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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/soc/aspeed/aspeed-lpc-ctrl.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/soc/aspeed/aspeed-lpc-ctrl.c')
-rw-r--r-- | drivers/soc/aspeed/aspeed-lpc-ctrl.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c new file mode 100644 index 000000000..258894ed2 --- /dev/null +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2017 IBM Corporation + */ + +#include <linux/clk.h> +#include <linux/log2.h> +#include <linux/mfd/syscon.h> +#include <linux/miscdevice.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/poll.h> +#include <linux/regmap.h> + +#include <linux/aspeed-lpc-ctrl.h> + +#define DEVICE_NAME "aspeed-lpc-ctrl" + +#define HICR5 0x80 +#define HICR5_ENL2H BIT(8) +#define HICR5_ENFWH BIT(10) + +#define HICR6 0x84 +#define SW_FWH2AHB BIT(17) + +#define HICR7 0x88 +#define HICR8 0x8c + +struct aspeed_lpc_ctrl { + struct miscdevice miscdev; + struct regmap *regmap; + struct clk *clk; + phys_addr_t mem_base; + resource_size_t mem_size; + u32 pnor_size; + u32 pnor_base; + bool fwh2ahb; + struct regmap *scu; +}; + +static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) +{ + return container_of(file->private_data, struct aspeed_lpc_ctrl, + miscdev); +} + +static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); + unsigned long vsize = vma->vm_end - vma->vm_start; + pgprot_t prot = vma->vm_page_prot; + + if (vma->vm_pgoff + vma_pages(vma) > lpc_ctrl->mem_size >> PAGE_SHIFT) + return -EINVAL; + + /* ast2400/2500 AHB accesses are not cache coherent */ + prot = pgprot_noncached(prot); + + if (remap_pfn_range(vma, vma->vm_start, + (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, + vsize, prot)) + return -EAGAIN; + + return 0; +} + +static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, + unsigned long param) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); + struct device *dev = file->private_data; + void __user *p = (void __user *)param; + struct aspeed_lpc_ctrl_mapping map; + u32 addr; + u32 size; + long rc; + + if (copy_from_user(&map, p, sizeof(map))) + return -EFAULT; + + if (map.flags != 0) + return -EINVAL; + + switch (cmd) { + case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: + /* The flash windows don't report their size */ + if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) + return -EINVAL; + + /* Support more than one window id in the future */ + if (map.window_id != 0) + return -EINVAL; + + /* If memory-region is not described in device tree */ + if (!lpc_ctrl->mem_size) { + dev_dbg(dev, "Didn't find reserved memory\n"); + return -ENXIO; + } + + map.size = lpc_ctrl->mem_size; + + return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; + case ASPEED_LPC_CTRL_IOCTL_MAP: + + /* + * The top half of HICR7 is the MSB of the BMC address of the + * mapping. + * The bottom half of HICR7 is the MSB of the HOST LPC + * firmware space address of the mapping. + * + * The 1 bits in the top of half of HICR8 represent the bits + * (in the requested address) that should be ignored and + * replaced with those from the top half of HICR7. + * The 1 bits in the bottom half of HICR8 represent the bits + * (in the requested address) that should be kept and pass + * into the BMC address space. + */ + + /* + * It doesn't make sense to talk about a size or offset with + * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 + * bits of addresses and sizes. + */ + + if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) + return -EINVAL; + + /* + * Because of the way the masks work in HICR8 offset has to + * be a multiple of size. + */ + if (map.offset & (map.size - 1)) + return -EINVAL; + + if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { + if (!lpc_ctrl->pnor_size) { + dev_dbg(dev, "Didn't find host pnor flash\n"); + return -ENXIO; + } + addr = lpc_ctrl->pnor_base; + size = lpc_ctrl->pnor_size; + } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { + /* If memory-region is not described in device tree */ + if (!lpc_ctrl->mem_size) { + dev_dbg(dev, "Didn't find reserved memory\n"); + return -ENXIO; + } + addr = lpc_ctrl->mem_base; + size = lpc_ctrl->mem_size; + } else { + return -EINVAL; + } + + /* Check overflow first! */ + if (map.offset + map.size < map.offset || + map.offset + map.size > size) + return -EINVAL; + + if (map.size == 0 || map.size > size) + return -EINVAL; + + addr += map.offset; + + /* + * addr (host lpc address) is safe regardless of values. This + * simply changes the address the host has to request on its + * side of the LPC bus. This cannot impact the hosts own + * memory space by surprise as LPC specific accessors are + * required. The only strange thing that could be done is + * setting the lower 16 bits but the shift takes care of that. + */ + + rc = regmap_write(lpc_ctrl->regmap, HICR7, + (addr | (map.addr >> 