Re: [PATCH v4 14/16] mtd: onenand: omap2: Configure driver from DT

Roger Quadros
2017-11-15T11:05:01Z

On 15/11/17 12:53, Ladislav Michl wrote:
> On Wed, Nov 15, 2017 at 12:40:14PM +0200, Roger Quadros wrote:
>> On 11/11/17 23:27, Ladislav Michl wrote:
>>> Move away from platform data configuration and use pure DT approach.
>>>
>>> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
>>> ---
>>> Changes:
>>> -v2: move cleanups into separate patches
>>> simplify dma setup
>>> fix checkpatch error
>>> print info about otimized timings in sync mode only
>>> -v3: remove 'ti,omap3-onenand' compatible as it is not needed anymore
>>> -v4: none
>>>
>>> drivers/mtd/onenand/omap2.c | 264 +++++++++++++++++++++++++++-----------------
>>> 1 file changed, 162 insertions(+), 102 deletions(-)
>>>
>>> diff --git a/drivers/mtd/onenand/omap2.c b/drivers/mtd/onenand/omap2.c
>>> index 62e4ede918c4..9ebbbf297993 100644
>>> --- a/drivers/mtd/onenand/omap2.c
>>> +++ b/drivers/mtd/onenand/omap2.c
>>> @@ -28,6 +28,8 @@
>>> #include <linux/mtd/mtd.h>
>>> #include <linux/mtd/onenand.h>
>>> #include <linux/mtd/partitions.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/omap-gpmc.h>
>>> #include <linux/platform_device.h>
>>> #include <linux/interrupt.h>
>>> #include <linux/delay.h>
>>> @@ -35,10 +37,9 @@
>>> #include <linux/dmaengine.h>
>>> #include <linux/io.h>
>>> #include <linux/slab.h>
>>> -#include <linux/gpio.h>
>>> +#include <linux/gpio/consumer.h>
>>>
>>> #include <asm/mach/flash.h>
>>> -#include <linux/platform_data/mtd-onenand-omap2.h>
>>>
>>> #define DRIVER_NAME "omap2-onenand"
>>>
>>> @@ -48,15 +49,12 @@ struct omap2_onenand {
>>> struct platform_device *pdev;
>>> int gpmc_cs;
>>> unsigned long phys_base;
>>> - unsigned int mem_size;
>>> - int gpio_irq;
>>> + struct gpio_desc *ready_gpiod;
>>
>> Is this the RDY pin or the INT pin?
>> If it is the INT pin then I'd keep the name as int_gpiod.
>
> It is INT pin, so I'll use int_gpiod. Also shall we use int-gpios
> DT bindings then? Note, there can be two DPP devices in one die.

Yes int-gpios is better.
We'll leave the more than one devices case to be implemented whenever
someone has a real device.

