diff options
Diffstat (limited to 'drivers/fsi/fsi-master-aspeed.c')
| -rw-r--r-- | drivers/fsi/fsi-master-aspeed.c | 675 |
1 files changed, 675 insertions, 0 deletions
diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c new file mode 100644 index 000000000..5eccab175 --- /dev/null +++ b/drivers/fsi/fsi-master-aspeed.c @@ -0,0 +1,675 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// Copyright (C) IBM Corporation 2018 +// FSI master driver for AST2600 + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/fsi.h> +#include <linux/io.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/iopoll.h> +#include <linux/gpio/consumer.h> + +#include "fsi-master.h" + +struct fsi_master_aspeed { + struct fsi_master master; + struct mutex lock; /* protect HW access */ + struct device *dev; + void __iomem *base; + struct clk *clk; + struct gpio_desc *cfam_reset_gpio; +}; + +#define to_fsi_master_aspeed(m) \ + container_of(m, struct fsi_master_aspeed, master) + +/* Control register (size 0x400) */ +static const u32 ctrl_base = 0x80000000; + +static const u32 fsi_base = 0xa0000000; + +#define OPB_FSI_VER 0x00 +#define OPB_TRIGGER 0x04 +#define OPB_CTRL_BASE 0x08 +#define OPB_FSI_BASE 0x0c +#define OPB_CLK_SYNC 0x3c +#define OPB_IRQ_CLEAR 0x40 +#define OPB_IRQ_MASK 0x44 +#define OPB_IRQ_STATUS 0x48 + +#define OPB0_SELECT 0x10 +#define OPB0_RW 0x14 +#define OPB0_XFER_SIZE 0x18 +#define OPB0_FSI_ADDR 0x1c +#define OPB0_FSI_DATA_W 0x20 +#define OPB0_STATUS 0x80 +#define OPB0_FSI_DATA_R 0x84 + +#define OPB0_WRITE_ORDER1 0x4c +#define OPB0_WRITE_ORDER2 0x50 +#define OPB1_WRITE_ORDER1 0x54 +#define OPB1_WRITE_ORDER2 0x58 +#define OPB0_READ_ORDER1 0x5c +#define OPB1_READ_ORDER2 0x60 + +#define OPB_RETRY_COUNTER 0x64 + +/* OPBn_STATUS */ +#define STATUS_HALFWORD_ACK BIT(0) +#define STATUS_FULLWORD_ACK BIT(1) +#define STATUS_ERR_ACK BIT(2) +#define STATUS_RETRY BIT(3) +#define STATUS_TIMEOUT BIT(4) + +/* OPB_IRQ_MASK */ +#define OPB1_XFER_ACK_EN BIT(17) +#define OPB0_XFER_ACK_EN BIT(16) + +/* OPB_RW */ +#define CMD_READ BIT(0) +#define CMD_WRITE 0 + +/* OPBx_XFER_SIZE */ +#define XFER_FULLWORD (BIT(1) | BIT(0)) +#define XFER_HALFWORD (BIT(0)) +#define XFER_BYTE (0) + +#define CREATE_TRACE_POINTS +#include <trace/events/fsi_master_aspeed.h> + +#define FSI_LINK_ENABLE_SETUP_TIME 10 /* in mS */ + +/* Run the bus at maximum speed by default */ +#define FSI_DIVISOR_DEFAULT 1 +#define FSI_DIVISOR_CABLED 2 +static u16 aspeed_fsi_divisor = FSI_DIVISOR_DEFAULT; +module_param_named(bus_div,aspeed_fsi_divisor, ushort, 0); + +#define OPB_POLL_TIMEOUT 500 + +static int __opb_write(struct fsi_master_aspeed *aspeed, u32 addr, + u32 val, u32 transfer_size) +{ + void __iomem *base = aspeed->base; + u32 reg, status; + int ret; + + /* + * The ordering of these writes up until the trigger + * write does not matter, so use writel_relaxed. + */ + writel_relaxed(CMD_WRITE, base + OPB0_RW); + writel_relaxed(transfer_size, base + OPB0_XFER_SIZE); + writel_relaxed(addr, base + OPB0_FSI_ADDR); + writel_relaxed(val, base + OPB0_FSI_DATA_W); + writel_relaxed(0x1, base + OPB_IRQ_CLEAR); + writel(0x1, base + OPB_TRIGGER); + + ret = readl_poll_timeout(base + OPB_IRQ_STATUS, reg, + (reg & OPB0_XFER_ACK_EN) != 0, + 0, OPB_POLL_TIMEOUT); + + status = readl(base + OPB0_STATUS); + + trace_fsi_master_aspeed_opb_write(addr, val, transfer_size, status, reg); + + /* Return error when poll timed out */ + if (ret) + return ret; + + /* Command failed, master will reset */ + if (status & STATUS_ERR_ACK) + return -EIO; + + return 0; +} + +static int opb_writeb(struct fsi_master_aspeed *aspeed, u32 addr, u8 val) +{ + return __opb_write(aspeed, addr, val, XFER_BYTE); +} + +static int opb_writew(struct fsi_master_aspeed *aspeed, u32 addr, __be16 val) +{ + return __opb_write(aspeed, addr, (__force u16)val, XFER_HALFWORD); +} + +static int opb_writel(struct fsi_master_aspeed *aspeed, u32 addr, __be32 val) +{ + return __opb_write(aspeed, addr, (__force u32)val, XFER_FULLWORD); +} + +static int __opb_read(struct fsi_master_aspeed *aspeed, uint32_t addr, + u32 transfer_size, void *out) +{ + void __iomem *base = aspeed->base; + u32 result, reg; + int status, ret; + + /* + * The ordering of these writes up until the trigger + * write does not matter, so use writel_relaxed. + */ + writel_relaxed(CMD_READ, base + OPB0_RW); + writel_relaxed(transfer_size, base + OPB0_XFER_SIZE); + writel_relaxed(addr, base + OPB0_FSI_ADDR); + writel_relaxed(0x1, base + OPB_IRQ_CLEAR); + writel(0x1, base + OPB_TRIGGER); + + ret = readl_poll_timeout(base + OPB_IRQ_STATUS, reg, + (reg & OPB0_XFER_ACK_EN) != 0, + 0, OPB_POLL_TIMEOUT); + + status = readl(base + OPB0_STATUS); + + result = readl(base + OPB0_FSI_DATA_R); + + trace_fsi_master_aspeed_opb_read(addr, transfer_size, result, + readl(base + OPB0_STATUS), + reg); + + /* Return error when poll timed out */ + if (ret) + return ret; + + /* Command failed, master will reset */ + if (status & STATUS_ERR_ACK) + return -EIO; + + if (out) { + switch (transfer_size) { + case XFER_BYTE: + *(u8 *)out = result; + break; + case XFER_HALFWORD: + *(u16 *)out = result; + break; + case XFER_FULLWORD: + *(u32 *)out = result; + break; + default: + return -EINVAL; + } + + } + + return 0; +} + +static int opb_readl(struct fsi_master_aspeed *aspeed, uint32_t addr, __be32 *out) +{ + return __opb_read(aspeed, addr, XFER_FULLWORD, out); +} + +static int opb_readw(struct fsi_master_aspeed *aspeed, uint32_t addr, __be16 *out) +{ + return __opb_read(aspeed, addr, XFER_HALFWORD, (void *)out); +} + +static int opb_readb(struct fsi_master_aspeed *aspeed, uint32_t addr, u8 *out) +{ + return __opb_read(aspeed, addr, XFER_BYTE, (void *)out); +} + +static int check_errors(struct fsi_master_aspeed *aspeed, int err) +{ + int ret; + + if (trace_fsi_master_aspeed_opb_error_enabled()) { + __be32 mresp0, mstap0, mesrb0; + + opb_readl(aspeed, ctrl_base + FSI_MRESP0, &mresp0); + opb_readl(aspeed, ctrl_base + FSI_MSTAP0, &mstap0); + opb_readl(aspeed, ctrl_base + FSI_MESRB0, &mesrb0); + + trace_fsi_master_aspeed_opb_error( + be32_to_cpu(mresp0), + be32_to_cpu(mstap0), + be32_to_cpu(mesrb0)); + } + + if (err == -EIO) { + /* Check MAEB (0x70) ? */ + + /* Then clear errors in master */ + ret = opb_writel(aspeed, ctrl_base + FSI_MRESP0, + cpu_to_be32(FSI_MRESP_RST_ALL_MASTER)); + if (ret) { + /* TODO: log? return different code? */ + return ret; + } + /* TODO: confirm that 0x70 was okay */ + } + + /* This will pass through timeout errors */ + return err; +} + +static int aspeed_master_read(struct fsi_master *master, int link, + uint8_t id, uint32_t addr, void *val, size_t size) +{ + struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master); + int ret; + + if (id > 0x3) + return -EINVAL; + + addr |= id << 21; + addr += link * FSI_HUB_LINK_SIZE; + + mutex_lock(&aspeed->lock); + + switch (size) { + case 1: + ret = opb_readb(aspeed, fsi_base + addr, val); + break; + case 2: + ret = opb_readw(aspeed, fsi_base + addr, val); + break; + case 4: + ret = opb_readl(aspeed, fsi_base + addr, val); + break; + default: + ret = -EINVAL; + goto done; + } + + ret = check_errors(aspeed, ret); +done: + mutex_unlock(&aspeed->lock); + return ret; +} + +static int aspeed_master_write(struct fsi_master *master, int link, + uint8_t id, uint32_t addr, const void *val, size_t size) +{ + struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master); + int ret; + + if (id > 0x3) + return -EINVAL; + + addr |= id << 21; + addr += link * FSI_HUB_LINK_SIZE; + + mutex_lock(&aspeed->lock); + + switch (size) { + case 1: + ret = opb_writeb(aspeed, fsi_base + addr, *(u8 *)val); + break; + case 2: + ret = opb_writew(aspeed, fsi_base + addr, *(__be16 *)val); + break; + case 4: + ret = opb_writel(aspeed, fsi_base + addr, *(__be32 *)val); + break; + default: + ret = -EINVAL; + goto done; + } + + ret = check_errors(aspeed, ret); +done: + mutex_unlock(&aspeed->lock); + return ret; +} + +static int aspeed_master_link_enable(struct fsi_master *master, int link, + bool enable) +{ + struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master); + int idx, bit, ret; + __be32 reg; + + idx = link / 32; + bit = link % 32; + + reg = cpu_to_be32(0x80000000 >> bit); + + mutex_lock(&aspeed->lock); + + if (!enable) { + ret = opb_writel(aspeed, ctrl_base + FSI_MCENP0 + (4 * idx), reg); + goto done; + } + + ret = opb_writel(aspeed, ctrl_base + FSI_MSENP0 + (4 * idx), reg); + if (ret) + goto done; + + mdelay(FSI_LINK_ENABLE_SETUP_TIME); +done: + mutex_unlock(&aspeed->lock); + return ret; +} + +static int aspeed_master_term(struct fsi_master *master, int link, uint8_t id) +{ + uint32_t addr; + __be32 cmd; + + addr = 0x4; + cmd = cpu_to_be32(0xecc00000); + + return aspeed_master_write(master, link, id, addr, &cmd, 4); +} + +static int aspeed_master_break(struct fsi_master *master, int link) +{ + uint32_t addr; + __be32 cmd; + + addr = 0x0; + cmd = cpu_to_be32(0xc0de0000); + + return aspeed_master_write(master, link, 0, addr, &cmd, 4); +} + +static void aspeed_master_release(struct device *dev) +{ + struct fsi_master_aspeed *aspeed = + to_fsi_master_aspeed(dev_to_fsi_master(dev)); + + kfree(aspeed); +} + +/* 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 aspeed_master_init(struct fsi_master_aspeed *aspeed) +{ + __be32 reg; + + reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK + | FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE); + opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg); + + /* 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); + opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg); + + reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM); + opb_writel(aspeed, ctrl_base + FSI_MECTRL, reg); + + reg = cpu_to_be32(FSI_MMODE_ECRC | FSI_MMODE_EPC | FSI_MMODE_RELA + | fsi_mmode_crs0(aspeed_fsi_divisor) + | fsi_mmode_crs1(aspeed_fsi_divisor) + | FSI_MMODE_P8_TO_LSB); + dev_info(aspeed->dev, "mmode