[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>

1 files changed, 292 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index a25e447..535c802 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -49,6 +49,7 @@
 #include <asm/prom.h>
 #include <asm/machdep.h>
 #include <asm/smu.h>
+#include <asm/pmac_pfunc.h>
 #include <asm/pmac_low_i2c.h>
 
 #ifdef DEBUG
@@ -1162,9 +1163,291 @@ int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
 }
 EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
 
+/* some quirks for platform function decoding */
+enum {
+	pmac_i2c_quirk_invmask = 0x00000001u,
+};
+
+static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
+					      int quirks))
+{
+	struct pmac_i2c_bus *bus;
+	struct device_node *np;
+	static struct whitelist_ent {
+		char *name;
+		char *compatible;
+		int quirks;
+	} whitelist[] = {
+		/* XXX Study device-tree's & apple drivers are get the quirks
+		 * right !
+		 */
+		{ "i2c-hwclock", NULL, pmac_i2c_quirk_invmask },
+		{ "i2c-cpu-voltage", NULL, 0},
+		{  "temp-monitor", NULL, 0 },
+		{  "supply-monitor", NULL, 0 },
+		{ NULL, NULL, 0 },
+	};
+
+	/* Only some devices need to have platform functions instanciated
+	 * here. For now, we have a table. Others, like 9554 i2c GPIOs used
+	 * on Xserve, if we ever do a driver for them, will use their own
+	 * platform function instance
+	 */
+	list_for_each_entry(bus, &pmac_i2c_busses, link) {
+		for (np = NULL;
+		     (np = of_get_next_child(bus->busnode, np)) != NULL;) {
+			struct whitelist_ent *p;
+			/* If multibus, check if device is on that bus */
+			if (bus->flags & pmac_i2c_multibus)
+				if (bus != pmac_i2c_find_bus(np))
+					continue;
+			for (p = whitelist; p->name != NULL; p++) {
+				if (strcmp(np->name, p->name))
+					continue;
+				if (p->compatible &&
+				    !device_is_compatible(np, p->compatible))
+					continue;
+				callback(np, p->quirks);
+				break;
+			}
+		}
+	}
+}
+
+#define MAX_I2C_DATA	64
+
+struct pmac_i2c_pf_inst
+{
+	struct pmac_i2c_bus	*bus;
+	u8			addr;
+	u8			buffer[MAX_I2C_DATA];
+	u8			scratch[MAX_I2C_DATA];
+	int			bytes;
+	int			quirks;
+};
+
+static void* pmac_i2c_do_begin(struct pmf_function *func, struct pmf_args *args)
+{
+	struct pmac_i2c_pf_inst *inst;
+	struct pmac_i2c_bus	*bus;
+
+	bus = pmac_i2c_find_bus(func->node);
+	if (bus == NULL) {
+		printk(KERN_ERR "low_i2c: Can't find bus for %s (pfunc)\n",
+		       func->node->full_name);
+		return NULL;
+	}
+	if (pmac_i2c_open(bus, 0)) {
+		printk(KERN_ERR "low_i2c: Can't open i2c bus for %s (pfunc)\n",
+		       func->node->full_name);
+		return NULL;
+	}
+
+	/* XXX might need GFP_ATOMIC when called during the suspend process,
+	 * but then, there are already lots of issues with suspending when
+	 * near OOM that need to be resolved, the allocator itself should
+	 * probably make GFP_NOIO implicit during suspend
+	 */
+	inst = kzalloc(sizeof(struct pmac_i2c_pf_inst), GFP_KERNEL);
+	if (inst == NULL) {
+		pmac_i2c_close(bus);
+		return NULL;
+	}
+	inst->bus = bus;
+	inst->addr = pmac_i2c_get_dev_addr(func->node);
+	inst->quirks = (int)(long)func->driver_data;
+	return inst;
+}
+
+static void pmac_i2c_do_end(struct pmf_function *func, void *instdata)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	if (inst == NULL)
+		return;
+	pmac_i2c_close(inst->bus);
+	if (inst)
+		kfree(inst);
+}
+
+static int pmac_i2c_do_read(PMF_STD_ARGS, u32 len)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	inst->bytes = len;
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 0, 0,
+			     inst->buffer, len);
+}
+
+static int pmac_i2c_do_write(PMF_STD_ARGS, u32 len, const u8 *data)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
+			     (u8 *)data, len);
+}
+
+/* This function is used to do the masking & OR'ing for the "rmw" type
+ * callbacks. Ze should apply the mask and OR in the values in the
+ * buffer before writing back. The problem is that it seems that
+ * various darwin drivers implement the mask/or differently, thus
+ * we need to check the quirks first
+ */
+static void pmac_i2c_do_apply_rmw(struct pmac_i2c_pf_inst *inst,
+				  u32 len, const u8 *mask, const u8 *val)
+{
+	int i;
+
+	if (inst->quirks & pmac_i2c_quirk_invmask) {
+		for (i = 0; i < len; i ++)
+			inst->scratch[i] = (inst->buffer[i] & mask[i]) | val[i];
+	} else {
+		for (i = 0; i < len; i ++)
+			inst->scratch[i] = (inst->buffer[i] & ~mask[i])
+				| (val[i] & mask[i]);
+	}
+}
+
