[PATCH v3 06/10] mtd: brcmstb_nand: add SoC-specific support

Brian Norris
2015-05-06T17:59:50Z

The STB NAND controller is integrated into various non-STB SoCs, and
those SoCs integrate things like interrupts and busing differently. Add
support for masking/clearing interrupts via a custom hook, as well as
preparing/unpreparing the data bus for data transfers.

Does not support any new SoCs yet; support will be added incrementally.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
drivers/mtd/nand/Makefile | 3 +-
drivers/mtd/nand/brcmnand.h | 56 +++++++++++++++++++++++++++
drivers/mtd/nand/brcmstb_nand.c | 75 ++++++++++++++++++++++++++++++++++---
drivers/mtd/nand/brcmstb_nand_soc.c | 65 ++++++++++++++++++++++++++++++++
4 files changed, 193 insertions(+), 6 deletions(-)
create mode 100644 drivers/mtd/nand/brcmnand.h
create mode 100644 drivers/mtd/nand/brcmstb_nand_soc.c

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 3b1adddc83dd..806727d5a84b 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_MTD_NAND_XWAY) += xway_nand.o
obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH) += bcm47xxnflash/
obj-$(CONFIG_MTD_NAND_SUNXI) += sunxi_nand.o
obj-$(CONFIG_MTD_NAND_HISI504) += hisi504_nand.o
-obj-$(CONFIG_MTD_NAND_BRCMSTB) += brcmstb_nand.o
+obj-$(CONFIG_MTD_NAND_BRCMSTB) += brcmnand.o
+brcmnand-objs := brcmstb_nand.o brcmstb_nand_soc.o

nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/brcmnand.h b/drivers/mtd/nand/brcmnand.h
new file mode 100644
index 000000000000..59e0bfef2331
--- /dev/null
+++ b/drivers/mtd/nand/brcmnand.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2015 Broadcom Corporation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __BRCMNAND_H__
+#define __BRCMNAND_H__
+
+#include <linux/types.h>
+
+struct device;
+struct device_node;
+
+struct brcmnand_soc {
+ struct device *dev; /* parent device */
+ struct device_node *dn;
+ bool (*ctlrdy_ack)(struct brcmnand_soc *soc);
+ void (*ctlrdy_set_enabled)(struct brcmnand_soc *soc, bool en);
+ void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare);
+ void *priv;
+};
+
+/**
+ * Probe for a custom Broadcom SoC
+ *
+ * @dev: device to bind devres objects to
+ * @dn: DT node for the custom SoC
+ *
+ * Return a new soc struct if successful. Should be freed with
+ * brcmnand_remove_soc().
+ * Return NULL for all other errors
+ */
+struct brcmnand_soc *devm_brcmnand_probe_soc(struct device *dev,
+ struct device_node *dn);
+
+static inline void brcmnand_soc_data_bus_prepare(struct brcmnand_soc *soc)
+{
+ if (soc && soc->prepare_data_bus)
+ soc->prepare_data_bus(soc, true);
+}
+
+static inline void brcmnand_soc_data_bus_unprepare(struct brcmnand_soc *soc)
+{
+ if (soc && soc->prepare_data_bus)
+ soc->prepare_data_bus(soc, false);
+}
+
+#endif /* __BRCMNAND_H__ */
diff --git a/drivers/mtd/nand/brcmstb_nand.c b/drivers/mtd/nand/brcmstb_nand.c
index ec65a48d2487..5abc88cfe702 100644
--- a/drivers/mtd/nand/brcmstb_nand.c
+++ b/drivers/mtd/nand/brcmstb_nand.c
@@ -37,6 +37,8 @@
#include <linux/list.h>
#include <linux/log2.h>

+#include "brcmnand.h"
+
/*
* This flag controls if WP stays on between erase/write commands to mitigate
* flash corruption due to power glitches. Values:
@@ -117,6 +119,9 @@ struct brcmnand_controller {
unsigned int dma_irq;
int nand_version;

+ /* Some SoCs provide custom interrupt status register(s) */
+ struct brcmnand_soc *soc;
+
int cmd_pending;
bool dma_pending;
struct completion done;
@@ -963,6 +968,17 @@ static irqreturn_t brcmnand_ctlrdy_irq(int irq, void *data)
return IRQ_HANDLED;
}

+/* Handle SoC-specific interrupt hardware */
+static irqreturn_t brcmnand_irq(int irq, void *data)
+{
+ struct brcmnand_controller *ctrl = data;
+
+ if (ctrl->soc->ctlrdy_ack(ctrl->soc))
+ return brcmnand_ctlrdy_irq(irq, data);
+
+ return IRQ_NONE;
+}
+
static irqreturn_t brcmnand_dma_irq(int irq, void *data)
{
struct brcmnand_controller *ctrl = data;
@@ -1151,12 +1167,18 @@ static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
if (native_cmd == CMD_PARAMETER_READ ||
native_cmd == CMD_PARAMETER_CHANGE_COL) {
int i;
+
+ brcmnand_soc_data_bus_prepare(ctrl->soc);
+
/*
* Must cache the FLASH_CACHE now, since changes in
* SECTOR_SIZE_1K may invalidate it
*/
for (i = 0; i < FC_WORDS; i++)
ctrl->flash_cache[i] = brcmnand_read_fc(ctrl, i);
+
+ brcmnand_soc_data_bus_unprepare(ctrl->soc);
+
/* Cleanup from HW quirk: restore SECTOR_SIZE_1K */
if (host->hwcfg.sector_size_1k)
brcmnand_set_sector_size_1k(host,
@@ -1369,10 +1391,15 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
brcmnand_send_cmd(host, CMD_PAGE_READ);
brcmnand_waitfunc(mtd, chip);

