#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[] __counted_by(num_templates);
};
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)
{
*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;
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();
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;
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_flex(*func, template, num);
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);
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_DESCRIPTION("Versatile Express configuration bus");
MODULE_LICENSE("GPL v2");
