Hi Neil, great to see progress towards supporting OX820! The NAND driver I hacked up for Kernel 4.1 and 4.4 in OpenWrt/LEDE looks very similar, see
https://git.lede-project.org/?p=lede/dangole/staging.git;a=blob;f=target/linux/oxnas/files/drivers/mtd/nand/oxnas_nand.c;h=f5a142950e32227fee304de731e619278350a91b;hb=refs/heads/oxnas-nand To me therefore this looks quite good, just one small question below. Cheers Daniel On Tue, Oct 18, 2016 at 11:09:27AM +0200, Neil Armstrong wrote: > Add NAND driver to support the Oxford Semiconductor OX820 NAND Controller. > This is a simple memory mapped NAND controller with single chip select and > software ECC. > > Signed-off-by: Neil Armstrong <narmstr...@baylibre.com> > --- > .../devicetree/bindings/mtd/oxnas-nand.txt | 24 ++++ > drivers/mtd/nand/Kconfig | 5 + > drivers/mtd/nand/Makefile | 1 + > drivers/mtd/nand/oxnas_nand.c | 144 > +++++++++++++++++++++ > 4 files changed, 174 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/oxnas-nand.txt > create mode 100644 drivers/mtd/nand/oxnas_nand.c > > diff --git a/Documentation/devicetree/bindings/mtd/oxnas-nand.txt > b/Documentation/devicetree/bindings/mtd/oxnas-nand.txt > new file mode 100644 > index 0000000..83b684d > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/oxnas-nand.txt > @@ -0,0 +1,24 @@ > +* Oxford Semiconductor OXNAS NAND Controller > + > +Please refer to nand.txt for generic information regarding MTD NAND bindings. > + > +Required properties: > + - compatible: "oxsemi,ox820-nand" > + - reg: Base address and length for NAND mapped memory. > + > +Optional Properties: > + - clocks: phandle to the NAND gate clock if needed. > + - resets: phandle to the NAND reset control if needed. > + > +Example: > + > +nand: nand@41000000 { > + compatible = "oxsemi,ox820-nand"; > + reg = <0x41000000 0x100000>; > + nand-ecc-mode = "soft"; > + clocks = <&stdclk CLK_820_NAND>; > + resets = <&reset RESET_NAND>; > + #address-cells = <1>; > + #size-cells = <1>; > + status = "disabled"; > +}; > diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig > index 7b7a887..c023125 100644 > --- a/drivers/mtd/nand/Kconfig > +++ b/drivers/mtd/nand/Kconfig > @@ -426,6 +426,11 @@ config MTD_NAND_ORION > No board specific support is done by this driver, each board > must advertise a platform_device for the driver to attach. > > +config MTD_NAND_OXNAS > + tristate "NAND Flash support for Oxford Semiconductor SoC" > + help > + This enables the NAND flash controller on Oxford Semiconductor SoCs. > + > config MTD_NAND_FSL_ELBC > tristate "NAND support for Freescale eLBC controllers" > depends on FSL_SOC > diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile > index cafde6f..05fc054 100644 > --- a/drivers/mtd/nand/Makefile > +++ b/drivers/mtd/nand/Makefile > @@ -35,6 +35,7 @@ obj-$(CONFIG_MTD_NAND_TMIO) += tmio_nand.o > obj-$(CONFIG_MTD_NAND_PLATFORM) += plat_nand.o > obj-$(CONFIG_MTD_NAND_PASEMI) += pasemi_nand.o > obj-$(CONFIG_MTD_NAND_ORION) += orion_nand.o > +obj-$(CONFIG_MTD_NAND_OXNAS) += oxnas_nand.o > obj-$(CONFIG_MTD_NAND_FSL_ELBC) += fsl_elbc_nand.o > obj-$(CONFIG_MTD_NAND_FSL_IFC) += fsl_ifc_nand.o > obj-$(CONFIG_MTD_NAND_FSL_UPM) += fsl_upm.o > diff --git a/drivers/mtd/nand/oxnas_nand.c b/drivers/mtd/nand/oxnas_nand.c > new file mode 100644 > index 0000000..ee402ab > --- /dev/null > +++ b/drivers/mtd/nand/oxnas_nand.c > @@ -0,0 +1,144 @@ > +/* > + * Oxford Semiconductor OXNAS NAND driver > + * > + * Heavily based on plat_nand.c : > + * Author: Vitaly Wool <vitalyw...