xref: /openbmc/linux/drivers/soc/fsl/qe/qe.c (revision 4c3e565c)

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2006-2010 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Authors: 	Shlomi Gridish <gridish@freescale.com>
 * 		Li Yang <leoli@freescale.com>
 * Based on cpm2_common.c from Dan Malek (dmalek@jlc.net)
 *
 * Description:
 * General Purpose functions for the global management of the
 * QUICC Engine (QE).
 */
#include <linux/bitmap.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/iopoll.h>
#include <linux/crc32.h>
#include <linux/mod_devicetable.h>
#include <linux/of_platform.h>
#include <soc/fsl/qe/immap_qe.h>
#include <soc/fsl/qe/qe.h>

static void qe_snums_init(void);
static int qe_sdma_init(void);

static DEFINE_SPINLOCK(qe_lock);
DEFINE_SPINLOCK(cmxgcr_lock);
EXPORT_SYMBOL(cmxgcr_lock);

/* We allocate this here because it is used almost exclusively for
 * the communication processor devices.
 */
struct qe_immap __iomem *qe_immr;
EXPORT_SYMBOL(qe_immr);

static u8 snums[QE_NUM_OF_SNUM];	/* Dynamically allocated SNUMs */
static DECLARE_BITMAP(snum_state, QE_NUM_OF_SNUM);
static unsigned int qe_num_of_snum;

static phys_addr_t qebase = -1;

static struct device_node *qe_get_device_node(void)
{
	struct device_node *qe;

	/*
	 * Newer device trees have an "fsl,qe" compatible property for the QE
	 * node, but we still need to support older device trees.
	 */
	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (qe)
		return qe;
	return of_find_node_by_type(NULL, "qe");
}

static phys_addr_t get_qe_base(void)
{
	struct device_node *qe;
	int ret;
	struct resource res;

	if (qebase != -1)
		return qebase;

	qe = qe_get_device_node();
	if (!qe)
		return qebase;

	ret = of_address_to_resource(qe, 0, &res);
	if (!ret)
		qebase = res.start;
	of_node_put(qe);

	return qebase;
}

void qe_reset(void)
{
	if (qe_immr == NULL)
		qe_immr = ioremap(get_qe_base(), QE_IMMAP_SIZE);

	qe_snums_init();

	qe_issue_cmd(QE_RESET, QE_CR_SUBBLOCK_INVALID,
		     QE_CR_PROTOCOL_UNSPECIFIED, 0);

	/* Reclaim the MURAM memory for our use. */
	qe_muram_init();

	if (qe_sdma_init())
		panic("sdma init failed!");
}

int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input)
{
	unsigned long flags;
	u8 mcn_shift = 0, dev_shift = 0;
	u32 val;
	int ret;

	spin_lock_irqsave(&qe_lock, flags);
	if (cmd == QE_RESET) {
		qe_iowrite32be((u32)(cmd | QE_CR_FLG), &qe_immr->cp.cecr);
	} else {
		if (cmd == QE_ASSIGN_PAGE) {
			/* Here device is the SNUM, not sub-block */
			dev_shift = QE_CR_SNUM_SHIFT;
		} else if (cmd == QE_ASSIGN_RISC) {
			/* Here device is the SNUM, and mcnProtocol is
			 * e_QeCmdRiscAssignment value */
			dev_shift = QE_CR_SNUM_SHIFT;
			mcn_shift = QE_CR_MCN_RISC_ASSIGN_SHIFT;
		} else {
			if (device == QE_CR_SUBBLOCK_USB)
				mcn_shift = QE_CR_MCN_USB_SHIFT;
			else
				mcn_shift = QE_CR_MCN_NORMAL_SHIFT;
		}

		qe_iowrite32be(cmd_input, &qe_immr->cp.cecdr);
		qe_iowrite32be((cmd | QE_CR_FLG | ((u32)device << dev_shift) | (u32)mcn_protocol << mcn_shift),
			       &qe_immr->cp.cecr);
	}

	/* wait for the QE_CR_FLG to clear */
	ret = readx_poll_timeout_atomic(qe_ioread32be, &qe_immr->cp.cecr, val,
					(val & QE_CR_FLG) == 0, 0, 100);
	/* On timeout, ret is -ETIMEDOUT, otherwise it will be 0. */
	spin_unlock_irqrestore(&qe_lock, flags);

	return ret == 0;
}
EXPORT_SYMBOL(qe_issue_cmd);

