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    SubjectRe: [PATCH 07/12] memory: davinci-aemif: introduce AEMIF driver
    On 11/12/2013 06:08 PM, Santosh Shilimkar wrote:
    > + Greg KH (drivers/memory/* patches goes through his queue)
    >
    > On Monday 11 November 2013 12:06 PM, Khoronzhuk, Ivan wrote:
    >> Add new AEMIF driver for EMIF16 davinci controller. The EMIF16 module
    >> is intended to provide a glue-less interface to a variety of
    >> asynchronous memory devices like ASRA M, NOR and NAND memory. A total
    >> of 256M bytes of any of these memories can be accessed at any given
    >> time via four chip selects with 64M byte access per chip select.
    >>
    >> Synchronous memories such as DDR1 SD RAM, SDR SDRAM and Mobile SDR
    >> are not supported.
    >>
    >> See http://www.ti.com/lit/ug/sprugz3a/sprugz3a.pdf
    >>
    >> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
    >> ---
    >> drivers/memory/Kconfig | 11 ++
    >> drivers/memory/Makefile | 1 +
    >> drivers/memory/davinci-aemif.c | 415 ++++++++++++++++++++++++++++++++++++++++
    >> 3 files changed, 427 insertions(+)
    >> create mode 100644 drivers/memory/davinci-aemif.c
    >>
    >> diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
    >> index 29a11db..010e75e 100644
    >> --- a/drivers/memory/Kconfig
    >> +++ b/drivers/memory/Kconfig
    >> @@ -7,6 +7,17 @@ menuconfig MEMORY
    >>
    >> if MEMORY
    >>
    >> +config TI_DAVINCI_AEMIF
    > s/TI_DAVINCI_AEMIF/TI_AEMIF
    >

    Ok

    >> + bool "Texas Instruments DaVinci AEMIF driver"
    > Drop DaVinci above since its used on more SOCs.
    >> + depends on (ARCH_DAVINCI || ARCH_KEYSTONE) && OF
    >> + help
    >> + This driver is for the AEMIF module available in Texas Instruments
    >> + SoCs. AEMIF stands for Asynchronous External Memory Interface and
    >> + is intended to provide a glue-less interface to a variety of
    >> + asynchronuous memory devices like ASRAM, NOR and NAND memory. A total
    >> + of 256M bytes of any of these memories can be accessed at a given
    >> + time via four chip selects with 64M byte access per chip select.
    >> +
    >> config TI_EMIF
    >> tristate "Texas Instruments EMIF driver"
    >> depends on ARCH_OMAP2PLUS
    >> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
    >> index 969d923..af14126 100644
    >> --- a/drivers/memory/Makefile
    >> +++ b/drivers/memory/Makefile
    >> @@ -5,6 +5,7 @@
    >> ifeq ($(CONFIG_DDR),y)
    >> obj-$(CONFIG_OF) += of_memory.o
    >> endif
    >> +obj-$(CONFIG_TI_DAVINCI_AEMIF) += davinci-aemif.o
    >
    > Change this accordingly once the config is renamed.
    >

