127755cf7SEnric Balletbo i Serra // SPDX-License-Identifier: GPL-2.0+ 227755cf7SEnric Balletbo i Serra // Expose the vboot context nvram to userspace 327755cf7SEnric Balletbo i Serra // 427755cf7SEnric Balletbo i Serra // Copyright (C) 2012 Google, Inc. 527755cf7SEnric Balletbo i Serra // Copyright (C) 2015 Collabora Ltd. 618800fc7SEmilio López 718800fc7SEmilio López #include <linux/of.h> 818800fc7SEmilio López #include <linux/platform_device.h> 9*0cb7b263STzung-Bi Shih #include <linux/mod_devicetable.h> 10acb9900fSEnric Balletbo i Serra #include <linux/module.h> 11840d9f13SEnric Balletbo i Serra #include <linux/platform_data/cros_ec_commands.h> 12840d9f13SEnric Balletbo i Serra #include <linux/platform_data/cros_ec_proto.h> 1318800fc7SEmilio López #include <linux/slab.h> 1418800fc7SEmilio López 15acb9900fSEnric Balletbo i Serra #define DRV_NAME "cros-ec-vbc" 16acb9900fSEnric Balletbo i Serra 1718800fc7SEmilio López static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj, 1818800fc7SEmilio López struct bin_attribute *att, char *buf, 1918800fc7SEmilio López loff_t pos, size_t count) 2018800fc7SEmilio López { 219aa7bd45SWang Qing struct device *dev = kobj_to_dev(kobj); 2279a3d603SGwendal Grignou struct cros_ec_dev *ec = to_cros_ec_dev(dev); 2318800fc7SEmilio López struct cros_ec_device *ecdev = ec->ec_dev; 2418800fc7SEmilio López struct cros_ec_command *msg; 2559a9ccf1SGustavo A. R. Silva /* 2659a9ccf1SGustavo A. R. Silva * This should be a pointer to the same type as op field in 2759a9ccf1SGustavo A. R. Silva * struct ec_params_vbnvcontext. 2859a9ccf1SGustavo A. R. Silva */ 2959a9ccf1SGustavo A. R. Silva uint32_t *params_op; 3018800fc7SEmilio López int err; 3159a9ccf1SGustavo A. R. Silva const size_t para_sz = sizeof(*params_op); 3218800fc7SEmilio López const size_t resp_sz = sizeof(struct ec_response_vbnvcontext); 3318800fc7SEmilio López const size_t payload = max(para_sz, resp_sz); 3418800fc7SEmilio López 3518800fc7SEmilio López msg = kmalloc(sizeof(*msg) + payload, GFP_KERNEL); 3618800fc7SEmilio López if (!msg) 3718800fc7SEmilio López return -ENOMEM; 3818800fc7SEmilio López 3918800fc7SEmilio López /* NB: we only kmalloc()ated enough space for the op field */ 4059a9ccf1SGustavo A. R. Silva params_op = (uint32_t *)msg->data; 4159a9ccf1SGustavo A. R. Silva *params_op = EC_VBNV_CONTEXT_OP_READ; 4218800fc7SEmilio López 4318800fc7SEmilio López msg->version = EC_VER_VBNV_CONTEXT; 4418800fc7SEmilio López msg->command = EC_CMD_VBNV_CONTEXT; 4518800fc7SEmilio López msg->outsize = para_sz; 4618800fc7SEmilio López msg->insize = resp_sz; 4718800fc7SEmilio López 486bc15ad7SEnric Balletbo i Serra err = cros_ec_cmd_xfer_status(ecdev, msg); 4918800fc7SEmilio López if (err < 0) { 5018800fc7SEmilio López dev_err(dev, "Error sending read request: %d\n", err); 5118800fc7SEmilio López kfree(msg); 5218800fc7SEmilio López return err; 5318800fc7SEmilio López } 5418800fc7SEmilio López 5518800fc7SEmilio López memcpy(buf, msg->data, resp_sz); 5618800fc7SEmilio López 5718800fc7SEmilio López kfree(msg); 5818800fc7SEmilio López return resp_sz; 5918800fc7SEmilio López } 6018800fc7SEmilio López 6118800fc7SEmilio López static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj, 6218800fc7SEmilio López struct bin_attribute *attr, char *buf, 6318800fc7SEmilio López loff_t pos, size_t count) 6418800fc7SEmilio López { 659aa7bd45SWang Qing struct device *dev = kobj_to_dev(kobj); 6679a3d603SGwendal Grignou struct cros_ec_dev *ec = to_cros_ec_dev(dev); 6718800fc7SEmilio López struct cros_ec_device *ecdev = ec->ec_dev; 6818800fc7SEmilio López struct ec_params_vbnvcontext *params; 6918800fc7SEmilio López struct cros_ec_command *msg; 7018800fc7SEmilio López int err; 7118800fc7SEmilio López const size_t para_sz = sizeof(*params); 7218800fc7SEmilio López const size_t data_sz = sizeof(params->block); 7318800fc7SEmilio López 7418800fc7SEmilio López /* Only write full values */ 7518800fc7SEmilio López if (count != data_sz) 7618800fc7SEmilio López return -EINVAL; 7718800fc7SEmilio López 