1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2023 Loongson Technology Corporation Limited
6 #include <drm/drm_managed.h>
9 #include "lsdc_output.h"
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
16 static void __lsdc_gpio_i2c_set(struct lsdc_i2c * const li2c, int mask, int state)
18 struct lsdc_device *ldev = to_lsdc(li2c->ddev);
22 spin_lock_irqsave(&ldev->reglock, flags);
26 * Setting this pin as input directly, write 1 for input.
27 * The external pull-up resistor will pull the level up
29 val = readb(li2c->dir_reg);
31 writeb(val, li2c->dir_reg);
33 /* First set this pin as output, write 0 for output */
34 val = readb(li2c->dir_reg);
36 writeb(val, li2c->dir_reg);
38 /* Then, make this pin output 0 */
39 val = readb(li2c->dat_reg);
41 writeb(val, li2c->dat_reg);
44 spin_unlock_irqrestore(&ldev->reglock, flags);
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
52 static int __lsdc_gpio_i2c_get(struct lsdc_i2c * const li2c, int mask)
54 struct lsdc_device *ldev = to_lsdc(li2c->ddev);
58 spin_lock_irqsave(&ldev->reglock, flags);
60 /* First set this pin as input */
61 val = readb(li2c->dir_reg);
63 writeb(val, li2c->dir_reg);
65 /* Then get level state from this pin */
66 val = readb(li2c->dat_reg);
68 spin_unlock_irqrestore(&ldev->reglock, flags);
70 return (val & mask) ? 1 : 0;
73 static void lsdc_gpio_i2c_set_sda(void *i2c, int state)
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, li2c->sda, state);
80 static void lsdc_gpio_i2c_set_scl(void *i2c, int state)
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, li2c->scl, state);
87 static int lsdc_gpio_i2c_get_sda(void *i2c)
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, li2c->sda);
94 static int lsdc_gpio_i2c_get_scl(void *i2c)
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, li2c->scl);
101 static void lsdc_destroy_i2c(struct drm_device *ddev, void *data)
103 struct lsdc_i2c *li2c = (struct lsdc_i2c *)data;
106 i2c_del_adapter(&li2c->adapter);
112 * The DC in ls7a1000/ls7a2000/ls2k2000 has builtin gpio hardware
114 * @reg_base: gpio reg base
115 * @index: output channel index, 0 for PIPE0, 1 for PIPE1
117 int lsdc_create_i2c_chan(struct drm_device *ddev,
118 struct lsdc_display_pipe *dispipe,
121 struct lsdc_device *ldev = to_lsdc(ddev);
122 struct i2c_adapter *adapter;
123 struct lsdc_i2c *li2c;
126 li2c = kzalloc(sizeof(*li2c), GFP_KERNEL);
130 dispipe->li2c = li2c;
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 */
143 li2c->dir_reg = ldev->reg_base + LS7A_DC_GPIO_DIR_REG;
144 li2c->dat_reg = ldev->reg_base + LS7A_DC_GPIO_DAT_REG;
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(2200);
152 li2c->bit.data = li2c;
154 adapter = &li2c->adapter;
155 adapter->algo_data = &li2c->bit;
156 adapter->owner = THIS_MODULE;
157 adapter->class = I2C_CLASS_DDC;
158 adapter->dev.parent = ddev->dev;
161 snprintf(adapter->name, sizeof(adapter->name), "lsdc-i2c%u", index);
163 i2c_set_adapdata(adapter, li2c);
165 ret = i2c_bit_add_bus(adapter);
171 ret = drmm_add_action_or_reset(ddev, lsdc_destroy_i2c, li2c);
175 drm_info(ddev, "%s(sda pin mask=%u, scl pin mask=%u) created\n",
176 adapter->name, li2c->sda, li2c->scl);