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