[PATCH] 3/5 powerpc: Add platform functions interpreter

This is the platform function interpreter itself along with the backends
for UniN/U3/U4, mac-io, GPIOs and i2c. It adds the ability to execute
those do-platform-* scripts in the device-tree (at least for most
devices for which a backend is provided). This should replace the clock
spreading hacks properly. It might also have an impact on all sort of
machines since some of the scripts marked "at init" will now be executed
on boot (or some other on sleep/wakeup), those will possibly do things
that the kernel didn't do at all, like setting some values into some i2c
devices (changing thermal sensor calibration or conversion rate) etc...
Thus regression testing is MUCH welcome. Also loook for errors in dmesg.
That's also why I've left rather verbose debugging enabled in this
version of the patch.

(I do expect some Windtunnel G4s to show some errors as they have an i2c
clock chip on the PMU bus that uses some primitives that the i2c backend
doesn't implement yet. I really need users that have one of those
machine to come back to me so we can get that done right, though the
errors themselves should be harmless, I suspect the machine might not
run at full speed).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 275 insertions, 0 deletions

diff --git a/include/asm-powerpc/pmac_feature.h b/include/asm-powerpc/pmac_feature.h
index e654ad0e5b42..3221628130c4 100644
--- a/include/asm-powerpc/pmac_feature.h
+++ b/include/asm-powerpc/pmac_feature.h
@@ -374,5 +374,24 @@ extern struct macio_chip* macio_find(struct device_node* child, int type);
 #define MACIO_IN8(r)            (in_8(MACIO_FCR8(macio,r)))
 #define MACIO_OUT8(r,v)         (out_8(MACIO_FCR8(macio,r), (v)))
 
+/*
+ * Those are exported by pmac feature for internal use by arch code
+ * only like the platform function callbacks, do not use directly in drivers
+ */
+extern spinlock_t feature_lock;
+extern struct device_node *uninorth_node;
+extern u32 __iomem *uninorth_base;
+
+/*
+ * Uninorth reg. access. Note that Uni-N regs are big endian
+ */
+
+#define UN_REG(r)       (uninorth_base + ((r) >> 2))
+#define UN_IN(r)        (in_be32(UN_REG(r)))
+#define UN_OUT(r,v)     (out_be32(UN_REG(r), (v)))
+#define UN_BIS(r,v)     (UN_OUT((r), UN_IN(r) | (v)))
+#define UN_BIC(r,v)     (UN_OUT((r), UN_IN(r) & ~(v)))
+
+
 #endif /* __PPC_ASM_PMAC_FEATURE_H */
 #endif /* __KERNEL__ */
diff --git a/include/asm-powerpc/pmac_low_i2c.h b/include/asm-powerpc/pmac_low_i2c.h
index 480018f41e1a..131011bd7e76 100644
--- a/include/asm-powerpc/pmac_low_i2c.h
+++ b/include/asm-powerpc/pmac_low_i2c.h
@@ -99,6 +99,9 @@ extern int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode);
 extern int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
                          u32 subaddr, u8 *data,  int len);
 
+/* Suspend/resume code called by via-pmu directly for now */
+extern void pmac_pfunc_i2c_suspend(void);
+extern void pmac_pfunc_i2c_resume(void);
 