set to %08x (divisor %d)\n", + be32_to_cpu(reg), aspeed_fsi_divisor); + opb_writel(aspeed, ctrl_base + FSI_MMODE, reg); + + reg = cpu_to_be32(0xffff0000); + opb_writel(aspeed, ctrl_base + FSI_MDLYR, reg); + + reg = cpu_to_be32(~0); + opb_writel(aspeed, ctrl_base + FSI_MSENP0, reg); + + /* Leave enabled long enough for master logic to set up */ + mdelay(FSI_LINK_ENABLE_SETUP_TIME); + + opb_writel(aspeed, ctrl_base + FSI_MCENP0, reg); + + opb_readl(aspeed, ctrl_base + FSI_MAEB, NULL); + + reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK); + opb_writel(aspeed, ctrl_base + FSI_MRESP0, reg); + + opb_readl(aspeed, ctrl_base + FSI_MLEVP0, NULL); + + /* Reset the master bridge */ + reg = cpu_to_be32(FSI_MRESB_RST_GEN); + opb_writel(aspeed, ctrl_base + FSI_MRESB0, reg); + + reg = cpu_to_be32(FSI_MRESB_RST_ERR); + opb_writel(aspeed, ctrl_base + FSI_MRESB0, reg); + + return 0; +} + +static ssize_t cfam_reset_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fsi_master_aspeed *aspeed = dev_get_drvdata(dev); + + trace_fsi_master_aspeed_cfam_reset(true); + mutex_lock(&aspeed->lock); + gpiod_set_value(aspeed->cfam_reset_gpio, 1); + usleep_range(900, 1000); + gpiod_set_value(aspeed->cfam_reset_gpio, 0); + usleep_range(900, 1000); + opb_writel(aspeed, ctrl_base + FSI_MRESP0, cpu_to_be32(FSI_MRESP_RST_ALL_MASTER)); + mutex_unlock(&aspeed->lock); + trace_fsi_master_aspeed_cfam_reset(false); + + return count; +} + +static DEVICE_ATTR(cfam_reset, 0200, NULL, cfam_reset_store); + +static int setup_cfam_reset(struct fsi_master_aspeed *aspeed) +{ + struct device *dev = aspeed->dev; + struct gpio_desc *gpio; + int rc; + + gpio = devm_gpiod_get_optional(dev, "cfam-reset", GPIOD_OUT_LOW); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + if (!gpio) + return 0; + + aspeed->cfam_reset_gpio = gpio; + + rc = device_create_file(dev, &dev_attr_cfam_reset); + if (rc) { + devm_gpiod_put(dev, gpio); + return rc; + } + + return 0; +} + +static int tacoma_cabled_fsi_fixup(struct device *dev) +{ + struct gpio_desc *routing_gpio, *mux_gpio; + int gpio; + + /* + * The routing GPIO is a jumper indicating we should mux for the + * externally connected FSI cable. + */ + routing_gpio = devm_gpiod_get_optional(dev, "fsi-routing", + GPIOD_IN | GPIOD_FLAGS_BIT_NONEXCLUSIVE); + if (IS_ERR(routing_gpio)) + return PTR_ERR(routing_gpio); + if (!routing_gpio) + return 0; + + mux_gpio = devm_gpiod_get_optional(dev, "fsi-mux", GPIOD_ASIS); + if (IS_ERR(mux_gpio)) + return PTR_ERR(mux_gpio); + if (!mux_gpio) + return 0; + + gpio = gpiod_get_value(routing_gpio); + if (gpio < 0) + return gpio; + + /* If the routing GPIO is high we should set the mux to low. */ + if (gpio) { + /* + * Cable signal integrity means we should run the bus + * slightly slower. Do not override if a kernel param + * has already overridden. + */ + if (aspeed_fsi_divisor == FSI_DIVISOR_DEFAULT) + aspeed_fsi_divisor = FSI_DIVISOR_CABLED; + + gpiod_direction_output(mux_gpio, 0); + dev_info(dev, "FSI configured for external cable\n"); + } else { + gpiod_direction_output(mux_gpio, 1); + } + + devm_gpiod_put(dev, routing_gpio); + + return 0; +} + +static int fsi_master_aspeed_probe(struct platform_device *pdev) +{ + struct fsi_master_aspeed *aspeed; + int rc, links, reg; + __be32 raw; + + rc = tacoma_cabled_fsi_fixup(&pdev->dev); + if (rc) { + dev_err(&pdev->dev, "Tacoma FSI cable fixup failed\n"); + return rc; + } + + aspeed = kzalloc(sizeof(*aspeed), GFP_KERNEL); + if (!aspeed) + return -ENOMEM; + + aspeed->dev = &pdev->dev; + + aspeed->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(aspeed->base)) { + rc = PTR_ERR(aspeed->base); + goto err_free_aspeed; + } + + aspeed->clk = devm_clk_get(aspeed->dev, NULL); + if (IS_ERR(aspeed->clk)) { + dev_err(aspeed->dev, "couldn't get clock\n"); + rc = PTR_ERR(aspeed->clk); + goto err_free_aspeed; + } + rc = clk_prepare_enable(aspeed->clk); + if (rc) { + dev_err(aspeed->dev, "couldn't enable clock\n"); + goto err_free_aspeed; + } + + rc = setup_cfam_reset(aspeed); + if (rc) { + dev_err(&pdev->dev, "CFAM reset GPIO setup failed\n"); + } + + writel(0x1, aspeed->base + OPB_CLK_SYNC); + writel(OPB1_XFER_ACK_EN | OPB0_XFER_ACK_EN, + aspeed->base + OPB_IRQ_MASK); + + /* TODO: determine an appropriate value */ + writel(0x10, aspeed->base + OPB_RETRY_COUNTER); + + writel(ctrl_base, aspeed->base + OPB_CTRL_BASE); + writel(fsi_base, aspeed->base + OPB_FSI_BASE); + + /* Set read data order */ + writel(0x00030b1b, aspeed->base + OPB0_READ_ORDER1); + + /* Set write data order */ + writel(0x0011101b, aspeed->base + OPB0_WRITE_ORDER1); + writel(0x0c330f3f, aspeed->base + OPB0_WRITE_ORDER2); + + /* + * Select OPB0 for all operations. + * Will need to be reworked when enabling DMA or anything that uses + * OPB1. + */ + writel(0x1, aspeed->base + OPB0_SELECT); + + rc = opb_readl(aspeed, ctrl_base + FSI_MVER, &raw); + if (rc) { + dev_err(&pdev->dev, "failed to read hub version\n"); + goto err_release; + } + + reg = be32_to_cpu(raw); + links = (reg >> 8) & 0xff; + dev_info(&pdev->dev, "hub version %08x (%d links)\n", reg, links); + + aspeed->master.dev.parent = &pdev->dev; + aspeed->master.dev.release = aspeed_master_release; + aspeed->master.dev.of_node = of_node_get(dev_of_node(&pdev->dev)); + + aspeed->master.n_links = links; + aspeed->master.read = aspeed_master_read; + aspeed->master.write = aspeed_master_write; + aspeed->master.send_break = aspeed_master_break; + aspeed->master.term = aspeed_master_term; + aspeed->master.link_enable = aspeed_master_link_enable; + + dev_set_drvdata(&pdev->dev, aspeed); + + mutex_init(&aspeed->lock); + aspeed_master_init(aspeed); + + rc = fsi_master_register(&aspeed->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(&aspeed->master.dev); + return 0; + +err_release: + clk_disable_unprepare(aspeed->clk); +err_free_aspeed: + kfree(aspeed); + return rc; +} + +static int fsi_master_aspeed_remove(struct platform_device *pdev) +{ + struct fsi_master_aspeed *aspeed = platform_get_drvdata(pdev); + + fsi_master_unregister(&aspeed->master); + clk_disable_unprepare(aspeed->clk); + + return 0; +} + +static const struct of_device_id fsi_master_aspeed_match[] = { + { .compatible = "aspeed,ast2600-fsi-master" }, + { }, +}; +MODULE_DEVICE_TABLE(of, fsi_master_aspeed_match); + +static struct platform_driver fsi_master_aspeed_driver = { + .driver = { + .name = "fsi-master-aspeed", + .of_match_table = fsi_master_aspeed_match, + }, + .probe = fsi_master_aspeed_probe, + .remove = fsi_master_aspeed_remove, +}; + +module_platform_driver(fsi_master_aspeed_driver); +MODULE_LICENSE("GPL"); |