+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Device State Control Registers driver
- *
- * Copyright (C) 2011 Texas Instruments Incorporated
- * Author: Mark Salter <msalter@redhat.com>
- */
-
-/*
- * 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);
-}
projects / linux-2.6-block.git / blobdiff