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      1 /*	$NetBSD: amdgpu_hw_gpio.c,v 1.3 2021/12/19 12:02:39 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright 2012-15 Advanced Micro Devices, Inc.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included in
     14  * all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
     20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     22  * OTHER DEALINGS IN THE SOFTWARE.
     23  *
     24  * Authors: AMD
     25  *
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: amdgpu_hw_gpio.c,v 1.3 2021/12/19 12:02:39 riastradh Exp $");
     30 
     31 #include "dm_services.h"
     32 #include "include/gpio_types.h"
     33 #include "hw_gpio.h"
     34 
     35 #include "reg_helper.h"
     36 #include "gpio_regs.h"
     37 
     38 #undef FN
     39 #define FN(reg_name, field_name) \
     40 	gpio->regs->field_name ## _shift, gpio->regs->field_name ## _mask
     41 
     42 #define CTX \
     43 	gpio->base.ctx
     44 #define REG(reg)\
     45 	(gpio->regs->reg)
     46 
     47 static void store_registers(
     48 	struct hw_gpio *gpio)
     49 {
     50 	REG_GET(MASK_reg, MASK, &gpio->store.mask);
     51 	REG_GET(A_reg, A, &gpio->store.a);
     52 	REG_GET(EN_reg, EN, &gpio->store.en);
     53 	/* TODO store GPIO_MUX_CONTROL if we ever use it */
     54 }
     55 
     56 static void restore_registers(
     57 	struct hw_gpio *gpio)
     58 {
     59 	REG_UPDATE(MASK_reg, MASK, gpio->store.mask);
     60 	REG_UPDATE(A_reg, A, gpio->store.a);
     61 	REG_UPDATE(EN_reg, EN, gpio->store.en);
     62 	/* TODO restore GPIO_MUX_CONTROL if we ever use it */
     63 }
     64 
     65 bool dal_hw_gpio_open(
     66 	struct hw_gpio_pin *ptr,
     67 	enum gpio_mode mode)
     68 {
     69 	struct hw_gpio *pin = FROM_HW_GPIO_PIN(ptr);
     70 
     71 	store_registers(pin);
     72 
     73 	ptr->opened = (dal_hw_gpio_config_mode(pin, mode) == GPIO_RESULT_OK);
     74 
     75 	return ptr->opened;
     76 }
     77 
     78 enum gpio_result dal_hw_gpio_get_value(
     79 	const struct hw_gpio_pin *ptr,
     80 	uint32_t *value)
     81 {
     82 	const struct hw_gpio *gpio = const_container_of(ptr, struct hw_gpio, base);
     83 
     84 	enum gpio_result result = GPIO_RESULT_OK;
     85 
     86 	switch (ptr->mode) {
     87 	case GPIO_MODE_INPUT:
     88 	case GPIO_MODE_OUTPUT:
     89 	case GPIO_MODE_HARDWARE:
     90 	case GPIO_MODE_FAST_OUTPUT:
     91 		REG_GET(Y_reg, Y, value);
     92 		break;
     93 	default:
     94 		result = GPIO_RESULT_NON_SPECIFIC_ERROR;
     95 	}
     96 
     97 	return result;
     98 }
     99 
    100 enum gpio_result dal_hw_gpio_set_value(
    101 	const struct hw_gpio_pin *ptr,
    102 	uint32_t value)
    103 {
    104 	const struct hw_gpio *gpio = const_container_of(ptr, struct hw_gpio, base);
    105 
    106 	/* This is the public interface
    107 	 * where the input comes from client, not shifted yet
    108 	 * (because client does not know the shifts). */
    109 
    110 	switch (ptr->mode) {
    111 	case GPIO_MODE_OUTPUT:
    112 		REG_UPDATE(A_reg, A, value);
    113 		return GPIO_RESULT_OK;
    114 	case GPIO_MODE_FAST_OUTPUT:
    115 		/* We use (EN) to faster switch (used in DDC GPIO).
