aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-09-22 00:09:38 +0200
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-11-07 23:43:28 +0100
commit2ae2e28852f21ec9efc527c1f3ecc5f7c7e27e42 (patch)
tree9328c57e974cc1742dda5f7e74f7a45546bd5b46
parent15adffadc59b0430a5e411eb149c39547fc207ce (diff)
misc: sram: add Atmel securam support
The Atmel secure SRAM is connected to a security module and may be erased automatically under certain conditions. For that reason, it is necessary to wait for the security module to flag that SRAM accesses are allowed before accessing it. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/misc/sram.c42
1 files changed, 35 insertions, 7 deletions
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f84b53d..b0d4dd9 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -19,12 +19,17 @@
*/
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/genalloc.h>
#include <linux/io.h>
#include <linux/list_sort.h>
#include <linux/of_address.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <soc/at91/atmel-secumod.h>
#define SRAM_GRANULARITY 32
@@ -334,12 +339,35 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
return ret;
}
+static int atmel_securam_wait(void)
+{
+ struct regmap *regmap;
+ u32 val;
+
+ regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
+ if (IS_ERR(regmap))
+ return -ENODEV;
+
+ return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
+ val & AT91_SECUMOD_RAMRDY_READY,
+ 10000, 500000);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sram_dt_ids[] = {
+ { .compatible = "mmio-sram" },
+ { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
+ {}
+};
+#endif
+
static int sram_probe(struct platform_device *pdev)
{
struct sram_dev *sram;
struct resource *res;
size_t size;
int ret;
+ int (*init_func)(void);
sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
if (!sram)
@@ -384,6 +412,13 @@ static int sram_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, sram);
+ init_func = of_device_get_match_data(&pdev->dev);
+ if (init_func) {
+ ret = init_func();
+ if (ret)
+ return ret;
+ }
+
dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
gen_pool_size(sram->pool) / 1024, sram->virt_base);
@@ -405,13 +440,6 @@ static int sram_remove(struct platform_device *pdev)
return 0;
}
-#ifdef CONFIG_OF
-static const struct of_device_id sram_dt_ids[] = {
- { .compatible = "mmio-sram" },
- {}
-};
-#endif
-
static struct platform_driver sram_driver = {
.driver = {
.name = "sram",