From: Roger Quadros <rogerq@ti.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: <tony@atomide.com>, <dwmw2@infradead.org>,
<ezequiel@vanguardiasur.com.ar>, <javier@dowhile0.org>,
<fcooper@ti.com>, <nsekhar@ti.com>,
<linux-mtd@lists.infradead.org>, <linux-omap@vger.kernel.org>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Boris Brezillon <boris.brezillon@free-electrons.com>,
Alex Smith <alex.smith@imgtec.com>,
Harvey Hunt <harvey.hunt@imgtec.com>
Subject: Re: [PATCH v3 18/27] mtd: nand: omap2: Implement NAND ready using gpiolib
Date: Tue, 27 Oct 2015 10:03:02 +0200 [thread overview]
Message-ID: <562F2FB6.7050806@ti.com> (raw)
In-Reply-To: <20151026204900.GI13239@google.com>
On 26/10/15 22:49, Brian Norris wrote:
> + others
>
> A few comments below.
>
> On Fri, Sep 18, 2015 at 05:53:40PM +0300, Roger Quadros wrote:
>> The GPMC WAIT pin status are now available over gpiolib.
>> Update the omap_dev_ready() function to use gpio instead of
>> directly accessing GPMC register space.
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>> drivers/mtd/nand/omap2.c | 29 +++++++++++++++++-----------
>> include/linux/platform_data/mtd-nand-omap2.h | 2 +-
>> 2 files changed, 19 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
>> index 228f498..d0f2620 100644
>> --- a/drivers/mtd/nand/omap2.c
>> +++ b/drivers/mtd/nand/omap2.c
>> @@ -12,6 +12,7 @@
>> #include <linux/dmaengine.h>
>> #include <linux/dma-mapping.h>
>> #include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>> #include <linux/module.h>
>> #include <linux/interrupt.h>
>> #include <linux/jiffies.h>
>> @@ -184,6 +185,8 @@ struct omap_nand_info {
>> /* fields specific for BCHx_HW ECC scheme */
>> struct device *elm_dev;
>> struct device_node *of_node;
>> + /* NAND ready gpio */
>> + struct gpio_desc *ready_gpiod;
>> };
>>
>> /**
>> @@ -1047,22 +1050,17 @@ static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
>> }
>>
>> /**
>> - * omap_dev_ready - calls the platform specific dev_ready function
>> + * omap_dev_ready - checks the NAND Ready GPIO line
>> * @mtd: MTD device structure
>> + *
>> + * Returns true if ready and false if busy.
>> */
>> static int omap_dev_ready(struct mtd_info *mtd)
>> {
>> - unsigned int val = 0;
>> struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
>> mtd);
>>
>> - val = readl(info->reg.gpmc_status);
>> -
>> - if ((val & 0x100) == 0x100) {
>> - return 1;
>> - } else {
>> - return 0;
>> - }
>> + return gpiod_get_value(info->ready_gpiod);
>> }
>>
>> /**
>> @@ -1782,7 +1780,9 @@ static int omap_nand_probe(struct platform_device *pdev)
>> info->reg = pdata->reg;
>> info->of_node = pdata->of_node;
>> info->ecc_opt = pdata->ecc_opt;
>> - info->dev_ready = pdata->dev_ready;
>> + if (pdata->dev_ready)
>> + dev_info(&pdev->dev, "pdata->dev_ready is deprecated\n");
>> +
>> info->xfer_type = pdata->xfer_type;
>> info->devsize = pdata->devsize;
>> info->elm_of_node = pdata->elm_of_node;
>> @@ -1815,6 +1815,13 @@ static int omap_nand_probe(struct platform_device *pdev)
>> nand_chip->IO_ADDR_W = nand_chip->IO_ADDR_R;
>> nand_chip->cmd_ctrl = omap_hwcontrol;
>>
>> + info->ready_gpiod = devm_gpiod_get_optional(&pdev->dev, "ready",
>> + GPIOD_IN);
>
> Others have been looking at using GPIOs for the ready/busy pin too. At a
> minimum, we need an updated DT binding doc for this, since I see you're
> adding this via device tree in a later patch (I don't see any DT binding
> patch for this; but I could just be overlooking it). It'd also be great
> if this support was moved to nand_dt_init() so other platforms can
> benefit, but I won't require that.
>
> Also, previous [0] proposers had suggested 'rb-gpios', not 'ready-gpio'
> (the hardware docs typically call it 'rb' for ready/busy, FWIW). I don't
> really care, but the name should be going into a doc, so we can choose
> the same one everywhere.
