summaryrefslogtreecommitdiffstats
path: root/drivers/bus/vexpress-config.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/bus/vexpress-config.c')
-rw-r--r--drivers/bus/vexpress-config.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
new file mode 100644
index 0000000000..c4e1becbb2
--- /dev/null
+++ b/drivers/bus/vexpress-config.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2014 ARM Limited
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/vexpress.h>
+
+#define SYS_MISC 0x0
+#define SYS_MISC_MASTERSITE (1 << 14)
+
+#define SYS_PROCID0 0x24
+#define SYS_PROCID1 0x28
+#define SYS_HBI_MASK 0xfff
+#define SYS_PROCIDx_HBI_SHIFT 0
+
+#define SYS_CFGDATA 0x40
+
+#define SYS_CFGCTRL 0x44
+#define SYS_CFGCTRL_START (1 << 31)
+#define SYS_CFGCTRL_WRITE (1 << 30)
+#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
+#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
+#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
+#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
+#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
+
+#define SYS_CFGSTAT 0x48
+#define SYS_CFGSTAT_ERR (1 << 1)
+#define SYS_CFGSTAT_COMPLETE (1 << 0)
+
+#define VEXPRESS_SITE_MB 0
+#define VEXPRESS_SITE_DB1 1
+#define VEXPRESS_SITE_DB2 2
+#define VEXPRESS_SITE_MASTER 0xf
+
+struct vexpress_syscfg {
+ struct device *dev;
+ void __iomem *base;
+ struct list_head funcs;
+};
+
+struct vexpress_syscfg_func {
+ struct list_head list;
+ struct vexpress_syscfg *syscfg;
+ struct regmap *regmap;
+ int num_templates;
+ u32 template[]; /* Keep it last! */
+};
+
+struct vexpress_config_bridge_ops {
+ struct regmap * (*regmap_init)(struct device *dev, void *context);
+ void (*regmap_exit)(struct regmap *regmap, void *context);
+};
+
+struct vexpress_config_bridge {
+ struct vexpress_config_bridge_ops *ops;
+ void *context;
+};
+
+
+static DEFINE_MUTEX(vexpress_config_mutex);
+static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
+
+
+static void vexpress_config_set_master(u32 site)
+{
+ vexpress_config_site_master = site;
+}
+
+static void vexpress_config_lock(void *arg)
+{
+ mutex_lock(&vexpress_config_mutex);
+}
+
+static void vexpress_config_unlock(void *arg)
+{
+ mutex_unlock(&vexpress_config_mutex);
+}
+
+
+static void vexpress_config_find_prop(struct device_node *node,
+ const char *name, u32 *val)
+{
+ /* Default value */
+ *val = 0;
+
+ of_node_get(node);
+ while (node) {
+ if (of_property_read_u32(node, name, val) == 0) {
+ of_node_put(node);
+ return;
+ }
+ node = of_get_next_parent(node);
+ }
+}
+
+static int vexpress_config_get_topo(struct device_node *node, u32 *site,
+ u32 *position, u32 *dcc)
+{
+ vexpress_config_find_prop(node, "arm,vexpress,site", site);
+ if (*site == VEXPRESS_SITE_MASTER)
+ *site = vexpress_config_site_master;
+ if (WARN_ON(vexpress_config_site_master == VEXPRESS_SITE_MASTER))
+ return -EINVAL;
+ vexpress_config_find_prop(node, "arm,vexpress,position", position);
+ vexpress_config_find_prop(node, "arm,vexpress,dcc", dcc);
+
+ return 0;
+}
+
+
+static void vexpress_config_devres_release(struct device *dev, void *res)
+{
+ struct vexpress_config_bridge *bridge = dev_get_drvdata(dev->parent);
+ struct regmap *regmap = res;
+
+ bridge->ops->regmap_exit(regmap, bridge->context);
+}
+
+struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
+{
+ struct vexpress_config_bridge *bridge;
+ struct regmap *regmap;
+ struct regmap **res;
+
+ bridge = dev_get_drvdata(dev->parent);
+ if (WARN_ON(!bridge))
