1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Maxim MAX7360 Core Driver 4 * 5 * Copyright 2025 Bootlin 6 * 7 * Authors: 8 * Kamel Bouhara <kamel.bouhara@bootlin.com> 9 * Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> 10 */ 11 12 #include <linux/array_size.h> 13 #include <linux/bits.h> 14 #include <linux/delay.h> 15 #include <linux/device/devres.h> 16 #include <linux/dev_printk.h> 17 #include <linux/err.h> 18 #include <linux/i2c.h> 19 #include <linux/interrupt.h> 20 #include <linux/mfd/core.h> 21 #include <linux/mfd/max7360.h> 22 #include <linux/mod_devicetable.h> 23 #include <linux/module.h> 24 #include <linux/regmap.h> 25 #include <linux/types.h> 26 27 static const struct mfd_cell max7360_cells[] = { 28 { .name = "max7360-pinctrl" }, 29 { .name = "max7360-pwm" }, 30 { .name = "max7360-keypad" }, 31 { .name = "max7360-rotary" }, 32 { 33 .name = "max7360-gpo", 34 .of_compatible = "maxim,max7360-gpo", 35 }, 36 { 37 .name = "max7360-gpio", 38 .of_compatible = "maxim,max7360-gpio", 39 }, 40 }; 41 42 static const struct regmap_range max7360_volatile_ranges[] = { 43 regmap_reg_range(MAX7360_REG_KEYFIFO, MAX7360_REG_KEYFIFO), 44 regmap_reg_range(MAX7360_REG_I2C_TIMEOUT, MAX7360_REG_RTR_CNT), 45 }; 46 47 static const struct regmap_access_table max7360_volatile_table = { 48 .yes_ranges = max7360_volatile_ranges, 49 .n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges), 50 }; 51 52 static const struct regmap_config max7360_regmap_config = { 53 .reg_bits = 8, 54 .val_bits = 8, 55 .max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1), 56 .volatile_table = &max7360_volatile_table, 57 .cache_type = REGCACHE_MAPLE, 58 }; 59 60 static int max7360_mask_irqs(struct regmap *regmap) 61 { 62 struct device *dev = regmap_get_device(regmap); 63 unsigned int val; 64 int ret; 65 66 /* 67 * GPIO/PWM interrupts are not masked on reset: as the MAX7360 "INTI" 68 * interrupt line is shared between GPIOs and rotary encoder, this could 69 * result in repeated spurious interrupts on the rotary encoder driver 70 * if the GPIO driver is not loaded. Mask them now to avoid this 71 * situation. 72 */ 73 for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) { 74 ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i), 75 MAX7360_PORT_CFG_INTERRUPT_MASK, 76 MAX7360_PORT_CFG_INTERRUPT_MASK); 77 if (ret) 78 return dev_err_probe(dev, ret, 79 "Failed to write MAX7360 port configuration\n"); 80 } 81 82 /* Read GPIO in register, to ACK any pending IRQ. */ 83 ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val); 84 if (ret) 85 return dev_err_probe(dev, ret, "Failed to read GPIO values\n"); 86 87 return 0; 88 } 89 90 static int max7360_reset(struct regmap *regmap) 91 { 92 struct device *dev = regmap_get_device(regmap); 93 int ret; 94 95 ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, MAX7360_GPIO_CFG_GPIO_RST); 96 if (ret) { 97 dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret); 98 return ret; 99 } 100 101 ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG, MAX7360_REG_GPIO_LAST); 102 if (ret) { 103 dev_err(dev, "Failed to drop regmap cache: %x\n", ret); 104 return ret; 105 } 106 107 ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0); 108 if (ret) { 109 dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret); 110 return ret; 111 } 112 113 ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0); 114 if (ret) 115 dev_err(dev, "Failed to reset GPO port count: %x\n", ret); 116 117 return ret; 118 } 119 120 static int max7360_probe(struct i2c_client *client) 121 { 122 struct device *dev = &client->dev; 123 struct regmap *regmap; 124 int ret; 125 126 regmap = devm_regmap_init_i2c(client, &max7360_regmap_config); 127 if (IS_ERR(regmap)) 128 return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialise regmap\n"); 129 130 ret = max7360_reset(regmap); 131 if (ret) 132 return dev_err_probe(dev, ret, "Failed to reset device\n"); 133 134 /* Get the device out of shutdown mode. */ 135 ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG, 136 MAX7360_GPIO_CFG_GPIO_EN, 137 MAX7360_GPIO_CFG_GPIO_EN); 138 if (ret) 139 return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n"); 140 141 ret = max7360_mask_irqs(regmap); 142 if (ret) 143 return dev_err_probe(dev, ret, "Could not mask interrupts\n"); 144 145 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, 146 max7360_cells, ARRAY_SIZE(max7360_cells), 147 NULL, 0, NULL); 148 if (ret) 149 return dev_err_probe(dev, ret, "Failed to register child devices\n"); 150 151 return 0; 152 } 153 154 static const struct of_device_id max7360_dt_match[] = { 155 { .compatible = "maxim,max7360" }, 156 {} 157 }; 158 MODULE_DEVICE_TABLE(of, max7360_dt_match); 159 160 static struct i2c_driver max7360_driver = { 161 .driver = { 162 .name = "max7360", 163 .of_match_table = max7360_dt_match, 164 }, 165 .probe = max7360_probe, 166 }; 167 module_i2c_driver(max7360_driver); 168 169 MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver"); 170 MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); 171 MODULE_LICENSE("GPL"); 172