/* Set a baud rate generator. This needs lots of work. There are
 * 16 BRGs, which can be connected to the QE channels or output
 * as clocks. The BRGs are in two different block of internal
 * memory mapped space.
 * The BRG clock is the QE clock divided by 2.
 * It was set up long ago during the initial boot phase and is
 * is given to us.
 * Baud rate clocks are zero-based in the driver code (as that maps
 * to port numbers). Documentation uses 1-based numbering.
 */
static unsigned int brg_clk = 0;

#define CLK_GRAN	(1000)
#define CLK_GRAN_LIMIT	(5)

unsigned int qe_get_brg_clk(void)
{
	struct device_node *qe;
	u32 brg;
	unsigned int mod;

	if (brg_clk)
		return brg_clk;

	qe = qe_get_device_node();
	if (!qe)
		return brg_clk;

	if (!of_property_read_u32(qe, "brg-frequency", &brg))
		brg_clk = brg;

	of_node_put(qe);

	/* round this if near to a multiple of CLK_GRAN */
	mod = brg_clk % CLK_GRAN;
	if (mod) {
		if (mod < CLK_GRAN_LIMIT)
			brg_clk -= mod;
		else if (mod > (CLK_GRAN - CLK_GRAN_LIMIT))
			brg_clk += CLK_GRAN - mod;
	}

	return brg_clk;
}
EXPORT_SYMBOL(qe_get_brg_clk);

#define PVR_VER_836x	0x8083
#define PVR_VER_832x	0x8084

static bool qe_general4_errata(void)
{
#ifdef CONFIG_PPC32
	return pvr_version_is(PVR_VER_836x) || pvr_version_is(PVR_VER_832x);
#endif
	return false;
}

/* Program the BRG to the given sampling rate and multiplier
 *
 * @brg: the BRG, QE_BRG1 - QE_BRG16
 * @rate: the desired sampling rate
 * @multiplier: corresponds to the value programmed in GUMR_L[RDCR] or
 * GUMR_L[TDCR].  E.g., if this BRG is the RX clock, and GUMR_L[RDCR]=01,
 * then 'multiplier' should be 8.
 */
int qe_setbrg(enum qe_clock brg, unsigned int rate, unsigned int multiplier)
{
	u32 divisor, tempval;
	u32 div16 = 0;

	if ((brg < QE_BRG1) || (brg > QE_BRG16))
		return -EINVAL;

	divisor = qe_get_brg_clk() / (rate * multiplier);

	if (divisor > QE_BRGC_DIVISOR_MAX + 1) {
		div16 = QE_BRGC_DIV16;
		divisor /= 16;
	}

	/* Errata QE_General4, which affects some MPC832x and MPC836x SOCs, says
	   that the BRG divisor must be even if you're not using divide-by-16
	   mode. */
	if (qe_general4_errata())
		if (!div16 && (divisor & 1) && (divisor > 3))
			divisor++;

	tempval = ((divisor - 1) << QE_BRGC_DIVISOR_SHIFT) |
		QE_BRGC_ENABLE | div16;

	qe_iowrite32be(tempval, &qe_immr->brg.brgc[brg - QE_BRG1]);

	return 0;
}
EXPORT_SYMBOL(qe_setbrg);

/* Convert a string to a QE clock source enum
 *
 * This function takes a string, typically from a property in the device
 * tree, and returns the corresponding "enum qe_clock" value.
*/
enum qe_clock qe_clock_source(const char *source)
{
	unsigned int i;

	if (strcasecmp(source, "none") == 0)
		return QE_CLK_NONE;

	if (strcmp(source, "tsync_pin") == 0)
		return QE_TSYNC_PIN;

	if (strcmp(source, "rsync_pin") == 0)
		return QE_RSYNC_PIN;

	if (strncasecmp(source, "brg", 3) == 0) {
		i = simple_strtoul(source + 3, NULL, 10);
		if ((i >= 1) && (i <= 16))
			return (QE_BRG1 - 1) + i;
		else
			return QE_CLK_DUMMY;
	}

	if (strncasecmp(source, "clk", 3) == 0) {
		i = simple_strtoul(source + 3, NULL, 10);
		if ((i >= 1) && (i <= 24))
			return (QE_CLK1 - 1) + i;
		else
			return QE_CLK_DUMMY;
	}

	return QE_CLK_DUMMY;
}
EXPORT_SYMBOL(qe_clock_source);

