diff mbox series

[v3,2/3] memory: omap-gpmc: add support for wait pin polarity

Message ID 20220906124747.1767318-3-benedikt.niedermayr@siemens.com (mailing list archive)
State New, archived
Headers show
Series omap-gpmc wait pin additions | expand

Commit Message

Benedikt Niedermayr Sept. 6, 2022, 12:47 p.m. UTC 
From: Benedikt Niedermayr <benedikt.niedermayr@siemens.com>

The waitpin polarity can be configured via the WAITPIN<X>POLARITY bits
in the GPMC_CONFIG register. This is currently not supported by the
driver. This patch adds support for setting the required register bits
with the "gpmc,wait-pin-active-low" device tree property.

Signed-off-by: Benedikt Niedermayr <benedikt.niedermayr@siemens.com>
---
 drivers/memory/omap-gpmc.c              | 15 +++++++++++++++
 include/linux/platform_data/gpmc-omap.h |  1 +
 2 files changed, 16 insertions(+)
diff mbox series

Patch

diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index e3674a15b934..609df21e0ce6 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -132,6 +132,7 @@ 
 #define GPMC_CONFIG_DEV_SIZE	0x00000002
 #define GPMC_CONFIG_DEV_TYPE	0x00000003
 
+#define GPMC_CONFIG_WAITPINPOLARITY(pin)	(BIT(pin) << 8)
 #define GPMC_CONFIG1_WRAPBURST_SUPP     (1 << 31)
 #define GPMC_CONFIG1_READMULTIPLE_SUPP  (1 << 30)
 #define GPMC_CONFIG1_READTYPE_ASYNC     (0 << 29)
@@ -1881,6 +1882,18 @@  int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
 
 	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, config1);
 
+	if (p->wait_on_read || p->wait_on_write) {
+		config1 = gpmc_read_reg(GPMC_CONFIG);
+
+		if (p->wait_pin_active_low)
+			config1 &= ~GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
+		else
+			config1 |= GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
+
+		gpmc_write_reg(GPMC_CONFIG, config1);
+	}
+
+
 	return 0;
 }
 
@@ -1985,6 +1998,8 @@  void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
 							"gpmc,wait-on-read");
 		p->wait_on_write = of_property_read_bool(np,
 							 "gpmc,wait-on-write");
+		p->wait_pin_active_low = of_property_read_bool(np,
+								"gpmc,wait-pin-active-low");
 		if (!p->wait_on_read && !p->wait_on_write)
 			pr_debug("%s: rd/wr wait monitoring not enabled!\n",
 				 __func__);
diff --git a/include/linux/platform_data/gpmc-omap.h b/include/linux/platform_data/gpmc-omap.h
index c9cc4e32435d..7c9675165e8a 100644
--- a/include/linux/platform_data/gpmc-omap.h
+++ b/include/linux/platform_data/gpmc-omap.h
@@ -149,6 +149,7 @@  struct gpmc_settings {
 	u32 device_width;	/* device bus width (8 or 16 bit) */
 	u32 mux_add_data;	/* multiplex address & data */
 	u32 wait_pin;		/* wait-pin to be used */
+	bool wait_pin_active_low;	/* wait-pin polarity */
 };
 
 /* Data for each chip select */