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 }; 31 32 struct pca954x_priv { 33 u32 addr; /* I2C mux address */ 34 u32 width; /* I2C mux width - number of busses */ 35 struct gpio_desc gpio_mux_reset; 36 }; 37 38 static const struct chip_desc chips[] = { 39 [PCA9544] = { 40 .enable = 0x4, 41 .muxtype = pca954x_ismux, 42 }, 43 [PCA9547] = { 44 .enable = 0x8, 45 .muxtype = pca954x_ismux, 46 }, 47 [PCA9548] = { 48 .enable = 0x8, 49 .muxtype = pca954x_isswi, 50 }, 51 }; 52 53 static int pca954x_deselect(struct udevice *mux, struct udevice *bus, 54 uint channel) 55 { 56 struct pca954x_priv *priv = dev_get_priv(mux); 57 uchar byte = 0; 58 59 return dm_i2c_write(mux, priv->addr, &byte, 1); 60 } 61 62 static int pca954x_select(struct udevice *mux, struct udevice *bus, 63 uint channel) 64 { 65 struct pca954x_priv *priv = dev_get_priv(mux); 66 const struct chip_desc *chip = &chips[dev_get_driver_data(mux)]; 67 uchar byte; 68 69 if (chip->muxtype == pca954x_ismux) 70 byte = channel | chip->enable; 71 else 72 byte = 1 << channel; 73 74 return dm_i2c_write(mux, priv->addr, &byte, 1); 75 } 76 77 static const struct i2c_mux_ops pca954x_ops = { 78 .select = pca954x_select, 79 .deselect = pca954x_deselect, 80 }; 81 82 static const struct udevice_id pca954x_ids[] = { 83 { .compatible = "nxp,pca9544", .data = PCA9544 }, 84 { .compatible = "nxp,pca9547", .data = PCA9547 }, 85 { .compatible = "nxp,pca9548", .data = PCA9548 }, 86 { } 87 }; 88 89 static int pca954x_ofdata_to_platdata(struct udevice *dev) 90 { 91 struct pca954x_priv *priv = dev_get_priv(dev); 92 93 priv->addr = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", 0); 94 if (!priv->addr) { 95 debug("MUX not found\n"); 96 return -ENODEV; 97 } 98 priv->width = dev_get_driver_data(dev); 99 100 if (!priv->width) { 101 debug("No I2C MUX width specified\n"); 102 return -EINVAL; 103 } 104 105 debug("Device %s at 0x%x with width %d\n", 106 dev->name, priv->addr, priv->width); 107 108 return 0; 109 } 110 111 static int pca954x_probe(struct udevice *dev) 112 { 113 if (IS_ENABLED(CONFIG_DM_GPIO)) { 114 struct pca954x_priv *priv = dev_get_priv(dev); 115 int err; 116 117 err = gpio_request_by_name(dev, "reset-gpios", 0, 118 &priv->gpio_mux_reset, GPIOD_IS_OUT); 119 120 /* it's optional so only bail if we get a real error */ 121 if (err && (err != -ENOENT)) 122 return err; 123 124 /* dm will take care of polarity */ 125 if (dm_gpio_is_valid(&priv->gpio_mux_reset)) 126 dm_gpio_set_value(&priv->gpio_mux_reset, 0); 127 } 128 129 return 0; 130 } 131 132 static int pca954x_remove(struct udevice *dev) 133 { 134 if (IS_ENABLED(CONFIG_DM_GPIO)) { 135 struct pca954x_priv *priv = dev_get_priv(dev); 136 137 if (dm_gpio_is_valid(&priv->gpio_mux_reset)) 138 dm_gpio_free(dev, &priv->gpio_mux_reset); 139 } 140 141 return 0; 142 } 143 144 U_BOOT_DRIVER(pca954x) = { 145 .name = "pca954x", 146 .id = UCLASS_I2C_MUX, 147 .of_match = pca954x_ids, 148 .probe = pca954x_probe, 149 .remove = pca954x_remove, 150 .ops = &pca954x_ops, 151 .ofdata_to_platdata = pca954x_ofdata_to_platdata, 152 .priv_auto_alloc_size = sizeof(struct pca954x_priv), 153 }; 154