mfd: vexpress: Convert custom func API to regmap
Components of the Versatile Express platform (configuration
microcontrollers on motherboard and daughterboards in particular)
talk to each other over a custom configuration bus. They
provide miscellaneous functions (from clock generator control
to energy sensors) which are represented as platform devices
(and Device Tree nodes). The transactions on the bus can
be generated by different "bridges" in the system, some
of which are universal for the whole platform (for the price
of high transfer latencies), others restricted to a subsystem
(but much faster).
Until now drivers for such functions were using custom "func"
API, which is being replaced in this patch by regmap calls.
This required:
* a rework (and move to drivers/bus directory, as suggested
by Samuel and Arnd) of the config bus core, which is much
simpler now and uses device model infrastructure (class)
to keep track of the bridges; non-DT case (soon to be
retired anyway) is simply covered by a special device
registration function
* the new config-bus driver also takes over device population,
so there is no need for special matching table for
of_platform_populate nor "simple-bus" hack in the arm64
model dtsi file (relevant bindings documentation has
been updated); this allows all the vexpress devices
fit into normal device model, making it possible
to remove plenty of early inits and other hacks in
the near future
* adaptation of the syscfg bridge implementation in the
sysreg driver, again making it much simpler; there is
a special case of the "energy" function spanning two
registers, where they should be both defined in the tree
now, but backward compatibility is maintained in the code
* modification of the relevant drivers:
* hwmon - just a straight-forward API change
* power/reset driver - API change
* regulator - API change plus error handling
simplification
* osc clock driver - this one required larger rework
in order to turn in into a standard platform driver
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/mfd/vexpress-sysreg.c b/drivers/mfd/vexpress-sysreg.c
index 35281e8..b4138a7 100644
--- a/drivers/mfd/vexpress-sysreg.c
+++ b/drivers/mfd/vexpress-sysreg.c
@@ -16,8 +16,10 @@
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/of_address.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
+#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/timer.h>
@@ -72,9 +74,18 @@
static void __iomem *vexpress_sysreg_base;
static struct device *vexpress_sysreg_dev;
-static int vexpress_master_site;
+static LIST_HEAD(vexpress_sysreg_config_funcs);
+static struct device *vexpress_sysreg_config_bridge;
+static int vexpress_sysreg_get_master(void)
+{
+ if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
+ return VEXPRESS_SITE_DB2;
+
+ return VEXPRESS_SITE_DB1;
+}
+
void vexpress_flags_set(u32 data)
{
writel(~0, vexpress_sysreg_base + SYS_FLAGSCLR);
@@ -84,7 +95,7 @@
u32 vexpress_get_procid(int site)
{
if (site == VEXPRESS_SITE_MASTER)
- site = vexpress_master_site;
+ site = vexpress_sysreg_get_master();
return readl(vexpress_sysreg_base + (site == VEXPRESS_SITE_DB1 ?
SYS_PROCID0 : SYS_PROCID1));
@@ -114,130 +125,33 @@
}
-static void vexpress_sysreg_find_prop(struct device_node *node,
- const char *name, u32 *val)
-{
- 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);
- }
-}
-
-unsigned __vexpress_get_site(struct device *dev, struct device_node *node)
-{
- u32 site = 0;
-
- WARN_ON(dev && node && dev->of_node != node);
- if (dev && !node)
- node = dev->of_node;
-
- if (node) {
- vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
- } else if (dev && dev->bus == &platform_bus_type) {
