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Diffstat (limited to 'drivers/soc/aspeed/aspeed-lpc-ctrl.c')
-rw-r--r--drivers/soc/aspeed/aspeed-lpc-ctrl.c366
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");