1 files changed, 294 insertions, 51 deletions

diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c
index 18e7761137a3..2edc46741774 100644
--- a/drivers/mtd/devices/bcm47xxsflash.c
+++ b/drivers/mtd/devices/bcm47xxsflash.c
@@ -1,6 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
 #include <linux/mtd/mtd.h>
 #include <linux/platform_device.h>
 #include <linux/bcma/bcma.h>
@@ -12,56 +15,318 @@ MODULE_DESCRIPTION("Serial flash driver for BCMA bus");
 
 static const char * const probes[] = { "bcm47xxpart", NULL };
 
+/**************************************************
+ * Various helpers
+ **************************************************/
+
+static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
+{
+	int i;
+
+	b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
+	for (i = 0; i < 1000; i++) {
+		if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
+		      BCMA_CC_FLASHCTL_BUSY))
+			return;
+		cpu_relax();
+	}
+	pr_err("Control command failed (timeout)!\n");
+}
+
+static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
+{
+	unsigned long deadline = jiffies + timeout;
+
+	do {
+		switch (b47s->type) {
+		case BCM47XXSFLASH_TYPE_ST:
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
+			if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+			      SR_ST_WIP))
+				return 0;
+			break;
+		case BCM47XXSFLASH_TYPE_ATMEL:
+			bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
+			if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+			    SR_AT_READY)
+				return 0;
+			break;
+		}
+
+		cpu_relax();
+		udelay(1);
+	} while (!time_after_eq(jiffies, deadline));
+
+	pr_err("Timeout waiting for flash to be ready!\n");
+
+	return -EBUSY;
+}
+
+/**************************************************
+ * MTD ops
+ **************************************************/
+
+static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+
+	switch (b47s->type) {
+	case BCM47XXSFLASH_TYPE_ST:
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr);
+		/* Newer flashes have "sub-sectors" which can be erased
+		 * independently with a new command: ST_SSE. The ST_SE command
+		 * erases 64KB just as before.
+		 */
+		if (b47s->blocksize < (64 * 1024))
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE);
+		else
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_SE);
+		break;
+	case BCM47XXSFLASH_TYPE_ATMEL:
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE);
+		break;
+	}
+
+	return bcm47xxsflash_poll(b47s, HZ);
+}
+
 static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
 			      size_t *retlen, u_char *buf)
 {
 	struct bcm47xxsflash *b47s = mtd->priv;
+	size_t orig_len = len;
 
 	/* Check address range */
 	if ((from + len) > mtd->size)
 		return -EINVAL;
 