>
> EDIT: looks like the discussion was partly here [1] and it seems we're
> landing on "rb-gpios" in the latest version [2]. Can we stick with that?
Why should it be "rb-gpios" and not "rb-gpio"?
I don't think there are multiple gpios for r/b# function.
cheers,
-roger
>
> Regards,
> Brian
>
> [0] "Previous" may be subject to debate, as both series have been going
> for several revisions.
> [1] http://patchwork.ozlabs.org/patch/515327/
> [2] http://patchwork.ozlabs.org/patch/526819/
>
>> + if (IS_ERR(info->ready_gpiod)) {
>> + dev_err(dev, "failed to get ready gpio\n");
>> + return PTR_ERR(info->ready_gpiod);
>> + }
>> +
>> /*
>> * If RDY/BSY line is connected to OMAP then use the omap ready
>> * function and the generic nand_wait function which reads the status
>> @@ -1822,7 +1829,7 @@ static int omap_nand_probe(struct platform_device *pdev)
>> * chip delay which is slightly more than tR (AC Timing) of the NAND
>> * device and read status register until you get a failure or success
>> */
>> - if (info->dev_ready) {
>> + if (info->ready_gpiod) {
>> nand_chip->dev_ready = omap_dev_ready;
>> nand_chip->chip_delay = 0;
>> } else {
>> diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
>> index ff27e5a..19e509d 100644
>> --- a/include/linux/platform_data/mtd-nand-omap2.h
>> +++ b/include/linux/platform_data/mtd-nand-omap2.h
>> @@ -70,7 +70,6 @@ struct omap_nand_platform_data {
>> int cs;
>> struct mtd_partition *parts;
>> int nr_parts;
>> - bool dev_ready;
>> bool flash_bbt;
>> enum nand_io xfer_type;
>> int devsize;
>> @@ -81,5 +80,6 @@ struct omap_nand_platform_data {
>> /* deprecated */
>> struct gpmc_nand_regs reg;
>> struct device_node *of_node;
>> + bool dev_ready;
>> };
>> #endif
>> --
>> 2.1.4
>>
next prev parent reply other threads:[~2015-10-27 8:04 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-18 14:53 [PATCH v3 00/27] memory: omap-gpmc: mtd: nand: Support GPMC NAND on non-OMAP platforms Roger Quadros
2015-09-18 14:53 ` [PATCH v3 01/27] ARM: OMAP2+: gpmc: Add platform data Roger Quadros
2015-09-18 14:53 ` [PATCH v3 02/27] ARM: OMAP2+: gpmc: Add gpmc timings and settings to " Roger Quadros
2015-09-18 14:53 ` [PATCH v3 03/27] memory: omap-gpmc: Introduce GPMC to NAND interface Roger Quadros
2015-09-18 14:53 ` [PATCH v3 04/27] mtd: nand: omap2: Use gpmc_omap_get_nand_ops() to get NAND registers Roger Quadros
2015-12-03 5:00 ` Brian Norris
2015-09-18 14:53 ` [PATCH v3 05/27] memory: omap-gpmc: Add GPMC-NAND ops to get writebufferempty status Roger Quadros
2015-09-18 14:53 ` [PATCH v3 06/27] mtd: nand: omap2: Switch to using GPMC-NAND ops for writebuffer empty check Roger Quadros
2015-09-18 14:53 ` [PATCH v3 07/27] memory: omap-gpmc: Remove NAND IRQ code Roger Quadros
2015-09-18 14:53 ` [PATCH v3 08/27] memory: omap-gpmc: Add IRQ ops for GPMC-NAND interface Roger Quadros
2015-09-18 14:53 ` [PATCH v3 09/27] mtd: nand: omap2: manage NAND interrupts Roger Quadros
2015-09-18 14:53 ` [PATCH v3 10/27] mtd: nand: omap: Copy platform data parameters to omap_nand_info data Roger Quadros
2015-09-18 14:53 ` [PATCH v3 11/27] mtd: nand: omap: Clean up device tree support Roger Quadros
2015-10-06 10:35 ` [PATCH v4 " Roger Quadros
2015-12-03 4:29 ` Brian Norris
2015-12-03 5:57 ` Roger Quadros
2015-12-03 6:09 ` Brian Norris