- struct platform_device *pdev = to_platform_device(dev);
-
- if (pdev->num_resources == 1 &&
- pdev->resource[0].flags == IORESOURCE_BUS)
- site = pdev->resource[0].start;
- } else if (dev && strncmp(dev_name(dev), "ct:", 3) == 0) {
- site = VEXPRESS_SITE_MASTER;
- }
-
- if (site == VEXPRESS_SITE_MASTER)
- site = vexpress_master_site;
-
- return site;
-}
-
-
struct vexpress_sysreg_config_func {
- u32 template;
- u32 device;
+ struct list_head list;
+ struct regmap *regmap;
+ int num_templates;
+ u32 template[0]; /* Keep this last */
};
-static struct vexpress_config_bridge *vexpress_sysreg_config_bridge;
-static struct timer_list vexpress_sysreg_config_timer;
-static u32 *vexpress_sysreg_config_data;
-static int vexpress_sysreg_config_tries;
-
-static void *vexpress_sysreg_config_func_get(struct device *dev,
- struct device_node *node)
+static int vexpress_sysreg_config_exec(struct vexpress_sysreg_config_func *func,
+ int index, bool write, u32 *data)
{
- struct vexpress_sysreg_config_func *config_func;
- u32 site = 0;
- u32 position = 0;
- u32 dcc = 0;
- u32 func_device[2];
- int err = -EFAULT;
-
- if (node) {
- of_node_get(node);
- vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
- vexpress_sysreg_find_prop(node, "arm,vexpress,position",
- &position);
- vexpress_sysreg_find_prop(node, "arm,vexpress,dcc", &dcc);
- err = of_property_read_u32_array(node,
- "arm,vexpress-sysreg,func", func_device,
- ARRAY_SIZE(func_device));
- of_node_put(node);
- } else if (dev && dev->bus == &platform_bus_type) {
- struct platform_device *pdev = to_platform_device(dev);
-
- if (pdev->num_resources == 1 &&
- pdev->resource[0].flags == IORESOURCE_BUS) {
- site = pdev->resource[0].start;
- func_device[0] = pdev->resource[0].end;
- func_device[1] = pdev->id;
- err = 0;
- }
- }
- if (err)
- return NULL;
-
- config_func = kzalloc(sizeof(*config_func), GFP_KERNEL);
- if (!config_func)
- return NULL;
-
- config_func->template = SYS_CFGCTRL_DCC(dcc);
- config_func->template |= SYS_CFGCTRL_FUNC(func_device[0]);
- config_func->template |= SYS_CFGCTRL_SITE(site == VEXPRESS_SITE_MASTER ?
- vexpress_master_site : site);
- config_func->template |= SYS_CFGCTRL_POSITION(position);
- config_func->device |= func_device[1];
-
- dev_dbg(vexpress_sysreg_dev, "func 0x%p = 0x%x, %d\n", config_func,
- config_func->template, config_func->device);
-
- return config_func;
-}
-
-static void vexpress_sysreg_config_func_put(void *func)
-{
- kfree(func);
-}
-
-static int vexpress_sysreg_config_func_exec(void *func, int offset,
- bool write, u32 *data)
-{
- int status;
- struct vexpress_sysreg_config_func *config_func = func;
- u32 command;
+ u32 command, status;
+ int tries;
+ long timeout;
if (WARN_ON(!vexpress_sysreg_base))
return -ENOENT;
+ if (WARN_ON(index > func->num_templates))
+ return -EINVAL;
+
command = readl(vexpress_sysreg_base + SYS_CFGCTRL);
if (WARN_ON(command & SYS_CFGCTRL_START))
return -EBUSY;
- command = SYS_CFGCTRL_START;
+ command = func->template[index];
+ command |= SYS_CFGCTRL_START;
command |= write ? SYS_CFGCTRL_WRITE : 0;
- command |= config_func->template;
- command |= SYS_CFGCTRL_DEVICE(config_func->device + offset);
/* Use a canary for reads */
if (!write)
@@ -250,90 +164,190 @@
writel(command, vexpress_sysreg_base + SYS_CFGCTRL);
mb();
- if (vexpress_sysreg_dev) {
- /* Schedule completion check */
- if (!write)
- vexpress_sysreg_config_data = data;
- vexpress_sysreg_config_tries = 100;
- mod_timer(&vexpress_sysreg_config_timer,
- jiffies + usecs_to_jiffies(100));
- status = VEXPRESS_CONFIG_STATUS_WAIT;
- } else {
- /* Early execution, no timer available, have to spin */
- u32 cfgstat;
+ /* The operation can take ages... Go to sleep, 100us initially */
