[PATCH] mtd: physmap_of: add a hook for Versatile write protection
Linus Walleij
linus.walleij at linaro.org
Tue Nov 4 03:34:06 PST 2014
In order to support device tree probing of Versatile flash chips,
there must be a way to add the VPP (write protection) enable/disable
callback. The register in question is in the system controllers
of these platforms.
Solve this by adding a arm,versatile-vpp compatibility to the
device tree node, and look for this. In the driver, add a special
hook to check for the syscon and register a callback if this
property is present. Provide a special Kconfig entry for the addon
hook so it will not be compiled in if the RealView or Integrator
(or later other Versatile boards) are not supported. Stubs in the
header file make sure the impact would be zero on other platforms.
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
drivers/mtd/maps/Kconfig | 10 +
drivers/mtd/maps/Makefile | 1 +
drivers/mtd/maps/physmap_of.c | 5 +
drivers/mtd/maps/physmap_of_versatile.c | 334 ++++++++++++++++++++++++++++++++
drivers/mtd/maps/physmap_of_versatile.h | 19 ++
5 files changed, 369 insertions(+)
create mode 100644 drivers/mtd/maps/physmap_of_versatile.c
create mode 100644 drivers/mtd/maps/physmap_of_versatile.h
diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index ba801d2c6dcc..b01cd6e80774 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -74,6 +74,16 @@ config MTD_PHYSMAP_OF
physically into the CPU's memory. The mapping description here is
taken from OF device tree.
+config MTD_PHYSMAP_OF_VERSATILE
+ bool "Support ARM Versatile physmap OF"
+ depends on MTD_PHYSMAP_OF
+ depends on MFD_SYSCON
+ default y if (REALVIEW_DT || ARCH_INTEGRATOR)
+ help
+ This provides some extra DT physmap parsing for the ARM Versatile
+ platforms, basically to add a VPP (write protection) callback so
+ the flash can be taken out of write protection.
+
config MTD_PMC_MSP_EVM
tristate "CFI Flash device mapped on PMC-Sierra MSP"
depends on PMC_MSP && MTD_CFI
diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index 141c91a5b24c..c60b2b40a592 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_MTD_TSUNAMI) += tsunami_flash.o
obj-$(CONFIG_MTD_PXA2XX) += pxa2xx-flash.o
obj-$(CONFIG_MTD_PHYSMAP) += physmap.o
obj-$(CONFIG_MTD_PHYSMAP_OF) += physmap_of.o
+physmap_of-$(CONFIG_MTD_PHYSMAP_OF_VERSATILE) += physmap_of_versatile.o
obj-$(CONFIG_MTD_PISMO) += pismo.o
obj-$(CONFIG_MTD_PMC_MSP_EVM) += pmcmsp-flash.o
obj-$(CONFIG_MTD_PCMCIA) += pcmciamtd.o
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index c1d21cb501ca..e9b23022ec94 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -24,6 +24,7 @@
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
+#include "physmap_of_versatile.h"
struct of_flash_list {
struct mtd_info *mtd;
@@ -67,6 +68,7 @@ static int of_flash_remove(struct platform_device *dev)
kfree(info->list[i].res);
}
}
+ of_flash_remove_versatile();
return 0;
}
@@ -241,6 +243,9 @@ static int of_flash_probe(struct platform_device *dev)
