mtd: st_spi_fsm: Allocate resources and register with MTD framework

This is a new driver. It's used to communicate with a special type of
optimised Serial Flash Controller called the FSM. The FSM uses a subset
of the SPI protocol to communicate with supported NOR-Flash devices.

Acked-by Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 01281382180b4c53182d2b07aa4bdd426de34559..1210bc2923b71386b94fd53bd4440d8df137486b 100644 (file)
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -210,6 +210,14 @@ config MTD_DOCG3
          M-Systems and now Sandisk. The support is very experimental,
          and doesn't give access to any write operations.
 
+config MTD_ST_SPI_FSM
+       tristate "ST Microelectronics SPI FSM Serial Flash Controller"
+       depends on ARM || SH
+       help
+         This provides an MTD device driver for the ST Microelectronics
+         SPI Fast Sequence Mode (FSM) Serial Flash Controller and support
+         for a subset of connected Serial Flash devices.
+
 if MTD_DOCG3
 config BCH_CONST_M
        default 14

diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index d83bd73096f67d916525371a5f51a3dec933877f..c68868f605883cab2d9507179a8fd0f340565ce9 100644 (file)
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_MTD_NAND_OMAP_BCH)       += elm.o
 obj-$(CONFIG_MTD_SPEAR_SMI)    += spear_smi.o
 obj-$(CONFIG_MTD_SST25L)       += sst25l.o
 obj-$(CONFIG_MTD_BCM47XXSFLASH)        += bcm47xxsflash.o
+obj-$(CONFIG_MTD_ST_SPI_FSM)    += st_spi_fsm.o
 
 
 CFLAGS_docg3.o                 += -I$(src)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
new file mode 100644 (file)
index 0000000..b1e6740
--- /dev/null
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -0,0 +1,106 @@
+/*
+ * st_spi_fsm.c        - ST Fast Sequence Mode (FSM) Serial Flash Controller
+ *
+ * Author: Angus Clark <angus.clark@st.com>
+ *
+ * Copyright (C) 2010-2014 STicroelectronics Limited
+ *
+ * JEDEC probe based on drivers/mtd/devices/m25p80.c
+ *
+ * This code 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.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+struct stfsm {
+       struct device           *dev;
+       void __iomem            *base;
+       struct resource         *region;
+       struct mtd_info         mtd;
+       struct mutex            lock;
+};
+
+static int stfsm_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct resource *res;
+       struct stfsm *fsm;
+
+       if (!np) {
+               dev_err(&pdev->dev, "No DT found\n");
+               return -EINVAL;
+       }
+
+       fsm = devm_kzalloc(&pdev->dev, sizeof(*fsm), GFP_KERNEL);
+       if (!fsm)
+               return -ENOMEM;
+
+       fsm->dev = &pdev->dev;
+
+       platform_set_drvdata(pdev, fsm);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(&pdev->dev, "Resource not found\n");
+               return -ENODEV;
+       }
+
+       fsm->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(fsm->base)) {
+               dev_err(&pdev->dev,
+                       "Failed to reserve memory region %pR\n", res);
+               return PTR_ERR(fsm->base);
+       }
+
+       mutex_init(&fsm->lock);
+
+       fsm->mtd.dev.parent     = &pdev->dev;
+       fsm->mtd.type           = MTD_NORFLASH;
+       fsm->mtd.writesize      = 4;
+       fsm->mtd.writebufsize   = fsm->mtd.writesize;
+       fsm->mtd.flags          = MTD_CAP_NORFLASH;
+
+       return mtd_device_parse_register(&fsm->mtd, NULL, NULL, NULL, 0);
+}
+
+static int stfsm_remove(struct platform_device *pdev)
+{
+       struct stfsm *fsm = platform_get_drvdata(pdev);
+       int err;
+
+       err = mtd_device_unregister(&fsm->mtd);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static struct of_device_id stfsm_match[] = {
+       { .compatible = "st,spi-fsm", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, stfsm_match);
+
+static struct platform_driver stfsm_driver = {
+       .probe          = stfsm_probe,
+       .remove         = stfsm_remove,
+       .driver         = {
+               .name   = "st-spi-fsm",
+               .owner  = THIS_MODULE,
+               .of_match_table = stfsm_match,
+       },
+};
+module_platform_driver(stfsm_driver);
+
+MODULE_AUTHOR("Angus Clark <angus.clark@st.com>");
+MODULE_DESCRIPTION("ST SPI FSM driver");
+MODULE_LICENSE("GPL");