+ tries = 100;
+ timeout = 100;
+ do {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(usecs_to_jiffies(timeout));
+ if (signal_pending(current))
+ return -EINTR;
- do {
- cpu_relax();
- cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
- } while (!cfgstat);
+ status = readl(vexpress_sysreg_base + SYS_CFGSTAT);
+ if (status & SYS_CFGSTAT_ERR)
+ return -EFAULT;
- if (!write && (cfgstat & SYS_CFGSTAT_COMPLETE))
- *data = readl(vexpress_sysreg_base + SYS_CFGDATA);
- status = VEXPRESS_CONFIG_STATUS_DONE;
+ if (timeout > 20)
+ timeout -= 20;
+ } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
+ if (WARN_ON_ONCE(!tries))
+ return -ETIMEDOUT;
- if (cfgstat & SYS_CFGSTAT_ERR)
- status = -EINVAL;
+ if (!write) {
+ *data = readl(vexpress_sysreg_base + SYS_CFGDATA);
+ dev_dbg(vexpress_sysreg_dev, "func %p, read data %x\n",
+ func, *data);
}
- return status;
+ return 0;
}
-struct vexpress_config_bridge_info vexpress_sysreg_config_bridge_info = {
- .name = "vexpress-sysreg",
- .func_get = vexpress_sysreg_config_func_get,
- .func_put = vexpress_sysreg_config_func_put,
- .func_exec = vexpress_sysreg_config_func_exec,
+static int vexpress_sysreg_config_read(void *context, unsigned int index,
+ unsigned int *val)
+{
+ struct vexpress_sysreg_config_func *func = context;
+
+ return vexpress_sysreg_config_exec(func, index, false, val);
+}
+
+static int vexpress_sysreg_config_write(void *context, unsigned int index,
+ unsigned int val)
+{
+ struct vexpress_sysreg_config_func *func = context;
+
+ return vexpress_sysreg_config_exec(func, index, true, &val);
+}
+
+struct regmap_config vexpress_sysreg_regmap_config = {
+ .lock = vexpress_config_lock,
+ .unlock = vexpress_config_unlock,
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_read = vexpress_sysreg_config_read,
+ .reg_write = vexpress_sysreg_config_write,
+ .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
};
-static void vexpress_sysreg_config_complete(unsigned long data)
+static struct regmap *vexpress_sysreg_config_regmap_init(struct device *dev,
+ void *context)
{
- int status = VEXPRESS_CONFIG_STATUS_DONE;
- u32 cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct vexpress_sysreg_config_func *func;
+ struct property *prop;
+ const __be32 *val = NULL;
+ __be32 energy_quirk[4];
+ int num;
+ u32 site, position, dcc;
+ int err;
+ int i;
- if (cfgstat & SYS_CFGSTAT_ERR)
- status = -EINVAL;
- if (!vexpress_sysreg_config_tries--)
- status = -ETIMEDOUT;
+ if (dev->of_node) {
+ err = vexpress_config_get_topo(dev->of_node, &site, &position,
+ &dcc);
+ if (err)
+ return ERR_PTR(err);
- if (status < 0) {
- dev_err(vexpress_sysreg_dev, "error %d\n", status);
- } else if (!(cfgstat & SYS_CFGSTAT_COMPLETE)) {
- mod_timer(&vexpress_sysreg_config_timer,
- jiffies + usecs_to_jiffies(50));
- return;
+ 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;
+ } else {
+ if (pdev->num_resources != 1 ||
+ pdev->resource[0].flags != IORESOURCE_BUS)
+ return ERR_PTR(-EFAULT);
+
+ site = pdev->resource[0].start;
+ if (site == VEXPRESS_SITE_MASTER)
+ site = vexpress_sysreg_get_master();
+ position = 0;
+ dcc = 0;
+ num = 1;
}
- if (vexpress_sysreg_config_data) {
- *vexpress_sysreg_config_data = readl(vexpress_sysreg_base +
- SYS_CFGDATA);
- dev_dbg(vexpress_sysreg_dev, "read data %x\n",
- *vexpress_sysreg_config_data);
- vexpress_sysreg_config_data = NULL;
+ /*
+ * "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;
}
- vexpress_config_complete(vexpress_sysreg_config_bridge, status);
-}
+ func = kzalloc(sizeof(*func) + sizeof(*func->template) * num,
+ GFP_KERNEL);
+ if (!func)
+ return NULL;
+ func->num_templates = num;
-void vexpress_sysreg_setup(struct device_node *node)