info->list[i].map.size = res_size;
info->list[i].map.bankwidth = be32_to_cpup(width);
info->list[i].map.device_node = dp;
+ err = of_flash_probe_versatile(&dev->dev, &info->list[i].map);
+ if (err)
+ dev_err(&dev->dev, "Can't probe Versatile VPP\n");
err = -ENOMEM;
info->list[i].map.virt = ioremap(info->list[i].map.phys,
diff --git a/drivers/mtd/maps/physmap_of_versatile.c b/drivers/mtd/maps/physmap_of_versatile.c
new file mode 100644
index 000000000000..f5d55cead0ab
--- /dev/null
+++ b/drivers/mtd/maps/physmap_of_versatile.c
@@ -0,0 +1,334 @@
+/*
+ * Versatile OF physmap driver add-on
+ *
+ * Copyright (c) 2014, Linaro Limited
+ * Author: Linus Walleij <linus.walleij at linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/mtd/map.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include "physmap_of_versatile.h"
+
+/**
+ * struct flashprot_data - per-variant flash protection information
+ * @init: function to call on initialization
+ * @exit: function to call on de-initialization
+ * @set_vpp: function to set the VPP (Voltage for Programming Protection)
+ */
+struct flashprot_data {
+ int (*init)(void);
+ void (*exit)(void);
+ void (*set_vpp)(struct map_info *, int);
+};
+
+struct versatile_flash_prot {
+ struct device *dev;
+ struct regmap *syscon_regmap;
+ struct regmap *ap_ebi_regmap;
+ const struct flashprot_data *fprot;
+};
+
+struct versatile_flash_prot *vprot;
+
+#define INTEGRATOR_SC_CTRLS_OFFSET 0x08 /* For setting bits */
+#define INTEGRATOR_SC_CTRLC_OFFSET 0x0C /* For clearing bits */
+#define INTEGRATOR_SC_CTRL_FLASH_BITS BIT(1) | BIT(2)
+#define INTEGRATOR_SC_CTRL_nFLVPPEN BIT(1)
+#define INTEGRATOR_SC_CTRL_nFLWP BIT(2)
+
+#define INTEGRATOR_EBI_CSR0_OFFSET 0x00
+#define INTEGRATOR_EBI_CSR1_OFFSET 0x04
+#define INTEGRATOR_EBI_CSR2_OFFSET 0x08
+#define INTEGRATOR_EBI_CSR3_OFFSET 0x0C
+#define INTEGRATOR_EBI_LOCK_OFFSET 0x20
+#define INTEGRATOR_EBI_WRITE_ENABLE BIT(2)
+
+static const struct of_device_id ebi_match[] = {
+ { .compatible = "arm,external-bus-interface", },
+ {},
+};
+
+static int integrator_ap_vpp_init(void)
+{
+ struct device_node *ebinp;
+ int ret;
+
+ /* Find the EBI regmap */
+ ebinp = of_find_matching_node(NULL, ebi_match);
+ if (!ebinp) {
+ dev_err(vprot->dev, "no EBI node\n");
+ return -ENODEV;
+ }
+
+ vprot->ap_ebi_regmap = syscon_node_to_regmap(ebinp);
+ if (IS_ERR(vprot->ap_ebi_regmap)) {
+ dev_err(vprot->dev, "no EBI regmap\n");
+ return PTR_ERR(vprot->ap_ebi_regmap);
+ }
+
+ /* Disable VPP and set write protection on startup */
+ ret = regmap_write(vprot->syscon_regmap, INTEGRATOR_SC_CTRLC_OFFSET,
+ INTEGRATOR_SC_CTRL_FLASH_BITS);
+ if (ret) {
+ dev_err(vprot->dev, "failed setting flash protection\n");
+ return ret;
+ }
+
+ /* Unlock EBI */
+ ret = regmap_write(vprot->ap_ebi_regmap, INTEGRATOR_EBI_LOCK_OFFSET,
+ 0xa05f);
+ if (ret) {
+ dev_err(vprot->dev, "failed unlocking EBI\n");
+ return ret;
+ }
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTEGRATOR_EBI_CSR1_OFFSET,
