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>

1 files changed, 19 insertions, 60 deletions

diff --git a/include/linux/vexpress.h b/include/linux/vexpress.h
index 617c01b8f74a..6b206ba6aa0e 100644
--- a/include/linux/vexpress.h
+++ b/include/linux/vexpress.h
@@ -15,16 +15,15 @@
 #define _LINUX_VEXPRESS_H
 
 #include <linux/device.h>
+#include <linux/platform_device.h>
 #include <linux/reboot.h>
+#include <linux/regmap.h>
 
 #define VEXPRESS_SITE_MB		0
 #define VEXPRESS_SITE_DB1		1
 #define VEXPRESS_SITE_DB2		2
 #define VEXPRESS_SITE_MASTER		0xf
 
-#define VEXPRESS_CONFIG_STATUS_DONE	0
-#define VEXPRESS_CONFIG_STATUS_WAIT	1
-
 #define VEXPRESS_GPIO_MMC_CARDIN	0
 #define VEXPRESS_GPIO_MMC_WPROT		1
 #define VEXPRESS_GPIO_FLASH_WPn		2
@@ -44,63 +43,30 @@
 	.flags = IORESOURCE_BUS,	\
 }
 
-/* Config bridge API */
+/* Config infrastructure */
 
-/**
- * struct vexpress_config_bridge_info - description of the platform
- * configuration infrastructure bridge.
- *
- * @name:	Bridge name
- *
- * @func_get:	Obtains pointer to a configuration function for a given
- *		device or a Device Tree node, to be used with @func_put
- *		and @func_exec. The node pointer should take precedence
- *		over device pointer when both are passed.
- *
- * @func_put:	Tells the bridge that the function will not be used any
- *		more, so all allocated resources can be released.
- *
- * @func_exec:	Executes a configuration function read or write operation.
- *		The offset selects a 32 bit word of the value accessed.
- *		Must return VEXPRESS_CONFIG_STATUS_DONE when operation
- *		is finished immediately, VEXPRESS_CONFIG_STATUS_WAIT when
- *		will be completed in some time or negative value in case
- *		of error.
- */
-struct vexpress_config_bridge_info {
-	const char *name;
-	void *(*func_get)(struct device *dev, struct device_node *node);
-	void (*func_put)(void *func);
-	int (*func_exec)(void *func, int offset, bool write, u32 *data);
-};
+void vexpress_config_set_master(u32 site);
+u32 vexpress_config_get_master(void);
 
-struct vexpress_config_bridge;
+void vexpress_config_lock(void *arg);
+void vexpress_config_unlock(void *arg);
 
-struct vexpress_config_bridge *vexpress_config_bridge_register(
-		struct device_node *node,
-		struct vexpress_config_bridge_info *info);
-void vexpress_config_bridge_unregister(struct vexpress_config_bridge *bridge);
+int vexpress_config_get_topo(struct device_node *node, u32 *site,
+		u32 *position, u32 *dcc);
 
-void vexpress_config_complete(struct vexpress_config_bridge *bridge,
-		int status);
+/* Config bridge API */
 
-/* Config function API */
+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_func;
+struct device *vexpress_config_bridge_register(struct device *parent,
+		struct vexpress_config_bridge_ops *ops, void *context);
 
-struct vexpress_config_func *__vexpress_config_func_get(struct device *dev,
-		struct device_node *node);
-#define vexpress_config_func_get_by_dev(dev) \
-		__vexpress_config_func_get(dev, NULL)
-#define vexpress_config_func_get_by_node(node) \
-		__vexpress_config_func_get(NULL, node)
-void vexpress_config_func_put(struct vexpress_config_func *func);
+/* Config regmap API */
 
-/* Both may sleep! */
-int vexpress_config_read(struct vexpress_config_func *func, int offset,
-		u32 *data);
-int vexpress_config_write(struct vexpress_config_func *func, int offset,
-		u32 data);
+struct regmap *devm_regmap_init_vexpress_config(struct device *dev);
 
 /* Platform control */
 
@@ -109,19 +75,12 @@ u32 vexpress_get_hbi(int site);
 void *vexpress_get_24mhz_clock_base(void);
 void vexpress_flags_set(u32 data);
 
-#define vexpress_get_site_by_node(node) __vexpress_get_site(NULL, node)
-#define vexpress_get_site_by_dev(dev) __vexpress_get_site(dev, NULL)
-unsigned __vexpress_get_site(struct device *dev, struct device_node *node);
-
 void vexpress_sysreg_early_init(void __iomem *base);
 void vexpress_sysreg_of_early_init(void);
+int vexpress_sysreg_config_device_register(struct platform_device *pdev);
 
 /* Clocks */
 
-struct clk *vexpress_osc_setup(struct device *dev);
-void vexpress_osc_of_setup(struct device_node *node);
-
 void vexpress_clk_init(void __iomem *sp810_base);
-void vexpress_clk_of_init(void);
 
 #endif