diff options
Diffstat (limited to 'drivers/fsi/fsi-master-hub.c')
| -rw-r--r-- | drivers/fsi/fsi-master-hub.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c new file mode 100644 index 000000000000..133b9bff1d65 --- /dev/null +++ b/drivers/fsi/fsi-master-hub.c @@ -0,0 +1,327 @@ +/* + * FSI hub master driver + * + * Copyright (C) IBM Corporation 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/delay.h> +#include <linux/fsi.h> +#include <linux/module.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, 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 = ~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_info(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.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) + return 0; + + kfree(hub); +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); + 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"); |