Initial import

1 files changed, 598 insertions, 0 deletions

diff --git a/arch/c6x/platforms/dscr.c b/arch/c6x/platforms/dscr.c
new file mode 100644
index 000000000..f848a65ee
--- /dev/null
+++ b/arch/c6x/platforms/dscr.c
@@ -0,0 +1,598 @@
+/*
+ *  Device State Control Registers driver
+ *
+ *  Copyright (C) 2011 Texas Instruments Incorporated
+ *  Author: Mark Salter <msalter@redhat.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+/*
+ * The Device State Control Registers (DSCR) provide SoC level control over
+ * a number of peripherals. Details vary considerably among the various SoC
+ * parts. In general, the DSCR block will provide one or more configuration
+ * registers often protected by a lock register. One or more key values must
+ * be written to a lock register in order to unlock the configuration register.
+ * The configuration register may be used to enable (and disable in some
+ * cases) SoC pin drivers, peripheral clock sources (internal or pin), etc.
+ * In some cases, a configuration register is write once or the individual
+ * bits are write once. That is, you may be able to enable a device, but
+ * will not be able to disable it.
+ *
+ * In addition to device configuration, the DSCR block may provide registers
+ * which are used to reset SoC peripherals, provide device ID information,
+ * provide MAC addresses, and other miscellaneous functions.
+ */
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <asm/soc.h>
+#include <asm/dscr.h>
+
+#define MAX_DEVSTATE_IDS   32
+#define MAX_DEVCTL_REGS     8
+#define MAX_DEVSTAT_REGS    8
+#define MAX_LOCKED_REGS     4
+#define MAX_SOC_EMACS       2
+
+struct rmii_reset_reg {
+	u32 reg;
+	u32 mask;
+};
+
+/*
+ * Some registerd may be locked. In order to write to these
+ * registers, the key value must first be written to the lockreg.
+ */
+struct locked_reg {
+	u32 reg;	/* offset from base */
+	u32 lockreg;	/* offset from base */
+	u32 key;	/* unlock key */
+};
+
+/*
+ * This describes a contiguous area of like control bits used to enable/disable
+ * SoC devices. Each controllable device is given an ID which is used by the
+ * individual device drivers to control the device state. These IDs start at
+ * zero and are assigned sequentially to the control bitfield ranges described
+ * by this structure.
+ */
+struct devstate_ctl_reg {
+	u32 reg;		/* register holding the control bits */
+	u8  start_id;		/* start id of this range */
+	u8  num_ids;		/* number of devices in this range */
+	u8  enable_only;	/* bits are write-once to enable only */
+	u8  enable;		/* value used to enable device */
+	u8  disable;		/* value used to disable device */
+	u8  shift;		/* starting (rightmost) bit in range */
+	u8  nbits;		/* number of bits per device */
+};
+
+
+/*
+ * This describes a region of status bits indicating the state of
+ * various devices. This is used internally to wait for status
+ * change completion when enabling/disabling a device. Status is
+ * optional and not all device controls will have a corresponding
+ * status.
+ */
+struct devstate_stat_reg {
+	u32 reg;		/* register holding the status bits */
+	u8  start_id;		/* start id of this range */
+	u8  num_ids;		/* number of devices in this range */
+	u8  enable;		/* value indicating enabled state */
+	u8  disable;		/* value indicating disabled state */
+	u8  shift;		/* starting (rightmost) bit in range */
+	u8  nbits;		/* number of bits per device */
+};
+
+struct devstate_info {
+	struct devstate_ctl_reg *ctl;
+	struct devstate_stat_reg *stat;
+};
+
+/* These are callbacks to SOC-specific code. */
+struct dscr_ops {
+	void (*init)(struct device_node *node);
+};
+
+struct dscr_regs {
+	spinlock_t		lock;
+	void __iomem		*base;
+	u32			kick_reg[2];
+	u32			kick_key[2];
+	struct locked_reg	locked[MAX_LOCKED_REGS];
+	struct devstate_info	devstate_info[MAX_DEVSTATE_IDS];
+	struct rmii_reset_reg   rmii_resets[MAX_SOC_EMACS];
+	struct devstate_ctl_reg devctl[MAX_DEVCTL_REGS];
+	struct devstate_stat_reg devstat[MAX_DEVSTAT_REGS];
+};
+
+static struct dscr_regs	dscr;
+
+static struct locked_reg *find_locked_reg(u32 reg)
+{
+	int i;
+
+	for (i = 0; i < MAX_LOCKED_REGS; i++)
+		if (dscr.locked[i].key && reg == dscr.locked[i].reg)
+			return &dscr.locked[i];
+	return NULL;
+}
+
+/*
+ * Write to a register with one lock
+ */
+static void dscr_write_locked1(u32 reg, u32 val,
+			       u32 lock, u32 key)
+{
+	void __iomem *reg_addr = dscr.base + reg;
+	void __iomem *lock_addr = dscr.base + lock;
+
+	/*
+	 * For some registers, the lock is relocked after a short number
+	 * of cycles. We have to put the lock write and register write in
+	 * the same fetch packet to meet this timing. The .align ensures
+	 * the two stw instructions are in the same fetch packet.