@gmail.com> > + * > + * 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. > + * > + */ > + > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > +#include <linux/clk.h> > +#include <linux/reset.h> > +#include <linux/mtd/mtd.h> > +#include <linux/mtd/nand.h> > +#include <linux/mtd/partitions.h> > + > +/* nand commands */ > +#define NAND_CMD_ALE BIT(18) > +#define NAND_CMD_CLE BIT(19) > +#define NAND_CMD_CS 0 > +#define NAND_CMD_RESET 0xff > +#define NAND_CMD (NAND_CMD_CS | NAND_CMD_CLE) > +#define NAND_ADDR (NAND_CMD_CS | NAND_CMD_ALE) > +#define NAND_DATA (NAND_CMD_CS) > + > +struct oxnas_nand_data { > + struct nand_chip chip; > + void __iomem *io_base; Why do you redundantly keep io_base in platform data rather than just using chip.IO_ADDR_R and >chip.IO_ADDR_W? > + struct clk *clk; > +}; > + > +static void oxnas_nand_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; > + > + if (ctrl & NAND_CTRL_CHANGE) { > + nandaddr &= ~(NAND_CMD | NAND_ADDR); > + if (ctrl & NAND_CLE) > + nandaddr |= NAND_CMD; > + else if (ctrl & NAND_ALE) > + nandaddr |= NAND_ADDR; > + this->IO_ADDR_W = (void __iomem *) nandaddr; > + } > + > + if (cmd != NAND_CMD_NONE) > + writeb(cmd, (void __iomem *) nandaddr); > +} > + > +/* > + * Probe for the NAND device. > + */ > +static int oxnas_nand_probe(struct platform_device *pdev) > +{ > + struct oxnas_nand_data *data; > + struct mtd_info *mtd; > + struct resource *res; > + int err = 0; > + > + /* Allocate memory for the device structure (and zero it) */ > + data = devm_kzalloc(&pdev->dev, sizeof(struct oxnas_nand_data), > + GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + data->io_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(data->io_base)) > + return PTR_ERR(data->io_base); > + > + data->clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(data->clk)) > + data->clk = NULL; > + > + nand_set_flash_node(&data->chip, pdev->dev.of_node); > + mtd = nand_to_mtd(&data->chip); > + mtd->dev.parent = &pdev->dev; > + mtd->priv = &data->chip; > + > + data->chip.IO_ADDR_R = data->io_base; > + data->chip.IO_ADDR_W = data->io_base; > + data->chip.cmd_ctrl = oxnas_nand_cmd_ctrl; > + data->chip.chip_delay = 30; > + data->chip.ecc.mode = NAND_ECC_SOFT; > + data->chip.ecc.algo = NAND_ECC_HAMMING; > + > + platform_set_drvdata(pdev, data); > + > + clk_prepare_enable(data->clk); > + device_reset_optional(&pdev->dev); > + > + /* Scan to find existence of the device */ > + if (nand_scan(mtd, 1)) { > + err = -ENXIO; > + goto out; > + } > + > + err = mtd_device_parse_register(mtd, NULL, NULL, NULL, 0); > + if (!err) > + return err; > + > + nand_release(mtd); > +out: > + return err; > +} > + > +static int oxnas_nand_remove(struct platform_device *pdev) > +{ > + struct oxnas_nand_data *data = platform_get_drvdata(pdev); > + > + nand_release(nand_to_mtd(&data->chip)); > + > + return 0; > +} > + > +static const struct of_device_id oxnas_nand_match[] = { > + { .compatible = "oxsemi,ox820-nand" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, oxnas_nand_match); > + > +static struct platform_driver oxnas_nand_driver = { > + .probe = oxnas_nand_probe, > + .remove = oxnas_nand_remove, > + .driver = { > + .name = "oxnas_nand", > + .of_match_table = oxnas_nand_match, > + }, > +}; > + > +module_platform_driver(oxnas_nand_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Vitaly Wool"); > +MODULE_DESCRIPTION("Oxnas NAND driver"); > +MODULE_ALIAS("platform:oxnas_nand"); > -- > 2.7.0 > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
