[PATCH v2 05/11] memory: add Atmel EBI (External Bus Interface) driver

2014-11-05 17:59 GMT+01:00 Boris Brezillon [off-list ref]:

On Wed, 5 Nov 2014 17:53:42 +0100
Jean-Jacques Hiblot [off-list ref] wrote:

quoted

2014-11-05 17:01 GMT+01:00 Boris Brezillon [off-list ref]:

quoted

The EBI (External Bus Interface) is used to access external peripherals
(NOR, SRAM, NAND, and other specific devices like ethernet controllers).
Each device is assigned a CS line and an address range and can have its
own configuration (timings, access mode, bus width, ...).
This driver provides a generic DT binding to configure a device according
to its requirements.
For specific device controllers (like the NAND one) the SMC timings
should be configured by the controller driver through the matrix and
smc syscon regmaps.

Signed-off-by: Jean-Jacques Hiblot <redacted>
Signed-off-by: Boris Brezillon <redacted>
---
 drivers/memory/Kconfig     |  11 +
 drivers/memory/Makefile    |   1 +
 drivers/memory/atmel-ebi.c | 615 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 627 insertions(+)
 create mode 100644 drivers/memory/atmel-ebi.c

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 6d91c27..dfe24a2 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig

@@ -17,6 +17,17 @@ config ATMEL_SDRAMC
          Starting with the at91sam9g45, this controller supports SDR, DDR and
          LP-DDR memories.

+config ATMEL_EBI
+       bool "Atmel EBI driver"
+       default y
+       depends on ARCH_AT91 && OF
+       select MFD_SYSCON
+       help
+         Driver for Atmel EBI controller.
+         Used to configure the EBI (external bus interface) when the device-
+         tree is used. This bus supports NANDs, external ethernet controller,
+         SRAMs, ATA devices, etc.
+
 config TI_AEMIF
        tristate "Texas Instruments AEMIF driver"
        depends on (ARCH_DAVINCI || ARCH_KEYSTONE) && OF

diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index c32d319..7ca2c19 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile

@@ -6,6 +6,7 @@ ifeq ($(CONFIG_DDR),y)
 obj-$(CONFIG_OF)               += of_memory.o
 endif
 obj-$(CONFIG_ATMEL_SDRAMC)     += atmel-sdramc.o
+obj-$(CONFIG_ATMEL_EBI)                += atmel-ebi.o
 obj-$(CONFIG_TI_AEMIF)         += ti-aemif.o
 obj-$(CONFIG_TI_EMIF)          += emif.o
 obj-$(CONFIG_FSL_CORENET_CF)   += fsl-corenet-cf.o

diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
new file mode 100644
index 0000000..41bc893
--- /dev/null
+++ b/drivers/memory/atmel-ebi.c

@@ -0,0 +1,615 @@
+/*
+ * EBI driver for Atmel SAM9 chips
+ * inspired by the fsl weim bus driver
+ *
+ * Copyright (C) 2013 JJ Hiblot.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-matrix.h>
+#include <linux/mfd/syscon/atmel-smc.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+#define AT91SAM9_SMC_READ_MODE_MSK     BIT(0)
+#define AT91SAM9_SMC_READ_NCS_MODE     0
+#define AT91SAM9_SMC_READ_NRD_MODE     1
+#define AT91SAM9_SMC_WRITE_MODE_MSK    BIT(1)
+#define AT91SAM9_SMC_WRITE_NCS_MODE    (0 << 1)
+#define AT91SAM9_SMC_WRITE_NWE_MODE    (1 << 1)
+#define AT91SAM9_SMC_EXNW_MODE_MSK     GENMASK(5, 4)
+#define AT91SAM9_SMC_EXNW_DIS          (0 << 4)
+#define AT91SAM9_SMC_EXNW_FROZEN       (2 << 4)
+#define AT91SAM9_SMC_EXNW_READY                (3 << 4)
+#define AT91SAM9_SMC_BAT_MSK           BIT(8)
+#define AT91SAM9_SMC_BAT_SELECT                (0 << 8)
+#define AT91SAM9_SMC_BAT_WRITE         (1 << 8)
+#define AT91SAM9_SMC_DBW_MSK           GENMASK(13, 12)
+#define AT91SAM9_SMC_DBW(x)            ((((x) / 16) & 0x3) << 12)
+#define AT91SAM9_SMC_TDF_CYCLES_MSK    GENMASK(19, 16)
+#define AT91SAM9_SMC_TDF_CYCLES(x)     (((x) & 0xf) << 16)
+#define AT91SAM9_SMC_TDF_MODE_MSK      BIT(20)
+#define AT91SAM9_SMC_TDF_OPTIMIZED     (1 << 20)
+#define AT91SAM9_SMC_PMEN              BIT(24)
+#define AT91SAM9_SMC_PS(x)             ((((x) / 4) & 0x3) << 28)

Those definitions are now also available in
linux/mfd/syscon/atmel-smc.h.For consistency sake, this driver should
probably use the new ones.

That was my intention, I just forgot to cleanup this part...

quoted

BTW this patch should probably be applied after patch 3 "mfd: syscon:
Add atmel-smc registers definition" and patch 1 "mfd: syscon: Add
atmel-matrix registers definition"

And it is: patch 05/11 :-)

Damn gmail again for showing it under [Patch 00/11] ! It's definitely
not the ideal review tool :-)

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com