 #endif /* __KERNEL__ */
 #endif /* __PMAC_LOW_I2C_H__ */
diff --git a/include/asm-powerpc/pmac_pfunc.h b/include/asm-powerpc/pmac_pfunc.h
new file mode 100644
index 000000000000..d9728c80f86d
--- /dev/null
+++ b/include/asm-powerpc/pmac_pfunc.h
@@ -0,0 +1,253 @@
+#ifndef __PMAC_PFUNC_H__
+#define __PMAC_PFUNC_H__
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+/* Flags in command lists */
+#define PMF_FLAGS_ON_INIT               0x80000000u
+#define PMF_FLGAS_ON_TERM               0x40000000u
+#define PMF_FLAGS_ON_SLEEP              0x20000000u
+#define PMF_FLAGS_ON_WAKE               0x10000000u
+#define PMF_FLAGS_ON_DEMAND             0x08000000u
+#define PMF_FLAGS_INT_GEN               0x04000000u
+#define PMF_FLAGS_HIGH_SPEED            0x02000000u
+#define PMF_FLAGS_LOW_SPEED             0x01000000u
+#define PMF_FLAGS_SIDE_EFFECTS          0x00800000u
+
+/*
+ * Arguments to a platform function call.
+ *
+ * NOTE: By convention, pointer arguments point to an u32
+ */
+struct pmf_args {
+        union {
+                u32 v;
+                u32 *p;
+        } u[4];
+        unsigned int count;
+};
+
+/*
+ * A driver capable of interpreting commands provides a handlers
+ * structure filled with whatever handlers are implemented by this
+ * driver. Non implemented handlers are left NULL.
+ *
+ * PMF_STD_ARGS are the same arguments that are passed to the parser
+ * and that gets passed back to the various handlers.
+ *
+ * Interpreting a given function always start with a begin() call which
+ * returns an instance data to be passed around subsequent calls, and
+ * ends with an end() call. This allows the low level driver to implement
+ * locking policy or per-function instance data.
+ *
+ * For interrupt capable functions, irq_enable() is called when a client
+ * registers, and irq_disable() is called when the last client unregisters
+ * Note that irq_enable & irq_disable are called within a semaphore held
+ * by the core, thus you should not try to register yourself to some other
+ * pmf interrupt during those calls.
+ */
+
+#define PMF_STD_ARGS    struct pmf_function *func, void *instdata, \
+                        struct pmf_args *args
+
+struct pmf_function;
+
+struct pmf_handlers {
+        void * (*begin)(struct pmf_function *func, struct pmf_args *args);
+        void (*end)(struct pmf_function *func, void *instdata);
+
+        int (*irq_enable)(struct pmf_function *func);
+        int (*irq_disable)(struct pmf_function *func);
+
+        int (*write_gpio)(PMF_STD_ARGS, u8 value, u8 mask);
+        int (*read_gpio)(PMF_STD_ARGS, u8 mask, int rshift, u8 xor);
+
+        int (*write_reg32)(PMF_STD_ARGS, u32 offset, u32 value, u32 mask);
+        int (*read_reg32)(PMF_STD_ARGS, u32 offset);
+        int (*write_reg16)(PMF_STD_ARGS, u32 offset, u16 value, u16 mask);
+        int (*read_reg16)(PMF_STD_ARGS, u32 offset);
+        int (*write_reg8)(PMF_STD_ARGS, u32 offset, u8 value, u8 mask);
+        int (*read_reg8)(PMF_STD_ARGS, u32 offset);
+
+        int (*delay)(PMF_STD_ARGS, u32 duration);
+
+        int (*wait_reg32)(PMF_STD_ARGS, u32 offset, u32 value, u32 mask);
+        int (*wait_reg16)(PMF_STD_ARGS, u32 offset, u16 value, u16 mask);
+        int (*wait_reg8)(PMF_STD_ARGS, u32 offset, u8 value, u8 mask);
+
+        int (*read_i2c)(PMF_STD_ARGS, u32 len);
+        int (*write_i2c)(PMF_STD_ARGS, u32 len, const u8 *data);
+        int (*rmw_i2c)(PMF_STD_ARGS, u32 masklen, u32 valuelen, u32 totallen,
+                       const u8 *maskdata, const u8 *valuedata);
+
+        int (*read_cfg)(PMF_STD_ARGS, u32 offset, u32 len);
+        int (*write_cfg)(PMF_STD_ARGS, u32 offset, u32 len, const u8 *data);
+        int (*rmw_cfg)(PMF_STD_ARGS, u32 offset, u32 masklen, u32 valuelen,
+                       u32 totallen, const u8 *maskdata, const u8 *valuedata);
+
+        int (*read_i2c_sub)(PMF_STD_ARGS, u8 subaddr, u32 len);
+        int (*write_i2c_sub)(PMF_STD_ARGS, u8 subaddr, u32 len, const u8 *data);
+        int (*set_i2c_mode)(PMF_STD_ARGS, int mode);
+        int (*rmw_i2c_sub)(PMF_STD_ARGS, u8 subaddr, u32 masklen, u32 valuelen,
+                           u32 totallen, const u8 *maskdata,
+                           const u8 *valuedata);
+
+        int (*read_reg32_msrx)(PMF_STD_ARGS, u32 offset, u32 mask, u32 shift,
+                               u32 xor);
+        int (*read_reg16_msrx)(PMF_STD_ARGS, u32 offset, u32 mask, u32 shift,
+                               u32 xor);
+        int (*read_reg8_msrx)(PMF_STD_ARGS, u32 offset, u32 mask, u32 shift,
+                              u32 xor);
+
+        int (*write_reg32_slm)(PMF_STD_ARGS, u32 offset, u32 shift, u32 mask);
+        int (*write_reg16_slm)(PMF_STD_ARGS, u32 offset, u32 shift, u32 mask);
+        int (*write_reg8_slm)(PMF_STD_ARGS, u32 offset, u32 shift, u32 mask);
+
+        int (*mask_and_compare)(PMF_STD_ARGS, u32 len, const u8 *maskdata,