+	 */
+	asm volatile ("b	.s2	0f\n"
+		      "nop	5\n"
+		      "    .align 5\n"
+		      "0:\n"
+		      "stw	.D1T2	%3,*%2\n"
+		      "stw	.D1T2	%1,*%0\n"
+		      :
+		      : "a"(reg_addr), "b"(val), "a"(lock_addr), "b"(key)
+		);
+
+	/* in case the hw doesn't reset the lock */
+	soc_writel(0, lock_addr);
+}
+
+/*
+ * Write to a register protected by two lock registers
+ */
+static void dscr_write_locked2(u32 reg, u32 val,
+			       u32 lock0, u32 key0,
+			       u32 lock1, u32 key1)
+{
+	soc_writel(key0, dscr.base + lock0);
+	soc_writel(key1, dscr.base + lock1);
+	soc_writel(val, dscr.base + reg);
+	soc_writel(0, dscr.base + lock0);
+	soc_writel(0, dscr.base + lock1);
+}
+
+static void dscr_write(u32 reg, u32 val)
+{
+	struct locked_reg *lock;
+
+	lock = find_locked_reg(reg);
+	if (lock)
+		dscr_write_locked1(reg, val, lock->lockreg, lock->key);
+	else if (dscr.kick_key[0])
+		dscr_write_locked2(reg, val, dscr.kick_reg[0], dscr.kick_key[0],
+				   dscr.kick_reg[1], dscr.kick_key[1]);
+	else
+		soc_writel(val, dscr.base + reg);
+}
+
+
+/*
+ * Drivers can use this interface to enable/disable SoC IP blocks.
+ */
+void dscr_set_devstate(int id, enum dscr_devstate_t state)
+{
+	struct devstate_ctl_reg *ctl;
+	struct devstate_stat_reg *stat;
+	struct devstate_info *info;
+	u32 ctl_val, val;
+	int ctl_shift, ctl_mask;
+	unsigned long flags;
+
+	if (!dscr.base)
+		return;
+
+	if (id < 0 || id >= MAX_DEVSTATE_IDS)
+		return;
+
+	info = &dscr.devstate_info[id];
+	ctl = info->ctl;
+	stat = info->stat;
+
+	if (ctl == NULL)
+		return;
+
+	ctl_shift = ctl->shift + ctl->nbits * (id - ctl->start_id);
+	ctl_mask = ((1 << ctl->nbits) - 1) << ctl_shift;
+
+	switch (state) {
+	case DSCR_DEVSTATE_ENABLED:
+		ctl_val = ctl->enable << ctl_shift;
+		break;
+	case DSCR_DEVSTATE_DISABLED:
+		if (ctl->enable_only)
+			return;
+		ctl_val = ctl->disable << ctl_shift;
+		break;
+	default:
+		return;
+	}
+
+	spin_lock_irqsave(&dscr.lock, flags);
+
+	val = soc_readl(dscr.base + ctl->reg);
+	val &= ~ctl_mask;
+	val |= ctl_val;
+
+	dscr_write(ctl->reg, val);
+
+	spin_unlock_irqrestore(&dscr.lock, flags);
+
+	if (!stat)
+		return;
+
+	ctl_shift = stat->shift + stat->nbits * (id - stat->start_id);
+
+	if (state == DSCR_DEVSTATE_ENABLED)
+		ctl_val = stat->enable;
+	else
+		ctl_val = stat->disable;
+
+	do {
+		val = soc_readl(dscr.base + stat->reg);
+		val >>= ctl_shift;
+		val &= ((1 << stat->nbits) - 1);
+	} while (val != ctl_val);
+}
+EXPORT_SYMBOL(dscr_set_devstate);
+
+/*
+ * Drivers can use this to reset RMII module.
