[PATCH 1/4] mtd: nand: add NVIDIA Tegra NAND Flash controller driver
Lucas Stach
dev at lynxeye.de
Tue Jan 6 16:24:38 PST 2015
Am Dienstag, den 06.01.2015, 15:27 -0300 schrieb Ezequiel Garcia:
> On 01/04/2015 05:39 PM, Lucas Stach wrote:
>
> Hi Lucas,
>
> The driver looks mostly good. Just a few comments on my side.
>
> > Add support for the NAND flash controller found on NVIDIA
> > Tegra 2/3 SoCs. This is a largely reworked version of the driver
> > started by Thierry.
> >
> > Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
> > Signed-off-by: Lucas Stach <dev at lynxeye.de>
> > ---
> > I've tested this driver with the in-kernel mtd-tests and some
> > realworld workloads on a Colibri T20 module.
> > ---
> > .../bindings/mtd/nvidia,tegra20-nand.txt | 30 +
> > MAINTAINERS | 6 +
> > drivers/mtd/nand/Kconfig | 6 +
> > drivers/mtd/nand/Makefile | 1 +
> > drivers/mtd/nand/tegra_nand.c | 794 +++++++++++++++++++++
> > 5 files changed, 837 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > create mode 100644 drivers/mtd/nand/tegra_nand.c
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > new file mode 100644
> > index 0000000..088223c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > @@ -0,0 +1,30 @@
> > +NVIDIA Tegra NAND Flash controller
> > +
> > +Required properties:
> > +- compatible: Must be one of:
> > + - "nvidia,tegra20-nand"
> > + - "nvidia,tegra30-nand"
> > +- reg: MMIO address range
> > +- interrupts: interrupt output of the NFC controller
> > +- clocks: Must contain an entry for each entry in clock-names.
> > + See ../clocks/clock-bindings.txt for details.
> > +- clock-names: Must include the following entries:
> > + - nand
> > +- resets: Must contain an entry for each entry in reset-names.
> > + See ../reset/reset.txt for details.
> > +- reset-names: Must include the following entries:
> > + - nand
> > +
> > +Optional properties:
> > +- nvidia,wp-gpios: GPIO used to disable write protection of the flash
> > +
> > + Example:
> > + nand at 70008000 {
> > + compatible = "nvidia,tegra20-nand";
> > + reg = <0x70008000 0x100>;
> > + interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
> > + clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
> > + clock-names = "nand";
> > + resets = <&tegra_car 13>;
> > + reset-names = "nand";
> > + };
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index ddb9ac8..972e31d 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -9459,6 +9459,12 @@ M: Laxman Dewangan <ldewangan at nvidia.com>
> > S: Supported
> > F: drivers/input/keyboard/tegra-kbc.c
> >
> > +TEGRA NAND DRIVER
> > +M: Lucas Stach <dev at lynxeye.de>
> > +S: Maintained
> > +F: Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > +F: drivers/mtd/nand/tegra_nand.c
> > +
> > TEGRA PWM DRIVER
> > M: Thierry Reding <thierry.reding at gmail.com>
> > S: Supported
> > diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> > index 7d0150d..1eafd4e 100644
> > --- a/drivers/mtd/nand/Kconfig
> > +++ b/drivers/mtd/nand/Kconfig
> > @@ -524,4 +524,10 @@ config MTD_NAND_SUNXI
> > help
> > Enables support for NAND Flash chips on Allwinner SoCs.
> >
> > +config MTD_NAND_TEGRA
> > + tristate "Support for NAND on NVIDIA Tegra"
> > + depends on ARCH_TEGRA || COMPILE_TEST
> > + help
> > + Enables support for NAND flash on NVIDIA Tegra SoC based boards.
> > +
> > endif # MTD_NAND
> > diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> > index bd38f21..58399ce 100644
> > --- a/drivers/mtd/nand/Makefile
> > +++ b/drivers/mtd/nand/Makefile
> > @@ -51,5 +51,6 @@ obj-$(CONFIG_MTD_NAND_GPMI_NAND) += gpmi-nand/
> > obj-$(CONFIG_MTD_NAND_XWAY) += xway_nand.o
> > obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH) += bcm47xxnflash/
> > obj-$(CONFIG_MTD_NAND_SUNXI) += sunxi_nand.o
> > +obj-$(CONFIG_MTD_NAND_TEGRA) += tegra_nand.o
> >
> > nand-objs := nand_base.o nand_bbt.o nand_timings.o
> > diff --git a/drivers/mtd/nand/tegra_nand.c b/drivers/mtd/nand/tegra_nand.c
> > new file mode 100644
> > index 0000000..b919a6e
> > --- /dev/null
> > +++ b/drivers/mtd/nand/tegra_nand.c
> > @@ -0,0 +1,794 @@
> > +/*
> > + * Copyright (C) 2014-2015 Lucas Stach <dev at lynxeye.de>
> > + * Copyright (C) 2012 Avionic Design GmbH
> > + *
> > + * 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/clk.h>
> > +#include <linux/completion.h>
> > +#include <linux/delay.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/err.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/mtd/nand.h>
> > +#include <linux/mtd/partitions.h>
> > +#include <linux/of_gpio.h>
> > +#include <linux/of_mtd.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +
> > +#define CMD 0x00
> > +#define CMD_GO (1 << 31)
> > +#define CMD_CLE (1 << 30)
> > +#define CMD_ALE (1 << 29)
> > +#define CMD_PIO (1 << 28)
> > +#define CMD_TX (1 << 27)
> > +#define CMD_RX (1 << 26)
>
> How about using BIT() ?
