[PATCH 2/2] MTD: MIPS: lantiq: Add NAND support on Lantiq XWAY SoC.
John Crispin
blogic at openwrt.org
Sun Jul 22 02:59:58 EDT 2012
The driver uses plat_nand. As the platform_device is loaded from DT, we need
to lookup the node and attach our xway specific "struct platform_nand_data"
to it.
Signed-off-by: John Crispin <blogic at openwrt.org>
Acked-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
Cc: linux-mtd at lists.infradead.org
---
drivers/mtd/nand/Kconfig | 8 ++
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/xway_nand.c | 200 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 209 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/nand/xway_nand.c
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f4e81a7..ffa46ca 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -589,4 +589,12 @@ config MTD_NAND_FSMC
Enables support for NAND Flash chips on the ST Microelectronics
Flexible Static Memory Controller (FSMC)
+config MTD_NAND_XWAY
+ tristate "Support for NAND on Lantiq XWAY SoC"
+ depends on LANTIQ && SOC_TYPE_XWAY
+ select MTD_NAND_PLATFORM
+ help
+ Enables support for NAND Flash chips on Lantiq XWAY SoCs. NAND is attached
+ to the External Bus Unit (EBU).
+
endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index ddee818..c4b0ab3 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -53,5 +53,6 @@ obj-$(CONFIG_MTD_NAND_MPC5121_NFC) += mpc5121_nfc.o
obj-$(CONFIG_MTD_NAND_RICOH) += r852.o
obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
obj-$(CONFIG_MTD_NAND_GPMI_NAND) += gpmi-nand/
+obj-$(CONFIG_MTD_NAND_XWAY) += xway_nand.o
nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c
new file mode 100644
index 0000000..e4cd00d
--- /dev/null
+++ b/drivers/mtd/nand/xway_nand.c
@@ -0,0 +1,200 @@
+/*
+ * This program 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.
+ *
+ * Copyright (C) 2012 John Crispin <blogic at openwrt.org>
+ */
+
+#include <linux/mtd/nand.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+
+#include <lantiq_soc.h>
+
+/* nand registers */
+#define EBU_ADDSEL1 0x24
+#define EBU_NAND_CON 0xB0
+#define EBU_NAND_WAIT 0xB4
+#define EBU_NAND_ECC0 0xB8
+#define EBU_NAND_ECC_AC 0xBC
+
+/* nand commands */
+#define NAND_CMD_ALE (1 << 2)
+#define NAND_CMD_CLE (1 << 3)
+#define NAND_CMD_CS (1 << 4)
+#define NAND_WRITE_CMD_RESET 0xff
+#define NAND_WRITE_CMD (NAND_CMD_CS | NAND_CMD_CLE)
+#define NAND_WRITE_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
+#define NAND_WRITE_DATA (NAND_CMD_CS)
+#define NAND_READ_DATA (NAND_CMD_CS)
+#define NAND_WAIT_WR_C (1 << 3)
+#define NAND_WAIT_RD (0x1)
+
+/* we need to tel the ebu which addr we mapped the nand to */
+#define ADDSEL1_MASK(x) (x << 4)
+#define ADDSEL1_REGEN 1
+
+/* we need to tell the EBU that we have nand attached and set it up properly */
+#define BUSCON1_SETUP (1 << 22)
+#define BUSCON1_BCGEN_RES (0x3 << 12)
+#define BUSCON1_WAITWRC2 (2 << 8)
+#define BUSCON1_WAITRDC2 (2 << 6)
+#define BUSCON1_HOLDC1 (1 << 4)
+#define BUSCON1_RECOVC1 (1 << 2)
+#define BUSCON1_CMULT4 1
+
+#define NAND_CON_CE (1 << 20)
+#define NAND_CON_OUT_CS1 (1 << 10)
+#define NAND_CON_IN_CS1 (1 << 8)
+#define NAND_CON_PRE_P (1 << 7)
+#define NAND_CON_WP_P (1 << 6)
+#define NAND_CON_SE_P (1 << 5)
+#define NAND_CON_CS_P (1 << 4)
+#define NAND_CON_CSMUX (1 << 1)
+#define NAND_CON_NANDM 1
+
+static void xway_reset_chip(struct nand_chip *chip)
+{
+ unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
+ unsigned long flags;
+
+ nandaddr &= ~NAND_WRITE_ADDR;
+ nandaddr |= NAND_WRITE_CMD;
+