+ INTEGRATOR_EBI_WRITE_ENABLE,
+ INTEGRATOR_EBI_WRITE_ENABLE);
+ if (ret)
+ dev_err(vprot->dev, "failed EBI WE CSR1\n");
+
+ /* Lock EBI */
+ ret = regmap_write(vprot->ap_ebi_regmap, INTEGRATOR_EBI_LOCK_OFFSET, 0);
+ if (ret) {
+ dev_err(vprot->dev, "failed locking EBI\n");
+ return ret;
+ }
+ dev_info(vprot->dev, "initialized Integrator/AP flash protection\n");
+
+ return 0;
+}
+
+static void integrator_ap_vpp_exit(void)
+{
+ int ret;
+
+ if (!vprot || !vprot->syscon_regmap || !vprot->ap_ebi_regmap)
+ return;
+
+ /* Disable VPP and set write protection on exit */
+ ret = regmap_write(vprot->syscon_regmap, INTEGRATOR_SC_CTRLC_OFFSET,
+ INTEGRATOR_SC_CTRL_FLASH_BITS);
+ if (ret)
+ dev_err(vprot->dev, "failed enabling flash protection\n");
+
+ /* Unlock EBI */
+ ret = regmap_write(vprot->ap_ebi_regmap, INTEGRATOR_EBI_LOCK_OFFSET,
+ 0xa05f);
+ if (ret)
+ dev_err(vprot->dev, "failed unlocking EBI\n");
+
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTEGRATOR_EBI_CSR1_OFFSET,
+ INTEGRATOR_EBI_WRITE_ENABLE,
+ 0);
+ if (ret)
+ dev_err(vprot->dev, "failed EBI WE CSR1\n");
+
+ /* Lock EBI */
+ ret = regmap_write(vprot->ap_ebi_regmap, INTEGRATOR_EBI_LOCK_OFFSET, 0);
+ if (ret)
+ dev_err(vprot->dev, "failed locking EBI\n");
+
+ dev_info(vprot->dev, "enabled flash protection\n");
+}
+
+static void integrator_ap_set_vpp(struct map_info *map, int on)
+{
+ int ret;
+
+ if (on) {
+ ret = regmap_write(vprot->syscon_regmap,
+ INTEGRATOR_SC_CTRLS_OFFSET,
+ INTEGRATOR_SC_CTRL_nFLVPPEN);
+ if (ret)
+ dev_err(vprot->dev, "error enable flash VPP\n");
+ } else {
+ ret = regmap_write(vprot->syscon_regmap,
+ INTEGRATOR_SC_CTRLC_OFFSET,
+ INTEGRATOR_SC_CTRL_nFLVPPEN);
+ if (ret)
+ dev_err(vprot->dev, "error disable flash VPP");
+ }
+}
+
+struct flashprot_data integrator_ap_flashprot_data = {
+ .init = integrator_ap_vpp_init,
+ .exit = integrator_ap_vpp_exit,
+ .set_vpp = integrator_ap_set_vpp,
+};
+
+#define INTCP_FLASHPROG 0x04
+#define CINTEGRATOR_FLASHPROG_FLVPPEN BIT(0)
+#define CINTEGRATOR_FLASHPROG_FLWREN BIT(1)
+#define CINTEGRATOR_FLASHPROG_BITS BIT(0) | BIT(1)
+
+#define REALVIEW_FLASH_OFFSET 0x4c
+
+static int integrator_cp_vpp_init(void)
+{
+ int ret;
+
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTCP_FLASHPROG,
+ CINTEGRATOR_FLASHPROG_BITS,
+ CINTEGRATOR_FLASHPROG_FLWREN);
+ if (ret)
+ dev_err(vprot->dev, "failed flash WE\n");
+
+ dev_info(vprot->dev, "initialized Integrator/CP flash protection\n");
+
+ return 0;
+}
+
+static void integrator_cp_vpp_exit(void)
+{
+ int ret;
+
+ if (!vprot || !vprot->syscon_regmap || !vprot->ap_ebi_regmap)
+ return;
+
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTCP_FLASHPROG,
+ CINTEGRATOR_FLASHPROG_BITS,
+ 0);
+ if (ret)
+ dev_err(vprot->dev, "failed flash WE\n");
+
+ dev_info(vprot->dev, "enabled flash protection\n");
+}
+
+static void integrator_cp_set_vpp(struct map_info *map, int on)
+{
+ int ret;
+
+ if (on) {
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTCP_FLASHPROG,
+ CINTEGRATOR_FLASHPROG_FLVPPEN,