-	memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(b47s->window + from),
-		      len);
-	*retlen = len;
+	/* Read as much as possible using fast MMIO window */
+	if (from < BCM47XXSFLASH_WINDOW_SZ) {
+		size_t memcpy_len;
+
+		memcpy_len = min(len, (size_t)(BCM47XXSFLASH_WINDOW_SZ - from));
+		memcpy_fromio(buf, b47s->window + from, memcpy_len);
+		from += memcpy_len;
+		len -= memcpy_len;
+		buf += memcpy_len;
+	}
+
+	/* Use indirect access for content out of the window */
+	for (; len; len--) {
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, from++);
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_READ4B);
+		*buf++ = b47s->cc_read(b47s, BCMA_CC_FLASHDATA);
+	}
+
+	*retlen = orig_len;
+
+	return orig_len;
+}
+
+static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,
+				  const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	int written = 0;
+
+	/* Enable writes */
+	bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
+
+	/* Write first byte */
+	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset);
+	b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
+
+	/* Program page */
+	if (b47s->bcma_cc->core->id.rev < 20) {
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_PP);
+		return 1; /* 1B written */
+	}
+
+	/* Program page and set CSA (on newer chips we can continue writing) */
+	bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP);
+	offset++;
+	len--;
+	written++;
+
+	while (len > 0) {
+		/* Page boundary, another function call is needed */
+		if ((offset & 0xFF) == 0)
+			break;
+
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++);
+		offset++;
+		len--;
+		written++;
+	}
+
+	/* All done, drop CSA & poll */
+	b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0);
+	udelay(1);
+	if (bcm47xxsflash_poll(b47s, HZ / 10))
+		pr_err("Flash rejected dropping CSA\n");
+
+	return written;
+}
+
+static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len,
+				  const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	u32 mask = b47s->blocksize - 1;
+	u32 page = (offset & ~mask) << 1;
+	u32 byte = offset & mask;
+	int written = 0;
+
+	/* If we don't overwrite whole page, read it to the buffer first */
+	if (byte || (len < b47s->blocksize)) {
+		int err;
+
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD);
+		/* 250 us for AT45DB321B */
+		err = bcm47xxsflash_poll(b47s, HZ / 1000);
+		if (err) {
+			pr_err("Timeout reading page 0x%X info buffer\n", page);
+			return err;
+		}
+	}
+
+	/* Change buffer content with our data */
+	while (len > 0) {
+		/* Page boundary, another function call is needed */
+		if (byte == b47s->blocksize)
+			break;
+
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++);
+		b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE);
+		len--;
+		written++;
+	}
+
+	/* Program page with the buffer content */
+	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
+	bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM);
+
+	return written;
+}
+
+static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len,
+			       size_t *retlen, const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	int written;
+
+	/* Writing functions can return without writing all passed data, for
+	 * example when the hardware is too old or when we git page boundary.
+	 */
+	while (len > 0) {
+		switch (b47s->type) {
+		case BCM47XXSFLASH_TYPE_ST:
+			written = bcm47xxsflash_write_st(mtd, to, len, buf);
+			break;
+		case BCM47XXSFLASH_TYPE_ATMEL:
+			written = bcm47xxsflash_write_at(mtd, to, len, buf);
+			break;
+		default:
+			BUG_ON(1);
+		}
+		if (written < 0) {
+			pr_err("Error writing at offset 0x%llX\n", to);
+			return written;
+		}
+		to += (loff_t)written;
+		len -= written;
+		*retlen += written;
+		buf += written;
+	}
 
-	return len;
+	return 0;
 }
 
-static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s)
+static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s,
+				   struct device *dev)
 {
 	struct mtd_info *mtd = &b47s->mtd;
 
 	mtd->priv = b47s;
+	mtd->dev.parent = dev;
 	mtd->name = "bcm47xxsflash";
-	mtd->owner = THIS_MODULE;
-	mtd->type = MTD_ROM;
+
+	mtd->type = MTD_NORFLASH;
+	mtd->flags = MTD_CAP_NORFLASH;
 	mtd->size = b47s->size;
-	mtd->_read = bcm47xxsflash_read;
+	mtd->erasesize = b47s->blocksize;
+	mtd->writesize = 1;
+	mtd->writebufsize = 1;
 
-	/* TODO: implement writing support and verify/change following code */
-	mtd->flags = MTD_CAP_ROM;
-	mtd->writebufsize = mtd->writesize = 1;
+	mtd->_erase = bcm47xxsflash_erase;
+	mtd->_read = bcm47xxsflash_read;
+	mtd->_write = bcm47xxsflash_write;
 }
 
 /**************************************************
  * BCMA
  **************************************************/
 
+static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset)
+{
+	return bcma_cc_read32(b47s->bcma_cc, offset);
+}
+
+static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset,
+					u32 value)
+{
+	bcma_cc_write32(b47s->bcma_cc, offset, value);
+}
+
 static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
 {
-	struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev);
+	struct device *dev = &pdev->dev;
+	struct bcma_sflash *sflash = dev_get_platdata(dev);
 	struct bcm47xxsflash *b47s;
+	struct resource *res;
 	int err;
 