>
> > +#define CMD_SEC_CMD (1 << 25)
> > +#define CMD_AFT_DAT (1 << 24)
> > +#define CMD_TRANS_SIZE(x) (((x) & 0xf) << 20)
> > +#define CMD_A_VALID (1 << 19)
> > +#define CMD_B_VALID (1 << 18)
> > +#define CMD_RD_STATUS_CHK (1 << 17)
> > +#define CMD_RBSY_CHK (1 << 16)
> > +#define CMD_CE(x) (1 << (8 + ((x) & 0x7)))
> > +#define CMD_CLE_SIZE(x) (((x) & 0x3) << 4)
> > +#define CMD_ALE_SIZE(x) (((x) & 0xf) << 0)
> > +
> > +#define STATUS 0x04
> > +
> > +#define ISR 0x08
> > +#define ISR_UND (1 << 7)
> > +#define ISR_OVR (1 << 6)
> > +#define ISR_CMD_DONE (1 << 5)
> > +#define ISR_ECC_ERR (1 << 4)
> > +
> > +#define IER 0x0c
> > +#define IER_ERR_TRIG_VAL(x) (((x) & 0xf) << 16)
> > +#define IER_UND (1 << 7)
> > +#define IER_OVR (1 << 6)
> > +#define IER_CMD_DONE (1 << 5)
> > +#define IER_ECC_ERR (1 << 4)
> > +#define IER_GIE (1 << 0)
> > +
> > +#define CFG 0x10
> > +#define CFG_HW_ECC (1 << 31)
> > +#define CFG_ECC_SEL (1 << 30)
> > +#define CFG_ERR_COR (1 << 29)
> > +#define CFG_PIPE_EN (1 << 28)
> > +#define CFG_TVAL_4 (0 << 24)
> > +#define CFG_TVAL_6 (1 << 24)
> > +#define CFG_TVAL_8 (2 << 24)
> > +#define CFG_SKIP_SPARE (1 << 23)
> > +#define CFG_BUS_WIDTH_8 (0 << 21)
> > +#define CFG_BUS_WIDTH_16 (1 << 21)
> > +#define CFG_COM_BSY (1 << 20)
> > +#define CFG_PS_256 (0 << 16)
> > +#define CFG_PS_512 (1 << 16)
> > +#define CFG_PS_1024 (2 << 16)
> > +#define CFG_PS_2048 (3 << 16)
> > +#define CFG_PS_4096 (4 << 16)
> > +#define CFG_SKIP_SPARE_SIZE_4 (0 << 14)
> > +#define CFG_SKIP_SPARE_SIZE_8 (1 << 14)
> > +#define CFG_SKIP_SPARE_SIZE_12 (2 << 14)
> > +#define CFG_SKIP_SPARE_SIZE_16 (3 << 14)
> > +#define CFG_TAG_BYTE_SIZE(x) ((x) & 0xff)
> > +
> > +#define TIMING_1 0x14
> > +#define TIMING_TRP_RESP(x) (((x) & 0xf) << 28)
> > +#define TIMING_TWB(x) (((x) & 0xf) << 24)
> > +#define TIMING_TCR_TAR_TRR(x) (((x) & 0xf) << 20)
> > +#define TIMING_TWHR(x) (((x) & 0xf) << 16)
> > +#define TIMING_TCS(x) (((x) & 0xc) << 14)
> > +#define TIMING_TWH(x) (((x) & 0x3) << 12)
> > +#define TIMING_TWP(x) (((x) & 0xf) << 8)
> > +#define TIMING_TRH(x) (((x) & 0xf) << 4)
> > +#define TIMING_TRP(x) (((x) & 0xf) << 0)
> > +
> > +#define RESP 0x18
> > +
> > +#define TIMING_2 0x1c
> > +#define TIMING_TADL(x) ((x) & 0xf)
> > +
> > +#define CMD_1 0x20
> > +#define CMD_2 0x24
> > +#define ADDR_1 0x28
> > +#define ADDR_2 0x2c
> > +
> > +#define DMA_CTRL 0x30
> > +#define DMA_CTRL_GO (1 << 31)
> > +#define DMA_CTRL_IN (0 << 30)
> > +#define DMA_CTRL_OUT (1 << 30)
> > +#define DMA_CTRL_PERF_EN (1 << 29)
> > +#define DMA_CTRL_IE_DONE (1 << 28)
> > +#define DMA_CTRL_REUSE (1 << 27)
> > +#define DMA_CTRL_BURST_1 (2 << 24)
> > +#define DMA_CTRL_BURST_4 (3 << 24)
> > +#define DMA_CTRL_BURST_8 (4 << 24)
> > +#define DMA_CTRL_BURST_16 (5 << 24)
> > +#define DMA_CTRL_IS_DONE (1 << 20)
> > +#define DMA_CTRL_EN_A (1 << 2)
> > +#define DMA_CTRL_EN_B (1 << 1)
> > +
> > +#define DMA_CFG_A 0x34
> > +#define DMA_CFG_B 0x38
> > +
> > +#define FIFO_CTRL 0x3c
> > +#define FIFO_CTRL_CLR_ALL (1 << 3)
> > +
> > +#define DATA_PTR 0x40
> > +#define TAG_PTR 0x44
> > +#define ECC_PTR 0x48
> > +
> > +#define HWSTATUS_CMD 0x50
> > +#define HWSTATUS_MASK 0x54