    116 		 * So (A) is grounded, output is driven by (EN = 0)
    117 		 * to pull the line down (output == 0) and (EN=1)
    118 		 * then output is tri-state */
    119 		REG_UPDATE(EN_reg, EN, ~value);
    120 		return GPIO_RESULT_OK;
    121 	default:
    122 		return GPIO_RESULT_NON_SPECIFIC_ERROR;
    123 	}
    124 }
    125 
    126 enum gpio_result dal_hw_gpio_change_mode(
    127 	struct hw_gpio_pin *ptr,
    128 	enum gpio_mode mode)
    129 {
    130 	struct hw_gpio *pin = FROM_HW_GPIO_PIN(ptr);
    131 
    132 	return dal_hw_gpio_config_mode(pin, mode);
    133 }
    134 
    135 void dal_hw_gpio_close(
    136 	struct hw_gpio_pin *ptr)
    137 {
    138 	struct hw_gpio *pin = FROM_HW_GPIO_PIN(ptr);
    139 
    140 	restore_registers(pin);
    141 
    142 	ptr->mode = GPIO_MODE_UNKNOWN;
    143 	ptr->opened = false;
    144 }
    145 
    146 enum gpio_result dal_hw_gpio_config_mode(
    147 	struct hw_gpio *gpio,
    148 	enum gpio_mode mode)
    149 {
    150 	gpio->base.mode = mode;
    151 
    152 	switch (mode) {
    153 	case GPIO_MODE_INPUT:
    154 		/* turn off output enable, act as input pin;
    155 		 * program the pin as GPIO, mask out signal driven by HW */
    156 		REG_UPDATE(EN_reg, EN, 0);
    157 		REG_UPDATE(MASK_reg, MASK, 1);
    158 		return GPIO_RESULT_OK;
    159 	case GPIO_MODE_OUTPUT:
    160 		/* turn on output enable, act as output pin;
    161 		 * program the pin as GPIO, mask out signal driven by HW */
    162 		REG_UPDATE(A_reg, A, 0);
    163 		REG_UPDATE(MASK_reg, MASK, 1);
    164 		return GPIO_RESULT_OK;
    165 	case GPIO_MODE_FAST_OUTPUT:
    166 		/* grounding the A register then use the EN register bit
    167 		 * will have faster effect on the rise time */
    168 		REG_UPDATE(A_reg, A, 0);
    169 		REG_UPDATE(MASK_reg, MASK, 1);
    170 		return GPIO_RESULT_OK;
    171 	case GPIO_MODE_HARDWARE:
    172 		/* program the pin as tri-state, pin is driven by HW */
    173 		REG_UPDATE(MASK_reg, MASK, 0);
    174 		return GPIO_RESULT_OK;
    175 	case GPIO_MODE_INTERRUPT:
    176 		/* Interrupt mode supported only by HPD (IrqGpio) pins. */
    177 		REG_UPDATE(MASK_reg, MASK, 0);
    178 		return GPIO_RESULT_OK;
    179 	default:
    180 		return GPIO_RESULT_NON_SPECIFIC_ERROR;
    181 	}
    182 }
    183 
    184 void dal_hw_gpio_construct(
    185 	struct hw_gpio *pin,
    186 	enum gpio_id id,
    187 	uint32_t en,
    188 	struct dc_context *ctx)
    189 {
    190 	pin->base.ctx = ctx;
    191 	pin->base.id = id;
    192 	pin->base.en = en;
    193 	pin->base.mode = GPIO_MODE_UNKNOWN;
    194 	pin->base.opened = false;
    195 
    196 	pin->store.mask = 0;
    197 	pin->store.a = 0;
    198 	pin->store.en = 0;
    199 	pin->store.mux = 0;
    200 
    201 	pin->mux_supported = false;
    202 }
    203 
    204 void dal_hw_gpio_destruct(
    205 	struct hw_gpio *pin)
    206 {
    207 	ASSERT(!pin->base.opened);
    208 }
    209