/* Initialize SNUMs (thread serial numbers) according to
 * QE Module Control chapter, SNUM table
 */
static void qe_snums_init(void)
{
	static const u8 snum_init_76[] = {
		0x04, 0x05, 0x0C, 0x0D, 0x14, 0x15, 0x1C, 0x1D,
		0x24, 0x25, 0x2C, 0x2D, 0x34, 0x35, 0x88, 0x89,
		0x98, 0x99, 0xA8, 0xA9, 0xB8, 0xB9, 0xC8, 0xC9,
		0xD8, 0xD9, 0xE8, 0xE9, 0x44, 0x45, 0x4C, 0x4D,
		0x54, 0x55, 0x5C, 0x5D, 0x64, 0x65, 0x6C, 0x6D,
		0x74, 0x75, 0x7C, 0x7D, 0x84, 0x85, 0x8C, 0x8D,
		0x94, 0x95, 0x9C, 0x9D, 0xA4, 0xA5, 0xAC, 0xAD,
		0xB4, 0xB5, 0xBC, 0xBD, 0xC4, 0xC5, 0xCC, 0xCD,
		0xD4, 0xD5, 0xDC, 0xDD, 0xE4, 0xE5, 0xEC, 0xED,
		0xF4, 0xF5, 0xFC, 0xFD,
	};
	static const u8 snum_init_46[] = {
		0x04, 0x05, 0x0C, 0x0D, 0x14, 0x15, 0x1C, 0x1D,
		0x24, 0x25, 0x2C, 0x2D, 0x34, 0x35, 0x88, 0x89,
		0x98, 0x99, 0xA8, 0xA9, 0xB8, 0xB9, 0xC8, 0xC9,
		0xD8, 0xD9, 0xE8, 0xE9, 0x08, 0x09, 0x18, 0x19,
		0x28, 0x29, 0x38, 0x39, 0x48, 0x49, 0x58, 0x59,
		0x68, 0x69, 0x78, 0x79, 0x80, 0x81,
	};
	struct device_node *qe;
	const u8 *snum_init;
	int i;

	bitmap_zero(snum_state, QE_NUM_OF_SNUM);
	qe_num_of_snum = 28; /* The default number of snum for threads is 28 */
	qe = qe_get_device_node();
	if (qe) {
		i = of_property_read_variable_u8_array(qe, "fsl,qe-snums",
						       snums, 1, QE_NUM_OF_SNUM);
		if (i > 0) {
			of_node_put(qe);
			qe_num_of_snum = i;
			return;
		}
		/*
		 * Fall back to legacy binding of using the value of
		 * fsl,qe-num-snums to choose one of the static arrays
		 * above.
		 */
		of_property_read_u32(qe, "fsl,qe-num-snums", &qe_num_of_snum);
		of_node_put(qe);
	}

	if (qe_num_of_snum == 76) {
		snum_init = snum_init_76;
	} else if (qe_num_of_snum == 28 || qe_num_of_snum == 46) {
		snum_init = snum_init_46;
	} else {
		pr_err("QE: unsupported value of fsl,qe-num-snums: %u\n", qe_num_of_snum);
		return;
	}
	memcpy(snums, snum_init, qe_num_of_snum);
}

int qe_get_snum(void)
{
	unsigned long flags;
	int snum = -EBUSY;
	int i;

	spin_lock_irqsave(&qe_lock, flags);
	i = find_first_zero_bit(snum_state, qe_num_of_snum);
	if (i < qe_num_of_snum) {
		set_bit(i, snum_state);
		snum = snums[i];
	}
	spin_unlock_irqrestore(&qe_lock, flags);

	return snum;
}
EXPORT_SYMBOL(qe_get_snum);

void qe_put_snum(u8 snum)
{
	const u8 *p = memchr(snums, snum, qe_num_of_snum);

	if (p)
		clear_bit(p - snums, snum_state);
}
EXPORT_SYMBOL(qe_put_snum);

static int qe_sdma_init(void)
{
	struct sdma __iomem *sdma = &qe_immr->sdma;
	static s32 sdma_buf_offset = -ENOMEM;

	if (!sdma)
		return -ENODEV;

	/* allocate 2 internal temporary buffers (512 bytes size each) for
	 * the SDMA */
	if (sdma_buf_offset < 0) {
		sdma_buf_offset = qe_muram_alloc(512 * 2, 4096);
		if (sdma_buf_offset < 0)
			return -ENOMEM;
	}

	qe_iowrite32be((u32)sdma_buf_offset & QE_SDEBCR_BA_MASK,
		       &sdma->sdebcr);
	qe_iowrite32be((QE_SDMR_GLB_1_MSK | (0x1 << QE_SDMR_CEN_SHIFT)),
		       &sdma->sdmr);

	return 0;
}

/* The maximum number of RISCs we support */
#define MAX_QE_RISC     4

/* Firmware information stored here for qe_get_firmware_info() */
static struct qe_firmware_info qe_firmware_info;

