| // 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" |
| |
| /* Control Registers */ |
| #define FSI_MMODE 0x0 /* R/W: mode */ |
| #define FSI_MDLYR 0x4 /* R/W: delay */ |
| #define FSI_MCRSP 0x8 /* R/W: clock rate */ |
| #define FSI_MENP0 0x10 /* R/W: enable */ |
| #define FSI_MLEVP0 0x18 /* R: plug detect */ |
| #define FSI_MSENP0 0x18 /* S: Set enable */ |
| #define FSI_MCENP0 0x20 /* C: Clear enable */ |
| #define FSI_MAEB 0x70 /* R: Error address */ |
| #define FSI_MVER 0x74 /* R: master version/type */ |
| #define FSI_MRESP0 0xd0 /* W: Port reset */ |
| #define FSI_MESRB0 0x1d0 /* R: Master error status */ |
| #define FSI_MRESB0 0x1d0 /* W: Reset bridge */ |
| #define FSI_MECTRL 0x2e0 /* W: Error control */ |
| |
| /* MMODE: Mode control */ |
| #define FSI_MMODE_EIP 0x80000000 /* Enable interrupt polling */ |
| #define FSI_MMODE_ECRC 0x40000000 /* Enable error recovery */ |
| #define FSI_MMODE_EPC 0x10000000 /* Enable parity checking */ |
| #define FSI_MMODE_P8_TO_LSB 0x00000010 /* Timeout value LSB */ |
| /* MSB=1, LSB=0 is 0.8 ms */ |
| /* MSB=0, LSB=1 is 0.9 ms */ |
| #define FSI_MMODE_CRS0SHFT 18 /* Clk rate selection 0 shift */ |
| #define FSI_MMODE_CRS0MASK 0x3ff /* Clk rate selection 0 mask */ |
| #define FSI_MMODE_CRS1SHFT 8 /* Clk rate selection 1 shift */ |
| #define FSI_MMODE_CRS1MASK 0x3ff /* Clk rate selection 1 mask */ |
| |
| /* MRESB: Reset brindge */ |
| #define FSI_MRESB_RST_GEN 0x80000000 /* General reset */ |
| #define FSI_MRESB_RST_ERR 0x40000000 /* Error Reset */ |
| |
| /* MRESB: Reset port */ |
| #define FSI_MRESP_RST_ALL_MASTER 0x20000000 /* Reset all FSI masters */ |
| #define FSI_MRESP_RST_ALL_LINK 0x10000000 /* Reset all FSI port contr. */ |
| #define FSI_MRESP_RST_MCR 0x08000000 /* Reset FSI master reg. */ |
| #define FSI_MRESP_RST_PYE 0x04000000 /* Reset FSI parity error */ |
| #define FSI_MRESP_RST_ALL 0xfc000000 /* Reset any error */ |
| |
| /* MECTRL: Error control */ |
| #define FSI_MECTRL_EOAE 0x8000 /* Enable machine check when */ |
| /* master 0 in error */ |
| #define FSI_MECTRL_P8_AUTO_TERM 0x4000 /* Auto terminate */ |
| |
| #define FSI_ENGID_HUB_MASTER 0x1c |
| #define FSI_HUB_LINK_OFFSET 0x80000 |
| #define FSI_HUB_LINK_SIZE 0x80000 |
| #define FSI_HUB_MASTER_MAX_LINKS 8 |
| |
| #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) |
| { |
| 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); |
| |
| rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), ®, 4); |
| |
| mdelay(FSI_LINK_ENABLE_SETUP_TIME); |
| |
| fsi_device_read(hub->upstream, FSI_MENP0 + (4 * idx), ®, 4); |
| |
| return rc; |
| } |
| |
| 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 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"); |