+static int pmac_i2c_do_rmw(PMF_STD_ARGS, u32 masklen, u32 valuelen,
+			   u32 totallen, const u8 *maskdata,
+			   const u8 *valuedata)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	if (masklen > inst->bytes || valuelen > inst->bytes ||
+	    totallen > inst->bytes || valuelen > masklen)
+		return -EINVAL;
+
+	pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
+
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
+			     inst->scratch, totallen);
+}
+
+static int pmac_i2c_do_read_sub(PMF_STD_ARGS, u8 subaddr, u32 len)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	inst->bytes = len;
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 1, subaddr,
+			     inst->buffer, len);
+}
+
+static int pmac_i2c_do_write_sub(PMF_STD_ARGS, u8 subaddr, u32 len,
+				     const u8 *data)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
+			     subaddr, (u8 *)data, len);
+}
+
+static int pmac_i2c_do_set_mode(PMF_STD_ARGS, int mode)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	return pmac_i2c_setmode(inst->bus, mode);
+}
+
+static int pmac_i2c_do_rmw_sub(PMF_STD_ARGS, u8 subaddr, u32 masklen,
+			       u32 valuelen, u32 totallen, const u8 *maskdata,
+			       const u8 *valuedata)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+
+	if (masklen > inst->bytes || valuelen > inst->bytes ||
+	    totallen > inst->bytes || valuelen > masklen)
+		return -EINVAL;
+
+	pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
+
+	return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
+			     subaddr, inst->scratch, totallen);
+}
+
+static int pmac_i2c_do_mask_and_comp(PMF_STD_ARGS, u32 len,
+				     const u8 *maskdata,
+				     const u8 *valuedata)
+{
+	struct pmac_i2c_pf_inst *inst = instdata;
+	int i, match;
+
+	/* Get return value pointer, it's assumed to be a u32 */
+	if (!args || !args->count || !args->u[0].p)
+		return -EINVAL;
+
+	/* Check buffer */
+	if (len > inst->bytes)
+		return -EINVAL;
+
+	for (i = 0, match = 1; match && i < len; i ++)
+		if ((inst->buffer[i] & maskdata[i]) != valuedata[i])
+			match = 0;
+	*args->u[0].p = match;
+	return 0;
+}
+
+static int pmac_i2c_do_delay(PMF_STD_ARGS, u32 duration)
+{
+	msleep((duration + 999) / 1000);
+	return 0;
+}
+
+
+static struct pmf_handlers pmac_i2c_pfunc_handlers = {
+	.begin			= pmac_i2c_do_begin,
+	.end			= pmac_i2c_do_end,
+	.read_i2c		= pmac_i2c_do_read,
+	.write_i2c		= pmac_i2c_do_write,
+	.rmw_i2c		= pmac_i2c_do_rmw,
+	.read_i2c_sub		= pmac_i2c_do_read_sub,
+	.write_i2c_sub		= pmac_i2c_do_write_sub,
+	.rmw_i2c_sub		= pmac_i2c_do_rmw_sub,
+	.set_i2c_mode		= pmac_i2c_do_set_mode,
+	.mask_and_compare	= pmac_i2c_do_mask_and_comp,
+	.delay			= pmac_i2c_do_delay,
+};
+
+static void __init pmac_i2c_dev_create(struct device_node *np, int quirks)
+{
+	DBG("dev_create(%s)\n", np->full_name);
+
+	pmf_register_driver(np, &pmac_i2c_pfunc_handlers,
+			    (void *)(long)quirks);
+}
+
+static void __init pmac_i2c_dev_init(struct device_node *np, int quirks)
+{
+	DBG("dev_create(%s)\n", np->full_name);
+
+	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
+}
+
+static void pmac_i2c_dev_suspend(struct device_node *np, int quirks)
+{
+	DBG("dev_suspend(%s)\n", np->full_name);
+	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_SLEEP, NULL);
+}
+
+static void pmac_i2c_dev_resume(struct device_node *np, int quirks)
+{
+	DBG("dev_resume(%s)\n", np->full_name);
+	pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_WAKE, NULL);
+}
+
+void pmac_pfunc_i2c_suspend(void)
+{
+	pmac_i2c_devscan(pmac_i2c_dev_suspend);
+}
+
+void pmac_pfunc_i2c_resume(void)
+{
+	pmac_i2c_devscan(pmac_i2c_dev_resume);
+}
+
 /*
- * Initialize us: probe all i2c busses on the machine and instantiate
- * busses.
+ * Initialize us: probe all i2c busses on the machine, instantiate
+ * busses and platform functions as needed.
  */
 /* This is non-static as it might be called early by smp code */
 int __init pmac_i2c_init(void)
@@ -1187,6 +1470,10 @@ int __init pmac_i2c_init(void)
 	/* Probe SMU i2c busses */
 	smu_i2c_probe();
 #endif
+
+	/* Now add plaform functions for some known devices */
+	pmac_i2c_devscan(pmac_i2c_dev_create);
+
 	return 0;
 }
 arch_initcall(pmac_i2c_init);
@@ -1216,6 +1503,9 @@ static int __init pmac_i2c_create_platform_devices(void)
 		platform_device_add(bus->platform_dev);
 	}
 
+	/* Now call platform "init" functions */
+	pmac_i2c_devscan(pmac_i2c_dev_init);
+
 	return 0;
 }
 subsys_initcall(pmac_i2c_create_platform_devices);