+ CINTEGRATOR_FLASHPROG_FLVPPEN);
+ if (ret)
+ dev_err(vprot->dev, "error enable flash VPP\n");
+ } else {
+ ret = regmap_update_bits(vprot->ap_ebi_regmap,
+ INTCP_FLASHPROG,
+ CINTEGRATOR_FLASHPROG_FLVPPEN,
+ 0);
+ if (ret)
+ dev_err(vprot->dev, "error disable flash VPP\n");
+ }
+}
+
+struct flashprot_data integrator_cp_flashprot_data = {
+ .init = integrator_cp_vpp_init,
+ .exit = integrator_cp_vpp_exit,
+ .set_vpp = integrator_cp_set_vpp,
+};
+
+static void realview_set_vpp(struct map_info *map, int on)
+{
+ int ret;
+
+ ret = regmap_update_bits(vprot->syscon_regmap, REALVIEW_FLASH_OFFSET,
+ 0x01, !!on);
+ if (ret)
+ dev_err(vprot->dev, "error setting RealView VPP\n");
+}
+
+struct flashprot_data realview_flashprot_data = {
+ .set_vpp = realview_set_vpp,
+};
+
+static const struct of_device_id syscon_match[] = {
+ {
+ .compatible = "arm,integrator-ap-syscon",
+ .data = &integrator_ap_flashprot_data,
+ },
+ {
+ .compatible = "arm,integrator-cp-syscon",
+ .data = &integrator_cp_flashprot_data,
+ },
+ {
+ .compatible = "arm,realview-pb1176-syscon",
+ .data = &realview_flashprot_data,
+ },
+ {},
+};
+
+int of_flash_probe_versatile(struct device *dev,
+ struct map_info *map)
+{
+ struct device_node *sysnp;
+ const struct of_device_id *devid;
+ struct regmap *rmap;
+ struct device_node *np = dev->of_node;
+
+ vprot = devm_kzalloc(dev, sizeof(*vprot), GFP_KERNEL);
+ if (!vprot)
+ return -ENOMEM;
+ vprot->dev = dev;
+
+ /* Not all flash chips have to use this protection line */
+ if (!of_device_is_compatible(np, "arm,versatile-flash"))
+ return 0;
+
+ /* For first chip probed, look up the syscon regmap */
+ if (!vprot->syscon_regmap) {
+ int ret;
+
+ sysnp = of_find_matching_node_and_match(NULL,
+ syscon_match,
+ &devid);
+ if (!sysnp) {
+ dev_err(dev, "no syscon match\n");
+ return -ENODEV;
+ }
+
+ rmap = syscon_node_to_regmap(sysnp);
+ if (IS_ERR(rmap)) {
+ dev_err(dev, "no syscon regmap\n");
+ return PTR_ERR(rmap);
+ }
+
+ vprot->syscon_regmap = rmap;
+ vprot->fprot = devid->data;
+
+ if (vprot->fprot->init) {
+ ret = vprot->fprot->init();
+ if (ret)
+ return ret;
+ }
+
+ map->set_vpp = vprot->fprot->set_vpp;
+ }
+ return 0;
+}
+
+void of_flash_remove_versatile(void)
+{
+ if (!vprot || !vprot->fprot || !vprot->fprot->exit)
+ return;
+ vprot->fprot->exit();
+}
diff --git a/drivers/mtd/maps/physmap_of_versatile.h b/drivers/mtd/maps/physmap_of_versatile.h
new file mode 100644
index 000000000000..7d176d313860
--- /dev/null
+++ b/drivers/mtd/maps/physmap_of_versatile.h
@@ -0,0 +1,19 @@
+#include <linux/of.h>
+#include <linux/mtd/map.h>
+
+#ifdef CONFIG_MTD_PHYSMAP_OF_VERSATILE
+int of_flash_probe_versatile(struct device *dev,
+ struct map_info *map);
+void of_flash_remove_versatile(void);
+#else
+static inline int
+of_flash_probe_versatile(struct device *dev,
+ struct map_info *map)
+{
+ return 0;
+}
+static inline void
+of_flash_remove_versatile(void)
+{
+}
+#endif
--
1.9.3
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