/*
 * Set to 1 if QE firmware has been uploaded, and therefore
 * qe_firmware_info contains valid data.
 */
static int qe_firmware_uploaded;

/*
 * Upload a QE microcode
 *
 * This function is a worker function for qe_upload_firmware().  It does
 * the actual uploading of the microcode.
 */
static void qe_upload_microcode(const void *base,
	const struct qe_microcode *ucode)
{
	const __be32 *code = base + be32_to_cpu(ucode->code_offset);
	unsigned int i;

	if (ucode->major || ucode->minor || ucode->revision)
		printk(KERN_INFO "qe-firmware: "
			"uploading microcode '%s' version %u.%u.%u\n",
			ucode->id, ucode->major, ucode->minor, ucode->revision);
	else
		printk(KERN_INFO "qe-firmware: "
			"uploading microcode '%s'\n", ucode->id);

	/* Use auto-increment */
	qe_iowrite32be(be32_to_cpu(ucode->iram_offset) | QE_IRAM_IADD_AIE | QE_IRAM_IADD_BADDR,
		       &qe_immr->iram.iadd);

	for (i = 0; i < be32_to_cpu(ucode->count); i++)
		qe_iowrite32be(be32_to_cpu(code[i]), &qe_immr->iram.idata);

	/* Set I-RAM Ready Register */
	qe_iowrite32be(be32_to_cpu(QE_IRAM_READY), &qe_immr->iram.iready);
}

/*
 * Upload a microcode to the I-RAM at a specific address.
 *
 * See Documentation/powerpc/qe_firmware.rst for information on QE microcode
 * uploading.
 *
 * Currently, only version 1 is supported, so the 'version' field must be
 * set to 1.
 *
 * The SOC model and revision are not validated, they are only displayed for
 * informational purposes.
 *
 * 'calc_size' is the calculated size, in bytes, of the firmware structure and
 * all of the microcode structures, minus the CRC.
 *
 * 'length' is the size that the structure says it is, including the CRC.
 */
int qe_upload_firmware(const struct qe_firmware *firmware)
{
	unsigned int i;
	unsigned int j;
	u32 crc;
	size_t calc_size = sizeof(struct qe_firmware);
	size_t length;
	const struct qe_header *hdr;

	if (!firmware) {
		printk(KERN_ERR "qe-firmware: invalid pointer\n");
		return -EINVAL;
	}

	hdr = &firmware->header;
	length = be32_to_cpu(hdr->length);

	/* Check the magic */
	if ((hdr->magic[0] != 'Q') || (hdr->magic[1] != 'E') ||
	    (hdr->magic[2] != 'F')) {
		printk(KERN_ERR "qe-firmware: not a microcode\n");
		return -EPERM;
	}

	/* Check the version */
	if (hdr->version != 1) {
		printk(KERN_ERR "qe-firmware: unsupported version\n");
		return -EPERM;
	}

	/* Validate some of the fields */
	if ((firmware->count < 1) || (firmware->count > MAX_QE_RISC)) {
		printk(KERN_ERR "qe-firmware: invalid data\n");
		return -EINVAL;
	}

	/* Validate the length and check if there's a CRC */
	calc_size += (firmware->count - 1) * sizeof(struct qe_microcode);

	for (i = 0; i < firmware->count; i++)
		/*
		 * For situations where the second RISC uses the same microcode
		 * as the first, the 'code_offset' and 'count' fields will be
		 * zero, so it's okay to add those.
		 */
		calc_size += sizeof(__be32) *
			be32_to_cpu(firmware->microcode[i].count);

	/* Validate the length */
	if (length != calc_size + sizeof(__be32)) {
		printk(KERN_ERR "qe-firmware: invalid length\n");
		return -EPERM;
	}

	/* Validate the CRC */
	crc = be32_to_cpu(*(__be32 *)((void *)firmware + calc_size));
	if (crc != crc32(0, firmware, calc_size)) {
		printk(KERN_ERR "qe-firmware: firmware CRC is invalid\n");
		return -EIO;
	}

	/*
	 * If the microcode calls for it, split the I-RAM.
	 */
	if (!firmware->split)
		qe_setbits_be16(&qe_immr->cp.cercr, QE_CP_CERCR_CIR);

	if (firmware->soc.model)
		printk(KERN_INFO
			"qe-firmware: firmware '%s' for %u V%u.%u\n",
			firmware->id, be16_to_cpu(firmware->soc.model),
			firmware->soc.major, firmware->soc.minor);
	else
		printk(KERN_INFO "qe-firmware: firmware '%s'\n",
			firmware->id);