+ return ERR_PTR(-EINVAL);
+
+ res = devres_alloc(vexpress_config_devres_release, sizeof(*res),
+ GFP_KERNEL);
+ if (!res)
+ return ERR_PTR(-ENOMEM);
+
+ regmap = (bridge->ops->regmap_init)(dev, bridge->context);
+ if (IS_ERR(regmap)) {
+ devres_free(res);
+ return regmap;
+ }
+
+ *res = regmap;
+ devres_add(dev, res);
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
+
+static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
+ int index, bool write, u32 *data)
+{
+ struct vexpress_syscfg *syscfg = func->syscfg;
+ u32 command, status;
+ int tries;
+ long timeout;
+
+ if (WARN_ON(index >= func->num_templates))
+ return -EINVAL;
+
+ command = readl(syscfg->base + SYS_CFGCTRL);
+ if (WARN_ON(command & SYS_CFGCTRL_START))
+ return -EBUSY;
+
+ command = func->template[index];
+ command |= SYS_CFGCTRL_START;
+ command |= write ? SYS_CFGCTRL_WRITE : 0;
+
+ /* Use a canary for reads */
+ if (!write)
+ *data = 0xdeadbeef;
+
+ dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
+ func, command, *data);
+ writel(*data, syscfg->base + SYS_CFGDATA);
+ writel(0, syscfg->base + SYS_CFGSTAT);
+ writel(command, syscfg->base + SYS_CFGCTRL);
+ mb();
+
+ /* The operation can take ages... Go to sleep, 100us initially */
+ tries = 100;
+ timeout = 100;
+ do {
+ if (!irqs_disabled()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(usecs_to_jiffies(timeout));
+ if (signal_pending(current))
+ return -EINTR;
+ } else {
+ udelay(timeout);
+ }
+
+ status = readl(syscfg->base + SYS_CFGSTAT);
+ if (status & SYS_CFGSTAT_ERR)
+ return -EFAULT;
+
+ if (timeout > 20)
+ timeout -= 20;
+ } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
+ if (WARN_ON_ONCE(!tries))
+ return -ETIMEDOUT;
+
+ if (!write) {
+ *data = readl(syscfg->base + SYS_CFGDATA);
+ dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
+ }
+
+ return 0;
+}
+
+static int vexpress_syscfg_read(void *context, unsigned int index,
+ unsigned int *val)
+{
+ struct vexpress_syscfg_func *func = context;
+
+ return vexpress_syscfg_exec(func, index, false, val);
+}
+
+static int vexpress_syscfg_write(void *context, unsigned int index,
+ unsigned int val)
+{
+ struct vexpress_syscfg_func *func = context;
+
+ return vexpress_syscfg_exec(func, index, true, &val);
+}
+
+static struct regmap_config vexpress_syscfg_regmap_config = {
+ .lock = vexpress_config_lock,
+ .unlock = vexpress_config_unlock,
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_read = vexpress_syscfg_read,
+ .reg_write = vexpress_syscfg_write,
+ .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+
+static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
+ void *context)
+{
+ int err;
+ struct vexpress_syscfg *syscfg = context;
+ struct vexpress_syscfg_func *func;
+ struct property *prop;
+ const __be32 *val = NULL;
+ __be32 energy_quirk[4];
+ int num;
+ u32 site, position, dcc;
+ int i;
+
+ err = vexpress_config_get_topo(dev->of_node, &site,
+ &position, &dcc);
+ if (err)
+ return ERR_PTR(err);
+
+ prop = of_find_property(dev->of_node,
+ "arm,vexpress-sysreg,func", NULL);
+ if (!prop)
+ return ERR_PTR(-EINVAL);
+
+ num = prop->length / sizeof(u32) / 2;
+ val = prop->value;
+
+ /*
+ * "arm,vexpress-energy" function used to be described
+ * by its first device only, now it requires both
+ */
+ if (num == 1 && of_device_is_compatible(dev->of_node,
+ "arm,vexpress-energy")) {
+ num = 2;
+ energy_quirk[0] = *val;
+ energy_quirk[2] = *val++;
+ energy_quirk[1] = *val;
+ energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
+ val = energy_quirk;
+ }
+
+ func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
+ if (!func)
+ return ERR_PTR(-ENOMEM);
+
+ func->syscfg = syscfg;
+ func->num_templates = num;
+
+ for (i = 0; i < num; i++) {
+ u32 function, device;
+
+ function = be32_to_cpup(val++);
+ device = be32_to_cpup(val++);
+
+ dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
+ func, site, position, dcc,
+ function, device);
+
+ func->template[i] = SYS_CFGCTRL_DCC(dcc);
+ func->template[i] |= SYS_CFGCTRL_SITE(site);
+ func->template[i] |= SYS_CFGCTRL_POSITION(position);
+ func->template[i] |= SYS_CFGCTRL_FUNC(function);
+ func->template[i] |= SYS_CFGCTRL_DEVICE(device);
+ }
+
+ vexpress_syscfg_regmap_config.max_register = num - 1;
+
+ func->regmap = regmap_init(dev, NULL, func,
+ &vexpress_syscfg_regmap_config);
+
+ if (IS_ERR(func->regmap)) {
+ void *err = func->regmap;
+
+ kfree(func);
+ return err;
+ }
+
+ list_add(&func->list, &syscfg->funcs);
+
+ return func->regmap;
+}
+
+static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
+{
+ struct vexpress_syscfg *syscfg = context;
+ struct vexpress_syscfg_func *func, *tmp;
+
+ regmap_exit(regmap);
+
+ list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
+ if (func->regmap == regmap) {
+ list_del(&syscfg->funcs);
+ kfree(func);
+ break;
+ }
+ }
+}
+
+static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
+ .regmap_init = vexpress_syscfg_regmap_init,
+ .regmap_exit = vexpress_syscfg_regmap_exit,
+};
+
+
+static int vexpress_syscfg_probe(struct platform_device *pdev)
+{
+ struct vexpress_syscfg *syscfg;
+ struct vexpress_config_bridge *bridge;
+ struct device_node *node;
+ int master;
+ u32 dt_hbi;
+
+ syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
+ if (!syscfg)
+ return -ENOMEM;
+ syscfg->dev = &pdev->dev;
+ INIT_LIST_HEAD(&syscfg->funcs);
+
+ syscfg->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(syscfg->base))
+ return PTR_ERR(syscfg->base);
+
+ bridge = devm_kmalloc(&pdev->dev, sizeof(*bridge), GFP_KERNEL);
+ if (!bridge)
+ return -ENOMEM;
+
+ bridge->ops = &vexpress_syscfg_bridge_ops;
+ bridge->context = syscfg;
+
+ dev_set_drvdata(&pdev->dev, bridge);
+
+ master = readl(syscfg->base + SYS_MISC) & SYS_MISC_MASTERSITE ?
+ VEXPRESS_SITE_DB2 : VEXPRESS_SITE_DB1;
+ vexpress_config_set_master(master);
+
+ /* Confirm board type against DT property, if available */
+ if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) {
+ u32 id = readl(syscfg->base + (master == VEXPRESS_SITE_DB1 ?
+ SYS_PROCID0 : SYS_PROCID1));
+ u32 hbi = (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
+
+ if (WARN_ON(dt_hbi != hbi))
+ dev_warn(&pdev->dev, "DT HBI (%x) is not matching hardware (%x)!\n",
+ dt_hbi, hbi);
+ }
+
+ for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
+ struct device_node *bridge_np;
+
+ bridge_np = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);
+ if (bridge_np != pdev->dev.parent->of_node)
+ continue;
+
+ of_platform_populate(node, NULL, NULL, &pdev->dev);
+ }
+
+ return 0;
+}
+
+static const struct platform_device_id vexpress_syscfg_id_table[] = {
+ { "vexpress-syscfg", },
+ {},
+};
+MODULE_DEVICE_TABLE(platform, vexpress_syscfg_id_table);
+
+static struct platform_driver vexpress_syscfg_driver = {
+ .driver.name = "vexpress-syscfg",
+ .id_table = vexpress_syscfg_id_table,
+ .probe = vexpress_syscfg_probe,
+};
+module_platform_driver(vexpress_syscfg_driver);
+MODULE_LICENSE("GPL v2");