> > +#define HWSTATUS_RDSTATUS_MASK(x) (((x) & 0xff) << 24)
> > +#define HWSTATUS_RDSTATUS_VALUE(x) (((x) & 0xff) << 16)
> > +#define HWSTATUS_RBSY_MASK(x) (((x) & 0xff) << 8)
> > +#define HWSTATUS_RBSY_VALUE(x) (((x) & 0xff) << 0)
> > +
> > +#define DEC_RESULT 0xd0
> > +#define DEC_RESULT_CORRFAIL (1 << 8)
> > +
> > +#define DEC_STATUS_BUF 0xd4
> > +#define DEC_STATUS_BUF_FAIL_SEC_FLAG(x) ((x) & (0xff << 24))
> > +#define DEC_STATUS_BUF_CORR_SEC_FLAG(x) ((x) & (0xff << 16))
> > +#define DEC_STATUS_BUF_MAX_CORR_CNT(x) (((x) & 0xf00) >> 8)
> > +
> > +struct tegra_nand {
> > + void __iomem *regs;
> > + int irq;
>
> Seems like you don't need to store irq.
>
> > + struct clk *clk;
> > + struct reset_control *rst;
> > + int wp_gpio;
> > + int buswidth;
>
> And also you don't seem to need either wp_gpio or buswidth stored
> in the struct. You only use them at probe time.
>
I'll keep the wp_gpio, as I still hope to use this to WP the NAND when
no write is pending. I'll fix the others.
> > +
> > + struct nand_chip chip;
> > + struct mtd_info mtd;
> > + struct device *dev;
> > +
> > + struct completion command_complete;
> > + struct completion dma_complete;
> > +
> > + dma_addr_t data_dma;
> > + void *data_buf;
> > + dma_addr_t oob_dma;
> > + void *oob_buf;
> > +
> > + int cur_chip;
> > +};
[...]
> > +static int tegra_nand_parse_dt(struct device_node *node,
> > + struct tegra_nand *nand)
> > +{
> > + enum of_gpio_flags flags;
> > +
> > + nand->wp_gpio = of_get_named_gpio_flags(node, "nvidia,wp-gpios", 0,
> > + &flags);
> > + if (nand->wp_gpio < 0)
> > + nand->wp_gpio = 0;
> > +
> > + nand->buswidth = of_get_nand_bus_width(node);
> > + if (nand->buswidth < 0)
> > + return nand->buswidth;
> > +
>
> I believe you should set NAND_BUSWIDTH_16 flag in nand_chip.options,
> before calling nand_scan_ident?
>
> Also, if you just access the of_get_nand_bus_width before nand_scan_ident
> you can drop the nand->buswidth field.
>
> Same goes for wp_gpio.
>
Right, will do.
> > + return 0;
> > +}
> > +
[...]
> > +
> > +static const struct of_device_id tegra_nand_of_match[] = {
> > + { .compatible = "nvidia,tegra20-nand" },
> > + { .compatible = "nvidia,tegra30-nand" },
>
> AFAIK, having two compatible strings, but making no distinction between
> them is typically frowned upon by devicetree maintainers.
>
> Is the controller any different in tegra20 and tegra30?
>
> If you are not sure about the controllers being different, you can
> try the following approach. The devicetree is written like this:
>
> nand at foo {
> compatible = "nvidia,tegra20-nand", "nvidia,tegra-nand";
> };
>
> So you only deal with "nvidia,tegra-nand" in the driver, yet the
> devicetree files are prepared to deal with a difference.
>
I believe that tegra30-nand is actually a bit different from tegra20 (at
least on more clock I know about), but obviously this driver doesn't
handle those differences and I don't know if I ever get to see Tegra30
hardware with NAND. Given that I think it's best to just remove the
tegra30-nand compatible for now and add it back if someone has hardware
to test with.
Regards,
Lucas
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