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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/mtd/devices/bcm47xxsflash.c
Initial import
Diffstat (limited to 'drivers/mtd/devices/bcm47xxsflash.c')
-rw-r--r--drivers/mtd/devices/bcm47xxsflash.c339
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c
new file mode 100644
index 000000000..3d008a941
--- /dev/null
+++ b/drivers/mtd/devices/bcm47xxsflash.c
@@ -0,0 +1,339 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/mtd/mtd.h>
+#include <linux/platform_device.h>
+#include <linux/bcma/bcma.h>
+
+#include "bcm47xxsflash.h"
+
+MODULE_LICENSE("GPL");
+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;
+ int err;
+
+ 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;
+ }
+
+ err = bcm47xxsflash_poll(b47s, HZ);
+ if (err)
+ erase->state = MTD_ERASE_FAILED;
+ else
+ erase->state = MTD_ERASE_DONE;
+
+ if (erase->callback)
+ erase->callback(erase);
+
+ return err;
+}
+
+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;
+
+ /* Check address range */
+ if ((from + len) > mtd->size)
+ return -EINVAL;
+
+ memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(b47s->window + from),
+ len);
+ *retlen = len;
+
+ return 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 0;
+}
+
+static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s)
+{
+ struct mtd_info *mtd = &b47s->mtd;
+
+ mtd->priv = b47s;
+ mtd->name = "bcm47xxsflash";
+ mtd->owner = THIS_MODULE;
+
+ mtd->type = MTD_NORFLASH;
+ mtd->flags = MTD_CAP_NORFLASH;
+ mtd->size = b47s->size;
+ mtd->erasesize = b47s->blocksize;
+ mtd->writesize = 1;
+ mtd->writebufsize = 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 bcm47xxsflash *b47s;
+ int err;
+
+ b47s = devm_kzalloc(&pdev->dev, sizeof(*b47s), GFP_KERNEL);
+ if (!b47s)
+ return -ENOMEM;
+ 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;
+
+ switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) {
+ case BCMA_CC_FLASHT_STSER:
+ b47s->type = BCM47XXSFLASH_TYPE_ST;
+ break;
+ case BCMA_CC_FLASHT_ATSER:
+ b47s->type = BCM47XXSFLASH_TYPE_ATMEL;
+ break;
+ }
+
+ b47s->window = sflash->window;
+ b47s->blocksize = sflash->blocksize;
+ b47s->numblocks = sflash->numblocks;
+ b47s->size = sflash->size;
+ bcm47xxsflash_fill_mtd(b47s);
+
+ err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);
+ if (err) {
+ pr_err("Failed to register MTD device: %d\n", err);
+ return err;
+ }
+
+ if (bcm47xxsflash_poll(b47s, HZ / 10))
+ pr_warn("Serial flash busy\n");
+
+ return 0;
+}
+
+static int bcm47xxsflash_bcma_remove(struct platform_device *pdev)
+{
+ struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev);
+ struct bcm47xxsflash *b47s = sflash->priv;
+
+ mtd_device_unregister(&b47s->mtd);
+
+ return 0;
+}
+
+static struct platform_driver bcma_sflash_driver = {
+ .probe = bcm47xxsflash_bcma_probe,
+ .remove = bcm47xxsflash_bcma_remove,
+ .driver = {
+ .name = "bcma_sflash",
+ },
+};
+
+/**************************************************
+ * Init
+ **************************************************/
+
+module_platform_driver(bcma_sflash_driver);