-{
- if (WARN_ON(!vexpress_sysreg_base))
- return;
+ for (i = 0; i < num; i++) {
+ u32 function, device;
- if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
- vexpress_master_site = VEXPRESS_SITE_DB2;
+ if (dev->of_node) {
+ function = be32_to_cpup(val++);
+ device = be32_to_cpup(val++);
+ } else {
+ function = pdev->resource[0].end;
+ device = pdev->id;
+ }
+
+ 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_sysreg_regmap_config.max_register = num - 1;
+
+ func->regmap = regmap_init(dev, NULL, func,
+ &vexpress_sysreg_regmap_config);
+
+ if (IS_ERR(func->regmap))
+ kfree(func);
else
- vexpress_master_site = VEXPRESS_SITE_DB1;
+ list_add(&func->list, &vexpress_sysreg_config_funcs);
- vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
- node, &vexpress_sysreg_config_bridge_info);
- WARN_ON(!vexpress_sysreg_config_bridge);
+ return func->regmap;
}
+static void vexpress_sysreg_config_regmap_exit(struct regmap *regmap,
+ void *context)
+{
+ struct vexpress_sysreg_config_func *func, *tmp;
+
+ regmap_exit(regmap);
+
+ list_for_each_entry_safe(func, tmp, &vexpress_sysreg_config_funcs,
+ list) {
+ if (func->regmap == regmap) {
+ list_del(&vexpress_sysreg_config_funcs);
+ kfree(func);
+ break;
+ }
+ }
+}
+
+static struct vexpress_config_bridge_ops vexpress_sysreg_config_bridge_ops = {
+ .regmap_init = vexpress_sysreg_config_regmap_init,
+ .regmap_exit = vexpress_sysreg_config_regmap_exit,
+};
+
+int vexpress_sysreg_config_device_register(struct platform_device *pdev)
+{
+ pdev->dev.parent = vexpress_sysreg_config_bridge;
+
+ return platform_device_register(pdev);
+}
+
+
void __init vexpress_sysreg_early_init(void __iomem *base)
{
vexpress_sysreg_base = base;
- vexpress_sysreg_setup(NULL);
+ vexpress_config_set_master(vexpress_sysreg_get_master());
}
void __init vexpress_sysreg_of_early_init(void)
@@ -344,10 +358,14 @@
return;
node = of_find_compatible_node(NULL, NULL, "arm,vexpress-sysreg");
- if (node) {
- vexpress_sysreg_base = of_iomap(node, 0);
- vexpress_sysreg_setup(node);
- }
+ if (WARN_ON(!node))
+ return;
+
+ vexpress_sysreg_base = of_iomap(node, 0);
+ if (WARN_ON(!vexpress_sysreg_base))
+ return;
+
+ vexpress_config_set_master(vexpress_sysreg_get_master());
}
@@ -470,28 +488,22 @@
return -EBUSY;
}
- if (!vexpress_sysreg_base) {
+ if (!vexpress_sysreg_base)
vexpress_sysreg_base = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
- vexpress_sysreg_setup(pdev->dev.of_node);
- }
if (!vexpress_sysreg_base) {
dev_err(&pdev->dev, "Failed to obtain base address!\n");
return -EFAULT;
}
- setup_timer(&vexpress_sysreg_config_timer,
- vexpress_sysreg_config_complete, 0);
-
+ vexpress_config_set_master(vexpress_sysreg_get_master());
vexpress_sysreg_dev = &pdev->dev;
#ifdef CONFIG_GPIOLIB
vexpress_sysreg_gpio_chip.dev = &pdev->dev;
err = gpiochip_add(&vexpress_sysreg_gpio_chip);
if (err) {
- vexpress_config_bridge_unregister(
- vexpress_sysreg_config_bridge);
dev_err(&pdev->dev, "Failed to register GPIO chip! (%d)\n",
err);
return err;
@@ -502,6 +514,10 @@
sizeof(vexpress_sysreg_leds_pdata));
#endif
+ vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
+ &pdev->dev, &vexpress_sysreg_config_bridge_ops, NULL);
+ WARN_ON(!vexpress_sysreg_config_bridge);
+
device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);
return 0;
@@ -522,7 +538,12 @@
static int __init vexpress_sysreg_init(void)
{
- vexpress_sysreg_of_early_init();
+ struct device_node *node;
+
+ /* Need the sysreg early, before any other device... */
+ for_each_matching_node(node, vexpress_sysreg_match)
+ of_platform_device_create(node, NULL, NULL);
+
return platform_driver_register(&vexpress_sysreg_driver);
}
core_initcall(vexpress_sysreg_init);