- if (likely(buf))
+ if (likely(buf)) {
+ brcmnand_soc_data_bus_prepare(ctrl->soc);
+
for (j = 0; j < FC_WORDS; j++, buf++)
*buf = brcmnand_read_fc(ctrl, j);

+ brcmnand_soc_data_bus_unprepare(ctrl->soc);
+ }
+
if (oob)
oob += read_oob_from_regs(ctrl, i, oob,
mtd->oobsize / trans,
@@ -1544,12 +1571,17 @@ static int brcmnand_write(struct mtd_info *mtd, struct nand_chip *chip,
lower_32_bits(addr));
(void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS);

- if (buf)
+ if (buf) {
+ brcmnand_soc_data_bus_prepare(ctrl->soc);
+
for (j = 0; j < FC_WORDS; j++, buf++)
brcmnand_write_fc(ctrl, j, *buf);
- else if (oob)
+
+ brcmnand_soc_data_bus_unprepare(ctrl->soc);
+ } else if (oob) {
for (j = 0; j < FC_WORDS; j++)
brcmnand_write_fc(ctrl, j, 0xffffffff);
+ }

if (oob) {
oob += write_oob_to_regs(ctrl, i, oob,
@@ -1993,6 +2025,11 @@ static int brcmnand_resume(struct device *dev)
brcmnand_write_reg(ctrl, BRCMNAND_CS_XOR, ctrl->nand_cs_nand_xor);
brcmnand_write_reg(ctrl, BRCMNAND_CORR_THRESHOLD,
ctrl->corr_stat_threshold);
+ if (ctrl->soc) {
+ /* Clear/re-enable interrupt */
+ ctrl->soc->ctlrdy_ack(ctrl->soc);
+ ctrl->soc->ctlrdy_set_enabled(ctrl->soc, true);
+ }

list_for_each_entry(host, &ctrl->host_list, node) {
struct mtd_info *mtd = &host->mtd;
@@ -2122,8 +2159,36 @@ static int brcmnand_probe(struct platform_device *pdev)
return -ENODEV;
}

- ret = devm_request_irq(dev, ctrl->irq, brcmnand_ctlrdy_irq, 0,
- DRV_NAME, ctrl);
+ /*
+ * Some SoCs integrate this controller (e.g., its interrupt bits) in
+ * interesting ways
+ */
+ if (of_property_read_bool(dn, "brcm,nand-soc")) {
+ struct device_node *soc_dn;
+
+ soc_dn = of_parse_phandle(dn, "brcm,nand-soc", 0);
+ if (!soc_dn)
+ return -ENODEV;
+
+ ctrl->soc = devm_brcmnand_probe_soc(dev, soc_dn);
+ if (!ctrl->soc) {
+ dev_err(dev, "could not probe SoC data\n");
+ of_node_put(soc_dn);
+ return -ENODEV;
+ }
+
+ ret = devm_request_irq(dev, ctrl->irq, brcmnand_irq, 0,
+ DRV_NAME, ctrl);
+
+ /* Enable interrupt */
+ ctrl->soc->ctlrdy_set_enabled(ctrl->soc, true);
+
+ of_node_put(soc_dn);
+ } else {
+ /* Use standard interrupt infrastructure */
+ ret = devm_request_irq(dev, ctrl->irq, brcmnand_ctlrdy_irq, 0,
+ DRV_NAME, ctrl);
+ }
if (ret < 0) {
dev_err(dev, "can't allocate IRQ %d: error %d\n",
ctrl->irq, ret);
diff --git a/drivers/mtd/nand/brcmstb_nand_soc.c b/drivers/mtd/nand/brcmstb_nand_soc.c
new file mode 100644
index 000000000000..970912c690a7
--- /dev/null
+++ b/drivers/mtd/nand/brcmstb_nand_soc.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright © 2015 Broadcom Corporation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "brcmnand.h"
+
+#define DRV_NAME "brcmnand-soc"
+
+struct brcmnand_soc_ofdata {
+ int (*init)(struct brcmnand_soc *soc);
+ bool (*ctlrdy_ack)(struct brcmnand_soc *soc);
+ void (*ctlrdy_set_enabled)(struct brcmnand_soc *soc, bool en);
+ void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare);
+};
+
+static const struct of_device_id brcmnand_soc_ofmatch[] = {
+ {},
+};
+
+struct brcmnand_soc *devm_brcmnand_probe_soc(struct device *dev,
+ struct device_node *dn)
+{
+ const struct brcmnand_soc_ofdata *soc_data;
+ const struct of_device_id *match;
+ struct brcmnand_soc *soc;
+ int ret;
+
+ match = of_match_node(brcmnand_soc_ofmatch, dn);
+ if (!match)
+ return NULL;
+
+ soc_data = match->data;
+
+ soc = devm_kzalloc(dev, sizeof(*soc), GFP_KERNEL);
+ if (!soc)
+ return NULL;
+
+ soc->dev = dev;
+ soc->dn = dn;
+ soc->ctlrdy_ack = soc_data->ctlrdy_ack;
+ soc->ctlrdy_set_enabled = soc_data->ctlrdy_set_enabled;
+ soc->prepare_data_bus = soc_data->prepare_data_bus;
+ if (soc_data->init) {
+ ret = soc_data->init(soc);
+ if (ret)
+ return NULL;
+ }
+
+ return soc;
+}
--
1.9.1