    Ok

    >> obj-$(CONFIG_TI_EMIF) += emif.o
    >> obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
    >> obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
    >> diff --git a/drivers/memory/davinci-aemif.c b/drivers/memory/davinci-aemif.c
    >> new file mode 100644
    >> index 0000000..e36b74b
    >> --- /dev/null
    >> +++ b/drivers/memory/davinci-aemif.c
    >> @@ -0,0 +1,415 @@
    >> +/*
    >> + * DaVinci/Keystone AEMIF driver
    > s/{DaVinci/Keystone}/TI
    >> + *
    >> + * Copyright (C) 2010 - 2013 Texas Instruments Incorporated. http://www.ti.com/
    >> + * Copyright (C) Heiko Schocher <hs@denx.de>
    >> + * Copyright (C) Ivan Khoronzhuk <ivan.khoronzhuk@ti.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/clk.h>
    >> +#include <linux/err.h>
    >> +#include <linux/io.h>
    >> +#include <linux/kernel.h>
    >> +#include <linux/module.h>
    >> +#include <linux/of.h>
    >> +#include <linux/of_platform.h>
    >> +#include <linux/platform_device.h>
    >> +
    >> +#define TA_SHIFT 2
    >> +#define RHOLD_SHIFT 4
    >> +#define RSTROBE_SHIFT 7
    >> +#define RSETUP_SHIFT 13
    >> +#define WHOLD_SHIFT 17
    >> +#define WSTROBE_SHIFT 20
    >> +#define WSETUP_SHIFT 26
    >> +#define EW_SHIFT 30
    >> +#define SS_SHIFT 31
    >> +
    >> +#define TA(x) ((x) << TA_SHIFT)
    >> +#define RHOLD(x) ((x) << RHOLD_SHIFT)
    >> +#define RSTROBE(x) ((x) << RSTROBE_SHIFT)
    >> +#define RSETUP(x) ((x) << RSETUP_SHIFT)
    >> +#define WHOLD(x) ((x) << WHOLD_SHIFT)
    >> +#define WSTROBE(x) ((x) << WSTROBE_SHIFT)
    >> +#define WSETUP(x) ((x) << WSETUP_SHIFT)
    >> +#define EW(x) ((x) << EW_SHIFT)
    >> +#define SS(x) ((x) << SS_SHIFT)
    >> +
    >> +#define ASIZE_MAX 0x1
    >> +#define TA_MAX 0x3
    >> +#define RHOLD_MAX 0x7
    >> +#define RSTROBE_MAX 0x3f
    >> +#define RSETUP_MAX 0xf
    >> +#define WHOLD_MAX 0x7
    >> +#define WSTROBE_MAX 0x3f
    >> +#define WSETUP_MAX 0xf
    >> +#define EW_MAX 0x1
    >> +#define SS_MAX 0x1
    >> +#define NUM_CS 4
    >> +
    >> +#define TA_VAL(x) (((x) & TA(TA_MAX)) >> TA_SHIFT)
    >> +#define RHOLD_VAL(x) (((x) & RHOLD(RHOLD_MAX)) >> RHOLD_SHIFT)
    >> +#define RSTROBE_VAL(x) (((x) & RSTROBE(RSTROBE_MAX)) >> RSTROBE_SHIFT)
    >> +#define RSETUP_VAL(x) (((x) & RSETUP(RSETUP_MAX)) >> RSETUP_SHIFT)
    >> +#define WHOLD_VAL(x) (((x) & WHOLD(WHOLD_MAX)) >> WHOLD_SHIFT)
    >> +#define WSTROBE_VAL(x) (((x) & WSTROBE(WSTROBE_MAX)) >> WSTROBE_SHIFT)
    >> +#define WSETUP_VAL(x) (((x) & WSETUP(WSETUP_MAX)) >> WSETUP_SHIFT)
    >> +#define EW_VAL(x) (((x) & EW(EW_MAX)) >> EW_SHIFT)
    >> +#define SS_VAL(x) (((x) & SS(SS_MAX)) >> SS_SHIFT)
    >> +
    >> +#define NRCSR_OFFSET 0x00
    >> +#define AWCCR_OFFSET 0x04
    >> +#define A1CR_OFFSET 0x10
    >> +
    >> +#define ACR_ASIZE_MASK 0x3
    >> +#define ACR_EW_MASK BIT(30)
    >> +#define ACR_SS_MASK BIT(31)
    >> +#define ASIZE_16BIT 1
    >> +
    >> +#define CONFIG_MASK (TA(TA_MAX) | \
    >> + RHOLD(RHOLD_MAX) | \
    >> + RSTROBE(RSTROBE_MAX) | \
    >> + RSETUP(RSETUP_MAX) | \
    >> + WHOLD(WHOLD_MAX) | \
    >> + WSTROBE(WSTROBE_MAX) | \
    >> + WSETUP(WSETUP_MAX) | \
    >> + EW(EW_MAX) | SS(SS_MAX) | \
    >> + ASIZE_MAX)
    >> +
    >> +#define DRV_NAME "davinci-aemif"
    > s/davinci-aemif/ti-aemif