	/*
	 * The QE only supports one microcode per RISC, so clear out all the
	 * saved microcode information and put in the new.
	 */
	memset(&qe_firmware_info, 0, sizeof(qe_firmware_info));
	strlcpy(qe_firmware_info.id, firmware->id, sizeof(qe_firmware_info.id));
	qe_firmware_info.extended_modes = firmware->extended_modes;
	memcpy(qe_firmware_info.vtraps, firmware->vtraps,
		sizeof(firmware->vtraps));

	/* Loop through each microcode. */
	for (i = 0; i < firmware->count; i++) {
		const struct qe_microcode *ucode = &firmware->microcode[i];

		/* Upload a microcode if it's present */
		if (ucode->code_offset)
			qe_upload_microcode(firmware, ucode);

		/* Program the traps for this processor */
		for (j = 0; j < 16; j++) {
			u32 trap = be32_to_cpu(ucode->traps[j]);

			if (trap)
				qe_iowrite32be(trap,
					       &qe_immr->rsp[i].tibcr[j]);
		}

		/* Enable traps */
		qe_iowrite32be(be32_to_cpu(ucode->eccr),
			       &qe_immr->rsp[i].eccr);
	}

	qe_firmware_uploaded = 1;

	return 0;
}
EXPORT_SYMBOL(qe_upload_firmware);

/*
 * Get info on the currently-loaded firmware
 *
 * This function also checks the device tree to see if the boot loader has
 * uploaded a firmware already.
 */
struct qe_firmware_info *qe_get_firmware_info(void)
{
	static int initialized;
	struct device_node *qe;
	struct device_node *fw = NULL;
	const char *sprop;

	/*
	 * If we haven't checked yet, and a driver hasn't uploaded a firmware
	 * yet, then check the device tree for information.
	 */
	if (qe_firmware_uploaded)
		return &qe_firmware_info;

	if (initialized)
		return NULL;

	initialized = 1;

	qe = qe_get_device_node();
	if (!qe)
		return NULL;

	/* Find the 'firmware' child node */
	fw = of_get_child_by_name(qe, "firmware");
	of_node_put(qe);

	/* Did we find the 'firmware' node? */
	if (!fw)
		return NULL;

	qe_firmware_uploaded = 1;

	/* Copy the data into qe_firmware_info*/
	sprop = of_get_property(fw, "id", NULL);
	if (sprop)
		strlcpy(qe_firmware_info.id, sprop,
			sizeof(qe_firmware_info.id));

	of_property_read_u64(fw, "extended-modes",
			     &qe_firmware_info.extended_modes);

	of_property_read_u32_array(fw, "virtual-traps", qe_firmware_info.vtraps,
				   ARRAY_SIZE(qe_firmware_info.vtraps));

	of_node_put(fw);

	return &qe_firmware_info;
}
EXPORT_SYMBOL(qe_get_firmware_info);

unsigned int qe_get_num_of_risc(void)
{
	struct device_node *qe;
	unsigned int num_of_risc = 0;

	qe = qe_get_device_node();
	if (!qe)
		return num_of_risc;

	of_property_read_u32(qe, "fsl,qe-num-riscs", &num_of_risc);

	of_node_put(qe);

	return num_of_risc;
}
EXPORT_SYMBOL(qe_get_num_of_risc);

unsigned int qe_get_num_of_snums(void)
{
	return qe_num_of_snum;
}
EXPORT_SYMBOL(qe_get_num_of_snums);

static int __init qe_init(void)
{
	struct device_node *np;

	np = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!np)
		return -ENODEV;
	qe_reset();
	of_node_put(np);
	return 0;
}
subsys_initcall(qe_init);

#if defined(CONFIG_SUSPEND) && defined(CONFIG_PPC_85xx)
static int qe_resume(struct platform_device *ofdev)
{
	if (!qe_alive_during_sleep())
		qe_reset();
	return 0;
}

static int qe_probe(struct platform_device *ofdev)
{
	return 0;
}

static const struct of_device_id qe_ids[] = {
	{ .compatible = "fsl,qe", },
	{ },
};

static struct platform_driver qe_driver = {
	.driver = {
		.name = "fsl-qe",
		.of_match_table = qe_ids,
	},
	.probe = qe_probe,
	.resume = qe_resume,
};

builtin_platform_driver(qe_driver);
#endif /* defined(CONFIG_SUSPEND) && defined(CONFIG_PPC_85xx) */