-	b47s = kzalloc(sizeof(*b47s), GFP_KERNEL);
-	if (!b47s) {
-		err = -ENOMEM;
-		goto out;
+	b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL);
+	if (!b47s)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "invalid resource\n");
+		return -EINVAL;
+	}
+	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+				     res->name)) {
+		dev_err(dev, "can't request region for resource %pR\n", res);
+		return -EBUSY;
 	}
-	sflash->priv = b47s;
 
 	b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash);
+	b47s->cc_read = bcm47xxsflash_bcma_cc_read;
+	b47s->cc_write = bcm47xxsflash_bcma_cc_write;
+
+	/*
+	 * On old MIPS devices cache was magically invalidated when needed,
+	 * allowing us to use cached access and gain some performance. Trying
+	 * the same on ARM based BCM53573 results in flash corruptions, we need
+	 * to use uncached access for it.
+	 *
+	 * It may be arch specific, but right now there is only 1 ARM SoC using
+	 * this driver, so let's follow Broadcom's reference code and check
+	 * ChipCommon revision.
+	 */
+	if (b47s->bcma_cc->core->id.rev == 54)
+		b47s->window = ioremap(res->start, resource_size(res));
+	else
+		b47s->window = ioremap_cache(res->start, resource_size(res));
+	if (!b47s->window) {
+		dev_err(dev, "ioremap failed for resource %pR\n", res);
+		return -ENOMEM;
+	}
 
 	switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) {
 	case BCMA_CC_FLASHT_STSER:
@@ -72,35 +337,32 @@ static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
 		break;
 	}
 
-	b47s->window = sflash->window;
 	b47s->blocksize = sflash->blocksize;
 	b47s->numblocks = sflash->numblocks;
 	b47s->size = sflash->size;
-	bcm47xxsflash_fill_mtd(b47s);
+	bcm47xxsflash_fill_mtd(b47s, &pdev->dev);
+
+	platform_set_drvdata(pdev, b47s);
 
 	err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);
 	if (err) {
 		pr_err("Failed to register MTD device: %d\n", err);
-		goto err_dev_reg;
+		iounmap(b47s->window);
+		return err;
 	}
 
-	return 0;
+	if (bcm47xxsflash_poll(b47s, HZ / 10))
+		pr_warn("Serial flash busy\n");
 
-err_dev_reg:
-	kfree(&b47s->mtd);
-out:
-	return err;
+	return 0;
 }
 
-static int bcm47xxsflash_bcma_remove(struct platform_device *pdev)
+static void bcm47xxsflash_bcma_remove(struct platform_device *pdev)
 {
-	struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev);
-	struct bcm47xxsflash *b47s = sflash->priv;
+	struct bcm47xxsflash *b47s = platform_get_drvdata(pdev);
 
 	mtd_device_unregister(&b47s->mtd);
-	kfree(b47s);
-
-	return 0;
+	iounmap(b47s->window);
 }
 
 static struct platform_driver bcma_sflash_driver = {
@@ -108,7 +370,6 @@ static struct platform_driver bcma_sflash_driver = {
 	.remove = bcm47xxsflash_bcma_remove,
 	.driver = {
 		.name = "bcma_sflash",
-		.owner = THIS_MODULE,
 	},
 };
 
@@ -116,22 +377,4 @@ static struct platform_driver bcma_sflash_driver = {
  * Init
  **************************************************/
 
-static int __init bcm47xxsflash_init(void)
-{
-	int err;
-
-	err = platform_driver_register(&bcma_sflash_driver);
-	if (err)
-		pr_err("Failed to register BCMA serial flash driver: %d\n",
-		       err);
-
-	return err;
-}
-
-static void __exit bcm47xxsflash_exit(void)
-{
-	platform_driver_unregister(&bcma_sflash_driver);
-}
-
-module_init(bcm47xxsflash_init);
-module_exit(bcm47xxsflash_exit);
+module_platform_driver(bcma_sflash_driver);