16))); + if (rc) + return rc; + + rc = regmap_write(lpc_ctrl->regmap, HICR8, + (~(map.size - 1)) | ((map.size >> 16) - 1)); + if (rc) + return rc; + + /* + * Switch to FWH2AHB mode, AST2600 only. + */ + if (lpc_ctrl->fwh2ahb) { + /* + * Enable FWH2AHB in SCU debug control register 2. This + * does not turn it on, but makes it available for it + * to be configured in HICR6. + */ + regmap_update_bits(lpc_ctrl->scu, 0x0D8, BIT(2), 0); + + /* + * The other bits in this register are interrupt status bits + * that are cleared by writing 1. As we don't want to clear + * them, set only the bit of interest. + */ + regmap_write(lpc_ctrl->regmap, HICR6, SW_FWH2AHB); + } + + /* + * Enable LPC FHW cycles. This is required for the host to + * access the regions specified. + */ + return regmap_update_bits(lpc_ctrl->regmap, HICR5, + HICR5_ENFWH | HICR5_ENL2H, + HICR5_ENFWH | HICR5_ENL2H); + } + + return -EINVAL; +} + +static const struct file_operations aspeed_lpc_ctrl_fops = { + .owner = THIS_MODULE, + .mmap = aspeed_lpc_ctrl_mmap, + .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, +}; + +static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) +{ + struct aspeed_lpc_ctrl *lpc_ctrl; + struct device_node *node; + struct resource resm; + struct device *dev; + struct device_node *np; + int rc; + + dev = &pdev->dev; + + lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); + if (!lpc_ctrl) + return -ENOMEM; + + /* If flash is described in device tree then store */ + node = of_parse_phandle(dev->of_node, "flash", 0); + if (!node) { + dev_dbg(dev, "Didn't find host pnor flash node\n"); + } else { + rc = of_address_to_resource(node, 1, &resm); + of_node_put(node); + if (rc) { + dev_err(dev, "Couldn't address to resource for flash\n"); + return rc; + } + + lpc_ctrl->pnor_size = resource_size(&resm); + lpc_ctrl->pnor_base = resm.start; + } + + + dev_set_drvdata(&pdev->dev, lpc_ctrl); + + /* If memory-region is described in device tree then store */ + node = of_parse_phandle(dev->of_node, "memory-region", 0); + if (!node) { + dev_dbg(dev, "Didn't find reserved memory\n"); + } else { + rc = of_address_to_resource(node, 0, &resm); + of_node_put(node); + if (rc) { + dev_err(dev, "Couldn't address to resource for reserved memory\n"); + return -ENXIO; + } + + lpc_ctrl->mem_size = resource_size(&resm); + lpc_ctrl->mem_base = resm.start; + + if (!is_power_of_2(lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory size must be a power of 2, got %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } + + if (!IS_ALIGNED(lpc_ctrl->mem_base, lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory must be naturally aligned for size %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } + } + + np = pdev->dev.parent->of_node; + if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") && + !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") && + !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) { + dev_err(dev, "unsupported LPC device binding\n"); + return -ENODEV; + } + + lpc_ctrl->regmap = syscon_node_to_regmap(np); + if (IS_ERR(lpc_ctrl->regmap)) { + dev_err(dev, "Couldn't get regmap\n"); + return -ENODEV; + } + + if (of_device_is_compatible(dev->of_node, "aspeed,ast2600-lpc-ctrl")) { + lpc_ctrl->fwh2ahb = true; + + lpc_ctrl->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2600-scu"); + if (IS_ERR(lpc_ctrl->scu)) { + dev_err(dev, "couldn't find scu\n"); + return PTR_ERR(lpc_ctrl->scu); + } + } + + lpc_ctrl->clk = devm_clk_get(dev, NULL); + if (IS_ERR(lpc_ctrl->clk)) + return dev_err_probe(dev, PTR_ERR(lpc_ctrl->clk), + "couldn't get clock\n"); + rc = clk_prepare_enable(lpc_ctrl->clk); + if (rc) { + dev_err(dev, "couldn't enable clock\n"); + return rc; + } + + lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; + lpc_ctrl->miscdev.name = DEVICE_NAME; + lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; + lpc_ctrl->miscdev.parent = dev; + rc = misc_register(&lpc_ctrl->miscdev); + if (rc) { + dev_err(dev, "Unable to register device\n"); + goto err; + } + + return 0; + +err: + clk_disable_unprepare(lpc_ctrl->clk); + return rc; +} + +static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); + + misc_deregister(&lpc_ctrl->miscdev); + clk_disable_unprepare(lpc_ctrl->clk); + + return 0; +} + +static const struct of_device_id aspeed_lpc_ctrl_match[] = { + { .compatible = "aspeed,ast2400-lpc-ctrl" }, + { .compatible = "aspeed,ast2500-lpc-ctrl" }, + { .compatible = "aspeed,ast2600-lpc-ctrl" }, + { }, +}; + +static struct platform_driver aspeed_lpc_ctrl_driver = { + .driver = { + .name = DEVICE_NAME, + .of_match_table = aspeed_lpc_ctrl_match, + }, + .probe = aspeed_lpc_ctrl_probe, + .remove = aspeed_lpc_ctrl_remove, +}; + +module_platform_driver(aspeed_lpc_ctrl_driver); + +MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); +MODULE_DESCRIPTION("Control for ASPEED LPC HOST to BMC mappings"); |