1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2015 - 2016 Xilinx, Inc. 4 * Copyright (C) 2017 National Instruments Corp 5 * Written by Michal Simek 6 */ 7 8 #include <common.h> 9 #include <dm.h> 10 #include <errno.h> 11 #include <i2c.h> 12 13 #include <asm-generic/gpio.h> 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 enum pca_type { 18 PCA9544, 19 PCA9547, 20 PCA9548, 21 PCA9646 22 }; 23 24 struct chip_desc { 25 u8 enable; 26 enum muxtype { 27 pca954x_ismux = 0, 28 pca954x_isswi, 29 } muxtype; 30 u32 width; 31 }; 32 33 struct pca954x_priv { 34 u32 addr; /* I2C mux address */ 35 u32 width; /* I2C mux width - number of busses */ 36 struct gpio_desc gpio_mux_reset; 37 }; 38 39 static const struct chip_desc chips[] = { 40 [PCA9544] = { 41 .enable = 0x4, 42 .muxtype = pca954x_ismux, 43 .width = 4, 44 }, 45 [PCA9547] = { 46 .enable = 0x8, 47 .muxtype = pca954x_ismux, 48 .width = 8, 49 }, 50 [PCA9548] = { 51 .enable = 0x8, 52 .muxtype = pca954x_isswi, 53 .width = 8, 54 }, 55 [PCA9646] = { 56 .enable = 0x0, 57 .muxtype = pca954x_isswi, 58 .width = 4, 59 }, 60 }; 61 62 static int pca954x_deselect(struct udevice *mux, struct udevice *bus, 63 uint channel) 64 { 65 struct pca954x_priv *priv = dev_get_priv(mux); 66 uchar byte = 0; 67 68 return dm_i2c_write(mux, priv->addr, &byte, 1); 69 } 70 71 static int pca954x_select(struct udevice *mux, struct udevice *bus, 72 uint channel) 73 { 74 struct pca954x_priv *priv = dev_get_priv(mux); 75 const struct chip_desc *chip = &chips[dev_get_driver_data(mux)]; 76 uchar byte; 77 78 if (chip->muxtype == pca954x_ismux) 79 byte = channel | chip->enable; 80 else 81 byte = 1 << channel; 82 83 return dm_i2c_write(mux, priv->addr, &byte, 1); 84 } 85 86 static const struct i2c_mux_ops pca954x_ops = { 87 .select = pca954x_select, 88 .deselect = pca954x_deselect, 89 }; 90 91 static const struct udevice_id pca954x_ids[] = { 92 { .compatible = "nxp,pca9544", .data = PCA9544 }, 93 { .compatible = "nxp,pca9547", .data = PCA9547 }, 94 { .compatible = "nxp,pca9548", .data = PCA9548 }, 95 { .compatible = "nxp,pca9646", .data = PCA9646 }, 96 { } 97 }; 98 99 static int pca954x_ofdata_to_platdata(struct udevice *dev) 100 { 101 struct pca954x_priv *priv = dev_get_priv(dev); 102 const struct chip_desc *chip = &chips[dev_get_driver_data(dev)]; 103 104 priv->addr = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", 0); 105 if (!priv->addr) { 106 debug("MUX not found\n"); 107 return -ENODEV; 108 } 109 priv->width = chip->width; 110 111 if (!priv->width) { 112 debug("No I2C MUX width specified\n"); 113 return -EINVAL; 114 } 115 116 debug("Device %s at 0x%x with width %d\n", 117 dev->name, priv->addr, priv->width); 118 119 return 0; 120 } 121 122 static int pca954x_probe(struct udevice *dev) 123 { 124 if (IS_ENABLED(CONFIG_DM_GPIO)) { 125 struct pca954x_priv *priv = dev_get_priv(dev); 126 int err; 127 128 err = gpio_request_by_name(dev, "reset-gpios", 0, 129 &priv->gpio_mux_reset, GPIOD_IS_OUT); 130 131 /* it's optional so only bail if we get a real error */ 132 if (err && (err != -ENOENT)) 133 return err; 134 135 /* dm will take care of polarity */ 136 if (dm_gpio_is_valid(&priv->gpio_mux_reset)) 137 dm_gpio_set_value(&priv->gpio_mux_reset, 0); 138 } 139 140 return 0; 141 } 142 143 static int pca954x_remove(struct udevice *dev) 144 { 145 if (IS_ENABLED(CONFIG_DM_GPIO)) { 146 struct pca954x_priv *priv = dev_get_priv(dev); 147 148 if (dm_gpio_is_valid(&priv->gpio_mux_reset)) 149 dm_gpio_free(dev, &priv->gpio_mux_reset); 150 } 151 152 return 0; 153 } 154 155 U_BOOT_DRIVER(pca954x) = { 156 .name = "pca954x", 157 .id = UCLASS_I2C_MUX, 158 .of_match = pca954x_ids, 159 .probe = pca954x_probe, 160 .remove = pca954x_remove, 161 .ops = &pca954x_ops, 162 .ofdata_to_platdata = pca954x_ofdata_to_platdata, 163 .priv_auto_alloc_size = sizeof(struct pca954x_priv), 164 }; 165