+ */
+void dscr_rmii_reset(int id, int assert)
+{
+	struct rmii_reset_reg *r;
+	unsigned long flags;
+	u32 val;
+
+	if (id < 0 || id >= MAX_SOC_EMACS)
+		return;
+
+	r = &dscr.rmii_resets[id];
+	if (r->mask == 0)
+		return;
+
+	spin_lock_irqsave(&dscr.lock, flags);
+
+	val = soc_readl(dscr.base + r->reg);
+	if (assert)
+		dscr_write(r->reg, val | r->mask);
+	else
+		dscr_write(r->reg, val & ~(r->mask));
+
+	spin_unlock_irqrestore(&dscr.lock, flags);
+}
+EXPORT_SYMBOL(dscr_rmii_reset);
+
+static void __init dscr_parse_devstat(struct device_node *node,
+				      void __iomem *base)
+{
+	u32 val;
+	int err;
+
+	err = of_property_read_u32_array(node, "ti,dscr-devstat", &val, 1);
+	if (!err)
+		c6x_devstat = soc_readl(base + val);
+	printk(KERN_INFO "DEVSTAT: %08x\n", c6x_devstat);
+}
+
+static void __init dscr_parse_silicon_rev(struct device_node *node,
+					 void __iomem *base)
+{
+	u32 vals[3];
+	int err;
+
+	err = of_property_read_u32_array(node, "ti,dscr-silicon-rev", vals, 3);
+	if (!err) {
+		c6x_silicon_rev = soc_readl(base + vals[0]);
+		c6x_silicon_rev >>= vals[1];
+		c6x_silicon_rev &= vals[2];
+	}
+}
+
+/*
+ * Some SoCs will have a pair of fuse registers which hold
+ * an ethernet MAC address. The "ti,dscr-mac-fuse-regs"
+ * property is a mapping from fuse register bytes to MAC
+ * address bytes. The expected format is:
+ *
+ *	ti,dscr-mac-fuse-regs = <reg0 b3 b2 b1 b0
+ *				 reg1 b3 b2 b1 b0>
+ *
+ * reg0 and reg1 are the offsets of the two fuse registers.
+ * b3-b0 positionally represent bytes within the fuse register.
+ * b3 is the most significant byte and b0 is the least.
+ * Allowable values for b3-b0 are:
+ *
+ *	  0 = fuse register byte not used in MAC address
+ *      1-6 = index+1 into c6x_fuse_mac[]
+ */
+static void __init dscr_parse_mac_fuse(struct device_node *node,
+				       void __iomem *base)
+{
+	u32 vals[10], fuse;
+	int f, i, j, err;
+
+	err = of_property_read_u32_array(node, "ti,dscr-mac-fuse-regs",
+					 vals, 10);
+	if (err)
+		return;
+
+	for (f = 0; f < 2; f++) {
+		fuse = soc_readl(base + vals[f * 5]);
+		for (j = (f * 5) + 1, i = 24; i >= 0; i -= 8, j++)
+			if (vals[j] && vals[j] <= 6)
+				c6x_fuse_mac[vals[j] - 1] = fuse >> i;
+	}
+}
+
+static void __init dscr_parse_rmii_resets(struct device_node *node,
+					  void __iomem *base)
+{
+	const __be32 *p;
+	int i, size;
+
+	/* look for RMII reset registers */
+	p = of_get_property(node, "ti,dscr-rmii-resets", &size);
+	if (p) {
+		/* parse all the reg/mask pairs we can handle */
+		size /= (sizeof(*p) * 2);
+		if (size > MAX_SOC_EMACS)
+			size = MAX_SOC_EMACS;
+
+		for (i = 0; i < size; i++) {
+			dscr.rmii_resets[i].reg = be32_to_cpup(p++);
+			dscr.rmii_resets[i].mask = be32_to_cpup(p++);
+		}
+	}
+}
+
+
+static void __init dscr_parse_privperm(struct device_node *node,
+				       void __iomem *base)
+{
+	u32 vals[2];
+	int err;
+
+	err = of_property_read_u32_array(node, "ti,dscr-privperm", vals, 2);
+	if (err)
+		return;
+	dscr_write(vals[0], vals[1]);
+}
+
+/*
+ * SoCs may have "locked" DSCR registers which can only be written
+ * to only after writing a key value to a lock registers. These
+ * regisers can be described with the "ti,dscr-locked-regs" property.