+                                const u8 *valuedata);
+
+        struct module *owner;
+};
+
+
+/*
+ * Drivers who expose platform functions register at init time, this
+ * causes the platform functions for that device node to be parsed in
+ * advance and associated with the device. The data structures are
+ * partially public so a driver can walk the list of platform functions
+ * and eventually inspect the flags
+ */
+struct pmf_device;
+
+struct pmf_function {
+        /* All functions for a given driver are linked */
+        struct list_head        link;
+
+        /* Function node & driver data */
+        struct device_node      *node;
+        void                    *driver_data;
+
+        /* For internal use by core */
+        struct pmf_device       *dev;
+
+        /* The name is the "xxx" in "platform-do-xxx", this is how
+         * platform functions are identified by this code. Some functions
+         * only operate for a given target, in which case the phandle is
+         * here (or 0 if the filter doesn't apply)
+         */
+        const char              *name;
+        u32                     phandle;
+
+        /* The flags for that function. You can have several functions
+         * with the same name and different flag
+         */
+        u32                     flags;
+
+        /* The actual tokenized function blob */
+        const void              *data;
+        unsigned int            length;
+
+        /* Interrupt clients */
+        struct list_head        irq_clients;
+
+        /* Refcounting */
+        struct kref             ref;
+};
+
+/*
+ * For platform functions that are interrupts, one can register
+ * irq_client structures. You canNOT use the same structure twice
+ * as it contains a link member. Also, the callback is called with
+ * a spinlock held, you must not call back into any of the pmf_* functions
+ * from within that callback
+ */
+struct pmf_irq_client {
+        void                    (*handler)(void *data);
+        void                    *data;
+        struct module           *owner;
+        struct list_head        link;
+};
+
+
+/*
+ * Register/Unregister a function-capable driver and its handlers
+ */
+extern int pmf_register_driver(struct device_node *np,
+                              struct pmf_handlers *handlers,
+                              void *driverdata);
+
+extern void pmf_unregister_driver(struct device_node *np);
+
+
+/*
+ * Register/Unregister interrupt clients
+ */
+extern int pmf_register_irq_client(struct device_node *np,
+                                   const char *name,
+                                   struct pmf_irq_client *client);
+
+extern void pmf_unregister_irq_client(struct device_node *np,
+                                      const char *name,
+                                      struct pmf_irq_client *client);
+
+/*
+ * Called by the handlers when an irq happens
+ */
+extern void pmf_do_irq(struct pmf_function *func);
+
+
+/*
+ * Low level call to platform functions.
+ *
+ * The phandle can filter on the target object for functions that have
+ * multiple targets, the flags allow you to restrict the call to a given
+ * combination of flags.
+ *
+ * The args array contains as many arguments as is required by the function,
+ * this is dependent on the function you are calling, unfortunately Apple
+ * mecanism provides no way to encode that so you have to get it right at
+ * the call site. Some functions require no args, in which case, you can
+ * pass NULL.
+ *
+ * You can also pass NULL to the name. This will match any function that has
+ * the appropriate combination of flags & phandle or you can pass 0 to the
+ * phandle to match any
+ */
+extern int pmf_do_functions(struct device_node *np, const char *name,
+                            u32 phandle, u32 flags, struct pmf_args *args);
+
+
+
+/*
+ * High level call to a platform function.
+ *
+ * This one looks for the platform-xxx first so you should call it to the
+ * actual target if any. It will fallback to platform-do-xxx if it can't
+ * find one. It will also exclusively target functions that have
+ * the "OnDemand" flag.
+ */
+
+extern int pmf_call_function(struct device_node *target, const char *name,
+                             struct pmf_args *args);
+
+
+/*
+ * For low latency interrupt usage, you can lookup for on-demand functions
+ * using the functions below
+ */
+
+extern struct pmf_function *pmf_find_function(struct device_node *target,
+                                              const char *name);
+
+extern struct pmf_function * pmf_get_function(struct pmf_function *func);
+extern void pmf_put_function(struct pmf_function *func);
+
+extern int pmf_call_one(struct pmf_function *func, struct pmf_args *args);
+
+
+/* Suspend/resume code called by via-pmu directly for now */
+extern void pmac_pfunc_base_suspend(void);
+extern void pmac_pfunc_base_resume(void);
+
+#endif /* __PMAC_PFUNC_H__ */