7818800fc7SEmilio López msg = kmalloc(sizeof(*msg) + para_sz, GFP_KERNEL); 7918800fc7SEmilio López if (!msg) 8018800fc7SEmilio López return -ENOMEM; 8118800fc7SEmilio López 8218800fc7SEmilio López params = (struct ec_params_vbnvcontext *)msg->data; 8318800fc7SEmilio López params->op = EC_VBNV_CONTEXT_OP_WRITE; 8418800fc7SEmilio López memcpy(params->block, buf, data_sz); 8518800fc7SEmilio López 8618800fc7SEmilio López msg->version = EC_VER_VBNV_CONTEXT; 8718800fc7SEmilio López msg->command = EC_CMD_VBNV_CONTEXT; 8818800fc7SEmilio López msg->outsize = para_sz; 8918800fc7SEmilio López msg->insize = 0; 9018800fc7SEmilio López 916bc15ad7SEnric Balletbo i Serra err = cros_ec_cmd_xfer_status(ecdev, msg); 9218800fc7SEmilio López if (err < 0) { 9318800fc7SEmilio López dev_err(dev, "Error sending write request: %d\n", err); 9418800fc7SEmilio López kfree(msg); 9518800fc7SEmilio López return err; 9618800fc7SEmilio López } 9718800fc7SEmilio López 9818800fc7SEmilio López kfree(msg); 9918800fc7SEmilio López return data_sz; 10018800fc7SEmilio López } 10118800fc7SEmilio López 10218800fc7SEmilio López static BIN_ATTR_RW(vboot_context, 16); 10318800fc7SEmilio López 10418800fc7SEmilio López static struct bin_attribute *cros_ec_vbc_bin_attrs[] = { 10518800fc7SEmilio López &bin_attr_vboot_context, 10618800fc7SEmilio López NULL 10718800fc7SEmilio López }; 10818800fc7SEmilio López 109d7c1fef7SRikard Falkeborn static const struct attribute_group cros_ec_vbc_attr_group = { 11018800fc7SEmilio López .name = "vbc", 11118800fc7SEmilio López .bin_attrs = cros_ec_vbc_bin_attrs, 11218800fc7SEmilio López }; 113acb9900fSEnric Balletbo i Serra 114acb9900fSEnric Balletbo i Serra static int cros_ec_vbc_probe(struct platform_device *pd) 115acb9900fSEnric Balletbo i Serra { 116acb9900fSEnric Balletbo i Serra struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent); 117acb9900fSEnric Balletbo i Serra struct device *dev = &pd->dev; 118acb9900fSEnric Balletbo i Serra int ret; 119acb9900fSEnric Balletbo i Serra 120acb9900fSEnric Balletbo i Serra ret = sysfs_create_group(&ec_dev->class_dev.kobj, 121acb9900fSEnric Balletbo i Serra &cros_ec_vbc_attr_group); 122acb9900fSEnric Balletbo i Serra if (ret < 0) 123acb9900fSEnric Balletbo i Serra dev_err(dev, "failed to create %s attributes. err=%d\n", 124acb9900fSEnric Balletbo i Serra cros_ec_vbc_attr_group.name, ret); 125acb9900fSEnric Balletbo i Serra 126acb9900fSEnric Balletbo i Serra return ret; 127acb9900fSEnric Balletbo i Serra } 128acb9900fSEnric Balletbo i Serra 12958b15196SUwe Kleine-König static void cros_ec_vbc_remove(struct platform_device *pd) 130acb9900fSEnric Balletbo i Serra { 131acb9900fSEnric Balletbo i Serra struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent); 132acb9900fSEnric Balletbo i Serra 133acb9900fSEnric Balletbo i Serra sysfs_remove_group(&ec_dev->class_dev.kobj, 134acb9900fSEnric Balletbo i Serra &cros_ec_vbc_attr_group); 135acb9900fSEnric Balletbo i Serra } 136acb9900fSEnric Balletbo i Serra 137*0cb7b263STzung-Bi Shih static const struct platform_device_id cros_ec_vbc_id[] = { 138*0cb7b263STzung-Bi Shih { DRV_NAME, 0 }, 139*0cb7b263STzung-Bi Shih {} 140*0cb7b263STzung-Bi Shih }; 141*0cb7b263STzung-Bi Shih MODULE_DEVICE_TABLE(platform, cros_ec_vbc_id); 142*0cb7b263STzung-Bi Shih 143acb9900fSEnric Balletbo i Serra static struct platform_driver cros_ec_vbc_driver = { 144acb9900fSEnric Balletbo i Serra .driver = { 145acb9900fSEnric Balletbo i Serra .name = DRV_NAME, 146acb9900fSEnric Balletbo i Serra }, 147acb9900fSEnric Balletbo i Serra .probe = cros_ec_vbc_probe, 14858b15196SUwe Kleine-König .remove_new = cros_ec_vbc_remove, 149*0cb7b263STzung-Bi Shih .id_table = cros_ec_vbc_id, 150acb9900fSEnric Balletbo i Serra }; 151acb9900fSEnric Balletbo i Serra 152acb9900fSEnric Balletbo i Serra module_platform_driver(cros_ec_vbc_driver); 153acb9900fSEnric Balletbo i Serra 154acb9900fSEnric Balletbo i Serra MODULE_LICENSE("GPL"); 155acb9900fSEnric Balletbo i Serra MODULE_DESCRIPTION("Expose the vboot context nvram to userspace"); 156