+ * This property provides a list of register descriptions with each
+ * description consisting of three values.
+ *
+ *	ti,dscr-locked-regs = <reg0 lockreg0 key0
+ *                               ...
+ *                             regN lockregN keyN>;
+ *
+ * reg is the offset of the locked register
+ * lockreg is the offset of the lock register
+ * key is the unlock key written to lockreg
+ *
+ */
+static void __init dscr_parse_locked_regs(struct device_node *node,
+					  void __iomem *base)
+{
+	struct locked_reg *r;
+	const __be32 *p;
+	int i, size;
+
+	p = of_get_property(node, "ti,dscr-locked-regs", &size);
+	if (p) {
+		/* parse all the register descriptions we can handle */
+		size /= (sizeof(*p) * 3);
+		if (size > MAX_LOCKED_REGS)
+			size = MAX_LOCKED_REGS;
+
+		for (i = 0; i < size; i++) {
+			r = &dscr.locked[i];
+
+			r->reg = be32_to_cpup(p++);
+			r->lockreg = be32_to_cpup(p++);
+			r->key = be32_to_cpup(p++);
+		}
+	}
+}
+
+/*
+ * SoCs may have DSCR registers which are only write enabled after
+ * writing specific key values to two registers. The two key registers
+ * and the key values can be parsed from a "ti,dscr-kick-regs"
+ * propety with the following layout:
+ *
+ *	ti,dscr-kick-regs = <kickreg0 key0 kickreg1 key1>
+ *
+ * kickreg is the offset of the "kick" register
+ * key is the value which unlocks writing for protected regs
+ */
+static void __init dscr_parse_kick_regs(struct device_node *node,
+					void __iomem *base)
+{
+	u32 vals[4];
+	int err;
+
+	err = of_property_read_u32_array(node, "ti,dscr-kick-regs", vals, 4);
+	if (!err) {
+		dscr.kick_reg[0] = vals[0];
+		dscr.kick_key[0] = vals[1];
+		dscr.kick_reg[1] = vals[2];
+		dscr.kick_key[1] = vals[3];
+	}
+}
+
+
+/*
+ * SoCs may provide controls to enable/disable individual IP blocks. These
+ * controls in the DSCR usually control pin drivers but also may control
+ * clocking and or resets. The device tree is used to describe the bitfields
+ * in registers used to control device state. The number of bits and their
+ * values may vary even within the same register.