>
>>> struct mtd_info mtd;
>>> struct onenand_chip onenand;
>>> struct completion irq_done;
>>> struct completion dma_done;
>>> struct dma_chan *dma_chan;
>>> - int freq;
>>> - int (*setup)(void __iomem *base, int *freq_ptr);
>>> };
>>>
>>> static void omap2_onenand_dma_complete_func(void *completion)
>>> @@ -84,6 +82,65 @@ static inline void write_reg(struct omap2_onenand *c, unsigned short value,
>>> writew(value, c->onenand.base + reg);
>>> }
>>>
>>> +static int omap2_onenand_set_cfg(struct omap2_onenand *c,
>>> + bool sr, bool sw,
>>> + int latency, int burst_len)
>>> +{
>>> + unsigned short reg = ONENAND_SYS_CFG1_RDY | ONENAND_SYS_CFG1_INT;
>>> +
>>> + reg |= latency << ONENAND_SYS_CFG1_BRL_SHIFT;
>>> +
>>> + switch (burst_len) {
>>> + case 0: /* continuous */
>>> + break;
>>> + case 4:
>>> + reg |= ONENAND_SYS_CFG1_BL_4;
>>> + break;
>>> + case 8:
>>> + reg |= ONENAND_SYS_CFG1_BL_8;
>>> + break;
>>> + case 16:
>>> + reg |= ONENAND_SYS_CFG1_BL_16;
>>> + break;
>>> + case 32:
>>> + reg |= ONENAND_SYS_CFG1_BL_32;
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (latency > 5)
>>> + reg |= ONENAND_SYS_CFG1_HF;
>>> + if (latency > 7)
>>> + reg |= ONENAND_SYS_CFG1_VHF;
>>> + if (sr)
>>> + reg |= ONENAND_SYS_CFG1_SYNC_READ;
>>> + if (sw)
>>> + reg |= ONENAND_SYS_CFG1_SYNC_WRITE;
>>> +
>>> + write_reg(c, reg, ONENAND_REG_SYS_CFG1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int omap2_onenand_get_freq(int ver)
>>> +{
>>> + switch ((ver >> 4) & 0xf) {
>>> + case 0:
>>> + return 40;
>>> + case 1:
>>> + return 54;
>>> + case 2:
>>> + return 66;
>>> + case 3:
>>> + return 83;
>>> + case 4:
>>> + return 104;
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> static void wait_err(char *msg, int state, unsigned int ctrl, unsigned int intr)
>>> {
>>> printk(KERN_ERR "onenand_wait: %s! state %d ctrl 0x%04x intr 0x%04x\n",
>>> @@ -152,12 +209,12 @@ static int omap2_onenand_wait(struct mtd_info *mtd, int state)
>>> }
>>>
>>> reinit_completion(&c->irq_done);
>>> - result = gpio_get_value(c->gpio_irq);
>>> + result = gpiod_get_value(c->ready_gpiod);
>>> if (result < 0) {
>>> ctrl = read_reg(c, ONENAND_REG_CTRL_STATUS);
>>> intr = read_reg(c, ONENAND_REG_INTERRUPT);
>>> wait_err("gpio error", state, ctrl, intr);
>>> - return -EIO;
>>> + return result;
>>> } else if (result == 0) {
>>> int retry_cnt = 0;
>>> retry:
>>> @@ -431,8 +488,6 @@ static int omap2_onenand_write_bufferram(struct mtd_info *mtd, int area,
>>> return 0;
>>> }
>>>
>>> -static struct platform_driver omap2_onenand_driver;
>>> -
>>> static void omap2_onenand_shutdown(struct platform_device *pdev)
>>> {
>>> struct omap2_onenand *c = dev_get_drvdata(&pdev->dev);
>>> @@ -446,108 +501,124 @@ static void omap2_onenand_shutdown(struct platform_device *pdev)
>>>
>>> static int omap2_onenand_probe(struct platform_device *pdev)
>>> {
>>> - struct omap_onenand_platform_data *pdata;
>>> - struct omap2_onenand *c;
>>> - struct onenand_chip *this;
>>> - int r;
>>> + u32 val;
>>> + dma_cap_mask_t mask;
>>> + int freq, latency, r;
>>> + unsigned int mem_size;
>>> struct resource *res;
>>> + struct omap2_onenand *c;
>>> + struct gpmc_onenand_info info;
>>> + struct device *dev = &pdev->dev;
>>> + struct device_node *np = dev->of_node;
>>>
>>> - pdata = dev_get_platdata(&pdev->dev);
>>> - if (pdata == NULL) {
>>> - dev_err(&pdev->dev, "platform data missing\n");
>>> - return -ENODEV;
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + if (!res) {
>>> + dev_err(dev, "error getting memory resource\n");
>>> + return -EINVAL;
>>> }
>>>
>>> - c = kzalloc(sizeof(struct omap2_onenand), GFP_KERNEL);
>>
>> We should error out if np is NULL before beginning to read DT properties?
>
> of_property_read_u32 will fail then, so I do not think it is worth adding
> explicit test for NULL here.
>

But the error message would be wrong in that case.
I'm trying to tackle the case where driver was probed using legacy methods
where device tree/node isn't present.

>>> + r = of_property_read_u32(np, "reg", &val);
>>> + if (r) {
>>> + dev_err(dev, "reg not found in DT\n");
>>> + return r;
>>> + }
>>> +
>>> + c = devm_kzalloc(dev, sizeof(struct omap2_onenand), GFP_KERNEL);
>>> if (!c)
>>> return -ENOMEM;
>>>
>>> init_completion(&c->irq_done);
>>> init_completion(&c->dma_done);
>>> - c->gpmc_cs = pdata->cs;
>>> - c->gpio_irq = pdata->gpio_irq;
>>> - if (pdata->dma_channel < 0) {
>>> - /* if -1, don't use DMA */
>>> - c->gpio_irq = 0;
>>> - }
>>> + c->gpmc_cs = val;
>>> + c->phys_base = res->start;
>>
>> Above 2 lines could be moved to just after where val and res is found respectively.
>
> Nope, we do not have 'c' allocated at that time.
>
indeed. silly me :)

>>> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

<snip>

--
cheers,
-roger

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