2015-09-18 14:53 ` [PATCH v3 12/27] mtd: nand: omap: Update DT binding documentation Roger Quadros
2015-09-18 14:53 ` [PATCH v3 13/27] memory: omap-gpmc: Prevent mapping into 1st 16MB Roger Quadros
2015-09-18 14:53 ` [PATCH v3 14/27] memory: omap-gpmc: Move device tree binding to correct location Roger Quadros
2015-09-18 14:53 ` [PATCH v3 15/27] memory: omap-gpmc: Support general purpose input for WAITPINs Roger Quadros
2015-09-18 14:53 ` [PATCH v3 16/27] memory: omap-gpmc: Reserve WAITPIN if needed for WAIT monitoring Roger Quadros
2015-09-18 14:53 ` [PATCH v3 17/27] memory: omap-gpmc: Add irqchip support to the gpiochip Roger Quadros
2015-09-18 14:53 ` [PATCH v3 18/27] mtd: nand: omap2: Implement NAND ready using gpiolib Roger Quadros
2015-10-26 20:49 ` Brian Norris
2015-10-27 8:03 ` Roger Quadros [this message]
2015-10-27 8:12 ` Boris Brezillon
2015-10-27 8:43 ` Roger Quadros
2015-10-27 8:28 ` Boris Brezillon
2015-12-03 4:45 ` Brian Norris
2015-12-03 8:41 ` Boris Brezillon
2015-09-18 14:53 ` [PATCH v3 19/27] memory: omap-gpmc: Prevent GPMC_STATUS from being accessed via gpmc_regs Roger Quadros
2015-09-18 14:53 ` [PATCH v3 20/27] ARM: dts: dra7: Fix NAND device nodes Roger Quadros
2015-10-14 13:34 ` Franklin S Cooper Jr.
2015-10-14 14:17 ` Roger Quadros
2015-10-14 14:37 ` Franklin S Cooper Jr.
2015-09-18 14:53 ` [PATCH v3 21/27] ARM: dts: dra7x-evm: Provide NAND ready pin Roger Quadros
2015-09-18 14:53 ` [PATCH v3 22/27] ARM: dts: am437x: Fix NAND device nodes Roger Quadros
2015-09-18 14:53 ` [PATCH v3 23/27] ARM: dts: am437x-gp-evm: Provide NAND ready pin Roger Quadros
2015-09-18 14:53 ` [PATCH v3 24/27] ARM: dts: am335x: Fix NAND device nodes Roger Quadros
2015-09-18 14:53 ` [PATCH v3 25/27] ARM: dts: am335x: Provide NAND ready pin Roger Quadros
2015-09-18 14:53 ` [PATCH v3 26/27] ARM: dts: dm816x: Fix gpmc and NAND node Roger Quadros
2015-09-18 14:53 ` [PATCH v3 27/27] ARM: dts: omap3: Fix gpmc and NAND nodes Roger Quadros
2015-10-13 0:43 ` Tony Lindgren
2015-10-13 6:29 ` Roger Quadros
2015-10-13 15:18 ` Tony Lindgren
2015-10-14 7:39 ` Roger Quadros
2015-10-14 8:55 ` [PATCH v4 " Roger Quadros
2015-09-30 7:39 ` [PATCH v3 00/27] memory: omap-gpmc: mtd: nand: Support GPMC NAND on non-OMAP platforms Roger Quadros
2015-09-30 11:00 ` Roger Quadros
2015-10-06 8:33 ` Tony Lindgren
2015-10-06 9:54 ` Roger Quadros
2015-10-06 10:00 ` Tony Lindgren
2015-10-06 10:05 ` Roger Quadros
2015-10-06 10:28 ` Roger Quadros
2015-10-06 11:01 ` Tony Lindgren
2015-10-06 11:09 ` Roger Quadros
2015-10-16 21:25 ` Tony Lindgren
2015-10-19 7:08 ` Roger Quadros
2015-10-21 8:31 ` Roger Quadros
2015-10-21 15:20 ` Tony Lindgren
2015-10-23 7:09 ` Roger Quadros
2015-11-30 17:26 ` Tony Lindgren
2015-10-26 21:23 ` Brian Norris
2015-10-27 9:37 ` Roger Quadros
2015-11-25 10:42 ` Roger Quadros
2015-11-30 19:54 ` Brian Norris
2015-12-01 14:41 ` Roger Quadros
2015-12-02 3:26 ` Brian Norris
2015-12-02 5:12 ` Roger Quadros
2015-12-02 15:03 ` Tony Lindgren
2015-12-02 18:13 ` Brian Norris
2015-12-02 20:05 ` Tony Lindgren
2015-12-02 18:43 ` Brian Norris
2015-12-03 5:09 ` Brian Norris
2015-12-03 6:08 ` Roger Quadros
2015-12-03 6:22 ` Brian Norris
2015-12-03 9:01 ` Roger Quadros
2015-12-03 15:17 ` Tony Lindgren
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