    Ok

    >> +
    >> +/**
    >> + * structure to hold cs parameters
    >> + * @cs: chip-select number
    >> + * @wstrobe: write strobe width, ns
    >> + * @rstrobe: read strobe width, ns
    >> + * @wsetup: write setup width, ns
    >> + * @whold: write hold width, ns
    >> + * @rsetup: read setup width, ns
    >> + * @rhold: read hold width, ns
    >> + * @ta: minimum turn around time, ns
    >> + * @enable_ss: enable/disable select strobe mode
    >> + * @enable_ew: enable/disable extended wait mode
    >> + * @asize: width of the asynchronous device's data bus
    >> + */
    >> +struct davinci_aemif_cs_data {
    >> + u8 cs;
    >> + u16 wstrobe;
    >> + u16 rstrobe;
    >> + u8 wsetup;
    >> + u8 whold;
    >> + u8 rsetup;
    >> + u8 rhold;
    >> + u8 ta;
    >> + u8 enable_ss;
    >> + u8 enable_ew;
    >> + u8 asize;
    >> +};
    >> +
    > I suggest you drop davinci prefix throughout the
    > driver.
    >
    > [..]
    >

    Seems there is nothing to prevent
    Ok

    >> +static const struct of_device_id davinci_aemif_of_match[] = {
    >> + { .compatible = "ti,davinci-aemif", },
    >> + { .compatible = "ti,keystone-aemif", },
    >> + { .compatible = "ti,omap-L138-aemif", },
    >> + {},
    >> +};
    > Do we need three seperate compatible or "ti,aemif" should
    > be enough ? Are there differences which we need to handled
    > based on compatibles ?
    >

    We need separate compatibles. Depending on this cs start number is evaluated.
    For omap-L138-aemif it is 2 for keystone-aemif it is 0.

    >> +
    >> +static const struct of_device_id davinci_cs_of_match[] = {
    >> + { .compatible = "ti,davinci-cs", },
    >> + {},
    >> +};
    >> +
    >> +static int davinci_aemif_probe(struct platform_device *pdev)
    >> +{
    >> + int ret = -ENODEV, i;
    >> + struct resource *res;
    >> + struct device *dev = &pdev->dev;
    >> + struct device_node *np = dev->of_node;
    >> +
    >> + if (np == NULL)
    >> + return 0;
    >> +
    >> + if (aemif) {
    >> + dev_err(dev, "davinci_aemif driver is in use currently\n");
    >> + return -EBUSY;
    >> + }
    >> +
    >> + aemif = devm_kzalloc(dev, sizeof(*aemif), GFP_KERNEL);
    >> +
    > Drop this extra line.
    >

    Ok, I will

    >> + if (!aemif) {
    >> + dev_err(dev, "cannot allocate memory for aemif\n");
    >> + return -ENOMEM;
    >> + }
    >> +
    >> + aemif->clk = devm_clk_get(dev, "aemif");
    >> + if (IS_ERR(aemif->clk)) {
    >> + dev_err(dev, "cannot get clock 'aemif'\n");
    >> + return PTR_ERR(aemif->clk);
    >> + }
    >> +
    >> + clk_prepare_enable(aemif->clk);
    >> + aemif->clk_rate = clk_get_rate(aemif->clk) / 1000;
    >> +
    > 1000 divider ? Define a marco and use it to be clear.

    Is it OK if I use MSEC_PER_SEC (linux/time.h).

    >
    > Other than above comments patch looks fine to me.
    >
    > Regards,
    > Santosh
    >


    --
    Regards,
    Ivan Khoronzhuk


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