up |
28 | */ |
29 | val = readb(addr: li2c->dir_reg); |
30 | val |= mask; |
31 | writeb(val, addr: li2c->dir_reg); |
32 | } else { |
33 | /* First set this pin as output, write 0 for output */ |
34 | val = readb(addr: li2c->dir_reg); |
35 | val &= ~mask; |
36 | writeb(val, addr: li2c->dir_reg); |
37 | |
38 | /* Then, make this pin output 0 */ |
39 | val = readb(addr: li2c->dat_reg); |
40 | val &= ~mask; |
41 | writeb(val, addr: li2c->dat_reg); |
42 | } |
43 | |
44 | spin_unlock_irqrestore(lock: &ldev->reglock, flags); |
45 | } |
46 | |
47 | /* |
48 | * __lsdc_gpio_i2c_get - read value back from the gpio pin indicated by mask |
49 | * @mask: gpio pin mask |
50 | * return "0" for low, "1" for high |
51 | */ |
52 | static int __lsdc_gpio_i2c_get(struct lsdc_i2c * const li2c, int mask) |
53 | { |
54 | struct lsdc_device *ldev = to_lsdc(ddev: li2c->ddev); |
55 | unsigned long flags; |
56 | u8 val; |
57 | |
58 | spin_lock_irqsave(&ldev->reglock, flags); |
59 | |
60 | /* First set this pin as input */ |
61 | val = readb(addr: li2c->dir_reg); |
62 | val |= mask; |
63 | writeb(val, addr: li2c->dir_reg); |
64 | |
65 | /* Then get level state from this pin */ |
66 | val = readb(addr: li2c->dat_reg); |
67 | |
68 | spin_unlock_irqrestore(lock: &ldev->reglock, flags); |
69 | |
70 | return (val & mask) ? 1 : 0; |
71 | } |
72 | |
73 | static void lsdc_gpio_i2c_set_sda(void *i2c, int state) |
74 | { |
75 | struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c; |
76 | /* set state on the li2c->sda pin */ |
77 | return __lsdc_gpio_i2c_set(li2c, mask: li2c->sda, state); |
78 | } |
79 | |
80 | static void lsdc_gpio_i2c_set_scl(void *i2c, int state) |
81 | { |
82 | struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c; |
83 | /* set state on the li2c->scl pin */ |
84 | return __lsdc_gpio_i2c_set(li2c, mask: li2c->scl, state); |
85 | } |
86 | |
87 | static int lsdc_gpio_i2c_get_sda(void *i2c) |
88 | { |
89 | struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c; |
90 | /* read value from the li2c->sda pin */ |
91 | return __lsdc_gpio_i2c_get(li2c, mask: li2c->sda); |
92 | } |
93 | |
94 | static int lsdc_gpio_i2c_get_scl(void *i2c) |
95 | { |
96 | struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c; |
97 | /* read the value from the li2c->scl pin */ |
98 | return __lsdc_gpio_i2c_get(li2c, mask: li2c->scl); |
99 | } |
100 | |
101 | static void lsdc_destroy_i2c(struct drm_device *ddev, void *data) |
102 | { |
103 | struct lsdc_i2c *li2c = (struct lsdc_i2c *)data; |
104 | |
105 | if (li2c) { |
106 | i2c_del_adapter(adap: &li2c->adapter); |
107 | kfree(objp: li2c); |
108 | } |
109 | } |
110 | |
111 | /* |
112 | * The DC in ls7a1000/ls7a2000/ls2k2000 has builtin gpio hardware |
113 | * |
114 | * @reg_base: gpio reg base |
115 | * @index: output channel index, 0 for PIPE0, 1 for PIPE1 |
116 | */ |
117 | int lsdc_create_i2c_chan(struct drm_device *ddev, |
118 | struct lsdc_display_pipe *dispipe, |
119 | unsigned int index) |
120 | { |
121 | struct lsdc_device *ldev = to_lsdc(ddev); |
122 | struct i2c_adapter *adapter; |
123 | struct lsdc_i2c *li2c; |
124 | int ret; |
125 | |
126 | li2c = kzalloc(size: sizeof(*li2c), GFP_KERNEL); |
127 | if (!li2c) |
128 | return -ENOMEM; |
129 | |
130 | dispipe->li2c = li2c; |
131 | |
132 | if (index == 0) { |
133 | li2c->sda = 0x01; /* pin 0 */ |
134 | li2c->scl = 0x02; /* pin 1 */ |
135 | } else if (index == 1) { |
136 | li2c->sda = 0x04; /* pin 2 */ |
137 | li2c->scl = 0x08; /* pin 3 */ |
138 | } else { |
139 | return -ENOENT; |
140 | } |
141 | |
142 | li2c->ddev = ddev; |
143 | li2c->dir_reg = ldev->reg_base + LS7A_DC_GPIO_DIR_REG; |
144 | li2c->dat_reg = ldev->reg_base + LS7A_DC_GPIO_DAT_REG; |
145 | |
146 | li2c->bit.setsda = lsdc_gpio_i2c_set_sda; |
147 | li2c->bit.setscl = lsdc_gpio_i2c_set_scl; |
148 | li2c->bit.getsda = lsdc_gpio_i2c_get_sda; |
149 | li2c->bit.getscl = lsdc_gpio_i2c_get_scl; |
150 | li2c->bit.udelay = 5; |
151 | li2c->bit.timeout = usecs_to_jiffies(u: 2200); |
152 | li2c->bit.data = li2c; |
153 | |
154 | adapter = &li2c->adapter; |
155 | adapter->algo_data = &li2c->bit; |
156 | adapter->owner = THIS_MODULE; |
157 | adapter->dev.parent = ddev->dev; |
158 | adapter->nr = -1; |
159 | |
160 | snprintf(buf: adapter->name, size: sizeof(adapter->name), fmt: "lsdc-i2c%u" , index); |
161 | |
162 | i2c_set_adapdata(adap: adapter, data: li2c); |
163 | |
164 | ret = i2c_bit_add_bus(adapter); |
165 | if (ret) { |
166 | kfree(objp: li2c); |
167 | return ret; |
168 | } |
169 | |
170 | ret = drmm_add_action_or_reset(ddev, lsdc_destroy_i2c, li2c); |
171 | if (ret) |
172 | return ret; |
173 | |
174 | drm_info(ddev, "%s(sda pin mask=%u, scl pin mask=%u) created\n" , |
175 | adapter->name, li2c->sda, li2c->scl); |
176 | |
177 | return 0; |
178 | } |
179 | |