+ /* finish with a reset */
+ spin_lock_irqsave(&ebu_lock, flags);
+ writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
+ while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+ ;
+ spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
+static void xway_select_chip(struct mtd_info *mtd, int chip)
+{
+
+ switch (chip) {
+ case -1:
+ ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
+ ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
+ break;
+ case 0:
+ ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
+ ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+ struct nand_chip *this = mtd->priv;
+ unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
+ unsigned long flags;
+
+ if (ctrl & NAND_CTRL_CHANGE) {
+ nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR);
+ if (ctrl & NAND_CLE)
+ nandaddr |= NAND_WRITE_CMD;
+ else
+ nandaddr |= NAND_WRITE_ADDR;
+ this->IO_ADDR_W = (void __iomem *) nandaddr;
+ }
+
+ if (cmd != NAND_CMD_NONE) {
+ spin_lock_irqsave(&ebu_lock, flags);
+ writeb(cmd, this->IO_ADDR_W);
+ while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+ ;
+ spin_unlock_irqrestore(&ebu_lock, flags);
+ }
+}
+
+static int xway_dev_ready(struct mtd_info *mtd)
+{
+ return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
+}
+
+static unsigned char xway_read_byte(struct mtd_info *mtd)
+{
+ struct nand_chip *this = mtd->priv;
+ unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&ebu_lock, flags);
+ ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
+ spin_unlock_irqrestore(&ebu_lock, flags);
+
+ return ret;
+}
+
+static int xway_nand_probe(struct platform_device *pdev)
+{
+ struct nand_chip *this = platform_get_drvdata(pdev);
+ const __be32 *cs = of_get_property(pdev->dev.of_node,
+ "lantiq,cs", NULL);
+ u32 cs_flag = 0;
+
+ /* load our CS from the DT. Either we find a valid 1 or default to 0 */
+ if (cs && (*cs == 1))
+ cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
+
+ /* setup the EBU to run in NAND mode on our base addr */
+ ltq_ebu_w32((CPHYSADDR(this->IO_ADDR_W) & 0x1fffff00)
+ | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
+
+ ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
+ | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
+ | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
+
+ ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
+ | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
+ | cs_flag, EBU_NAND_CON);
+
+ /* finish with a reset */
+ xway_reset_chip(this);
+
+ return 0;
+}
+
+/* allow users to override the partition in DT using the cmdline */
+static const char const *part_probes[] = { "cmdlinepart", "ofpart", NULL };
+
+static struct platform_nand_data xway_nand_data = {
+ .chip = {
+ .nr_chips = 1,
+ .chip_delay = 30,
+ .part_probe_types = part_probes,
+ },
+ .ctrl = {
+ .probe = xway_nand_probe,
+ .cmd_ctrl = xway_cmd_ctrl,
+ .dev_ready = xway_dev_ready,
+ .select_chip = xway_select_chip,
+ .read_byte = xway_read_byte,
+ }
+};
+
+/*
+ * Try to find the node inside the DT. If it is available attach out
+ * platform_nand_data
+ */
+int __init xway_register_nand(void)
+{
+ struct device_node *node;
+ struct platform_device *pdev;
+
+ node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway");
+ if (!node)
+ return -ENOENT;
+ pdev = of_find_device_by_node(node);
+ if (!pdev)
+ return -EINVAL;
+ pdev->dev.platform_data = &xway_nand_data;
+ of_node_put(node);
+ return 0;
+}
+
+subsys_initcall(xway_register_nand);
--
1.7.9.1
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