// SPDX-License-Identifier: GPL-2.0-only /* * FSI hub master driver * * Copyright (C) IBM Corporation 2016 */ #include <linux/delay.h> #include <linux/fsi.h> #include <linux/module.h> #include <linux/of.h> #include <linux/slab.h> #include "fsi-master.h" #define FSI_ENGID_HUB_MASTER 0x1c #define FSI_LINK_ENABLE_SETUP_TIME 10 /* in mS */ /* * FSI hub master support * * A hub master increases the number of potential target devices that the * primary FSI master can access. For each link a primary master supports, * each of those links can in turn be chained to a hub master with multiple * links of its own. * * The hub is controlled by a set of control registers exposed as a regular fsi * device (the hub->upstream device), and provides access to the downstream FSI * bus as through an address range on the slave itself (->addr and ->size). * * [This differs from "cascaded" masters, which expose the entire downstream * bus entirely through the fsi device address range, and so have a smaller * accessible address space.] */ struct fsi_master_hub { struct fsi_master master; struct fsi_device *upstream; uint32_t addr, size; /* slave-relative addr of */ /* master address space */ }; #define to_fsi_master_hub(m) container_of(m, struct fsi_master_hub, master) static int hub_master_read(struct fsi_master *master, int link, uint8_t id, uint32_t addr, void *val, size_t size) { struct fsi_master_hub *hub = to_fsi_master_hub(master); if (id != 0) return -EINVAL; addr += hub->addr + (link * FSI_HUB_LINK_SIZE); return fsi_slave_read(hub->upstream->slave, addr, val, size); } static int hub_master_write(struct fsi_master *master, int link, uint8_t id, uint32_t addr, const void *val, size_t size) { struct fsi_master_hub *hub = to_fsi_master_hub(master); if (id != 0) return -EINVAL; addr += hub->addr + (link * FSI_HUB_LINK_SIZE); return fsi_slave_write(hub->upstream->slave, addr, val, size); } static int hub_master_break(struct fsi_master *master, int link) { uint32_t addr; __be32 cmd; addr = 0x4; cmd = cpu_to_be32(0xc0de0000); return hub_master_write(master, link, 0, addr, &cmd, sizeof(cmd)); } static int hub_master_link_enable(struct fsi_master *master, int link, bool enable) { struct fsi_master_hub *hub = to_fsi_master_hub(master); int idx, bit; __be32 reg; int rc; idx = link / 32; bit = link % 32; reg = cpu_to_be32(0x80000000 >> bit); if (!enable) return fsi_device_write(hub->upstream, FSI_MCENP0 + (4 * idx), ®, 4); rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), ®, 4); if (rc) return rc; mdelay(FSI_LINK_ENABLE_SETUP_TIME); return 0; } static void hub_master_release(struct device *dev) { struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev)); kfree(hub); } /* mmode encoders */ static inline u32 fsi_mmode_crs0(u32 x) { return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT; } static inline u32 fsi_mmode_crs1(u32 x) { return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT; } static int hub_master_init(struct fsi_master_hub *hub) { struct fsi_device *dev = hub->upstream; __be32 reg; int rc; reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK | FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE); rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); if (rc) return rc; /* Initialize the MFSI (hub master) engine */ reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK | FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE); rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM); rc = fsi_device_write(dev, FSI_MECTRL, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(FSI_MMODE_EIP | FSI_MMODE_ECRC | FSI_MMODE_EPC | fsi_mmode_crs0(1) | fsi_mmode_crs1(1) | FSI_MMODE_P8_TO_LSB); rc = fsi_device_write(dev, FSI_MMODE, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(0xffff0000); rc = fsi_device_write(dev, FSI_MDLYR, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(~0); rc = fsi_device_write(dev, FSI_MSENP0, ®, sizeof(reg)); if (rc) return rc; /* Leave enabled long enough for master logic to set up */ mdelay(FSI_LINK_ENABLE_SETUP_TIME); rc = fsi_device_write(dev, FSI_MCENP0, ®, sizeof(reg)); if (rc) return rc; rc = fsi_device_read(dev, FSI_MAEB, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK); rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); if (rc) return rc; rc = fsi_device_read(dev, FSI_MLEVP0, ®, sizeof(reg)); if (rc) return rc; /* Reset the master bridge */ reg = cpu_to_be32(FSI_MRESB_RST_GEN); rc = fsi_device_write(dev, FSI_MRESB0, ®, sizeof(reg)); if (rc) return rc; reg = cpu_to_be32(FSI_MRESB_RST_ERR); return fsi_device_write(dev, FSI_MRESB0, ®, sizeof(reg)); } static int hub_master_probe(struct device *dev) { struct fsi_device *fsi_dev = to_fsi_dev(dev); struct fsi_master_hub *hub; uint32_t reg, links; __be32 __reg; int rc; rc = fsi_device_read(fsi_dev, FSI_MVER, &__reg, sizeof(__reg)); if (rc) return rc; reg = be32_to_cpu(__reg); links = (reg >> 8) & 0xff; dev_dbg(dev, "hub version %08x (%d links)\n", reg, links); rc = fsi_slave_claim_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET, FSI_HUB_LINK_SIZE * links); if (rc) { dev_err(dev, "can't claim slave address range for links"); return rc; } hub = kzalloc(sizeof(*hub), GFP_KERNEL); if (!hub) { rc = -ENOMEM; goto err_release; } hub->addr = FSI_HUB_LINK_OFFSET; hub->size = FSI_HUB_LINK_SIZE * links; hub->upstream = fsi_dev; hub->master.dev.parent = dev; hub->master.dev.release = hub_master_release; hub->master.dev.of_node = of_node_get(dev_of_node(dev)); hub->master.n_links = links; hub->master.read = hub_master_read; hub->master.write = hub_master_write; hub->master.send_break = hub_master_break; hub->master.link_enable = hub_master_link_enable; dev_set_drvdata(dev, hub); hub_master_init(hub); rc = fsi_master_register(&hub->master); if (rc) goto err_release; /* At this point, fsi_master_register performs the device_initialize(), * and holds the sole reference on master.dev. This means the device * will be freed (via ->release) during any subsequent call to * fsi_master_unregister. We add our own reference to it here, so we * can perform cleanup (in _remove()) without it being freed before * we're ready. */ get_device(&hub->master.dev); return 0; err_release: fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET, FSI_HUB_LINK_SIZE * links); return rc; } static int hub_master_remove(struct device *dev) { struct fsi_master_hub *hub = dev_get_drvdata(dev); fsi_master_unregister(&hub->master); fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size); of_node_put(hub->master.dev.of_node); /* * master.dev will likely be ->release()ed after this, which free()s * the hub */ put_device(&hub->master.dev); return 0; } static const struct fsi_device_id hub_master_ids[] = { { .engine_type = FSI_ENGID_HUB_MASTER, .version = FSI_VERSION_ANY, }, { 0 } }; static struct fsi_driver hub_master_driver = { .id_table = hub_master_ids, .drv = { .name = "fsi-master-hub", .bus = &fsi_bus_type, .probe = hub_master_probe, .remove = hub_master_remove, } }; module_fsi_driver(hub_master_driver); MODULE_LICENSE("GPL");