+ *
+ * The layout of these bitfields is described by the ti,dscr-devstate-ctl-regs
+ * property. This property is a list where each element describes a contiguous
+ * range of control fields with like properties. Each element of the list
+ * consists of 7 cells with the following values:
+ *
+ *   start_id num_ids reg enable disable start_bit nbits
+ *
+ * start_id is device id for the first device control in the range
+ * num_ids is the number of device controls in the range
+ * reg is the offset of the register holding the control bits
+ * enable is the value to enable a device
+ * disable is the value to disable a device (0xffffffff if cannot disable)
+ * start_bit is the bit number of the first bit in the range
+ * nbits is the number of bits per device control
+ */
+static void __init dscr_parse_devstate_ctl_regs(struct device_node *node,
+						void __iomem *base)
+{
+	struct devstate_ctl_reg *r;
+	const __be32 *p;
+	int i, j, size;
+
+	p = of_get_property(node, "ti,dscr-devstate-ctl-regs", &size);
+	if (p) {
+		/* parse all the ranges we can handle */
+		size /= (sizeof(*p) * 7);
+		if (size > MAX_DEVCTL_REGS)
+			size = MAX_DEVCTL_REGS;
+
+		for (i = 0; i < size; i++) {
+			r = &dscr.devctl[i];
+
+			r->start_id = be32_to_cpup(p++);
+			r->num_ids = be32_to_cpup(p++);
+			r->reg = be32_to_cpup(p++);
+			r->enable = be32_to_cpup(p++);
+			r->disable = be32_to_cpup(p++);
+			if (r->disable == 0xffffffff)
+				r->enable_only = 1;
+			r->shift = be32_to_cpup(p++);
+			r->nbits = be32_to_cpup(p++);
+
+			for (j = r->start_id;
+			     j < (r->start_id + r->num_ids);
+			     j++)
+				dscr.devstate_info[j].ctl = r;
+		}
+	}
+}
+
+/*
+ * SoCs may provide status registers indicating the state (enabled/disabled) of
+ * devices on the SoC. The device tree is used to describe the bitfields in
+ * registers used to provide device status. The number of bits and their
+ * values used to provide status may vary even within the same register.
+ *
+ * The layout of these bitfields is described by the ti,dscr-devstate-stat-regs
+ * property. This property is a list where each element describes a contiguous
+ * range of status fields with like properties. Each element of the list
+ * consists of 7 cells with the following values:
+ *
+ *   start_id num_ids reg enable disable start_bit nbits
+ *
+ * start_id is device id for the first device status in the range
+ * num_ids is the number of devices covered by the range
+ * reg is the offset of the register holding the status bits
+ * enable is the value indicating device is enabled
+ * disable is the value indicating device is disabled
+ * start_bit is the bit number of the first bit in the range
+ * nbits is the number of bits per device status
+ */
+static void __init dscr_parse_devstate_stat_regs(struct device_node *node,
+						 void __iomem *base)
+{
+	struct devstate_stat_reg *r;
+	const __be32 *p;
+	int i, j, size;
+
+	p = of_get_property(node, "ti,dscr-devstate-stat-regs", &size);
+	if (p) {
+		/* parse all the ranges we can handle */
+		size /= (sizeof(*p) * 7);
+		if (size > MAX_DEVSTAT_REGS)
+			size = MAX_DEVSTAT_REGS;
+
+		for (i = 0; i < size; i++) {
+			r = &dscr.devstat[i];
+
+			r->start_id = be32_to_cpup(p++);
+			r->num_ids = be32_to_cpup(p++);
+			r->reg = be32_to_cpup(p++);
+			r->enable = be32_to_cpup(p++);
+			r->disable = be32_to_cpup(p++);
+			r->shift = be32_to_cpup(p++);
+			r->nbits = be32_to_cpup(p++);
+
+			for (j = r->start_id;
+			     j < (r->start_id + r->num_ids);
+			     j++)
+				dscr.devstate_info[j].stat = r;
+		}
+	}
+}
+
+static struct of_device_id dscr_ids[] __initdata = {
+	{ .compatible = "ti,c64x+dscr" },
+	{}
+};
+
+/*
+ * Probe for DSCR area.
+ *
+ * This has to be done early on in case timer or interrupt controller
+ * needs something. e.g. On C6455 SoC, timer must be enabled through
+ * DSCR before it is functional.
+ */
+void __init dscr_probe(void)
+{
+	struct device_node *node;
+	void __iomem *base;
+
+	spin_lock_init(&dscr.lock);
+
+	node = of_find_matching_node(NULL, dscr_ids);
+	if (!node)
+		return;
+
+	base = of_iomap(node, 0);
+	if (!base) {
+		of_node_put(node);
+		return;
+	}
+
+	dscr.base = base;
+
+	dscr_parse_devstat(node, base);
+	dscr_parse_silicon_rev(node, base);
+	dscr_parse_mac_fuse(node, base);
+	dscr_parse_rmii_resets(node, base);
+	dscr_parse_locked_regs(node, base);
+	dscr_parse_kick_regs(node, base);
+	dscr_parse_devstate_ctl_regs(node, base);
+	dscr_parse_devstate_stat_regs(node, base);
+	dscr_parse_privperm(node, base);
+}