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

Ladislav Michl
2017-11-15T10:54:25Z

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.

> > 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.

> > + 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.

> > - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > - if (res == NULL) {
> > - r = -EINVAL;
> > - dev_err(&pdev->dev, "error getting memory resource\n");
> > - goto err_kfree;
> > - }
> > + mem_size = resource_size(res);
> > + if (!devm_request_mem_region(dev, c->phys_base, mem_size,
> > + dev->driver->name)) {
> >
> > - c->phys_base = res->start;
> > - c->mem_size = resource_size(res);
> > -
> > - if (request_mem_region(c->phys_base, c->mem_size,
> > - pdev->dev.driver->name) == NULL) {
> > - dev_err(&pdev->dev, "Cannot reserve memory region at 0x%08lx, size: 0x%x\n",
> > - c->phys_base, c->mem_size);
> > - r = -EBUSY;
> > - goto err_kfree;
> > - }
> > - c->onenand.base = ioremap(c->phys_base, c->mem_size);
> > - if (c->onenand.base == NULL) {
> > - r = -ENOMEM;
> > - goto err_release_mem_region;
> > + dev_err(dev, "Cannot reserve memory region at 0x%08lx, size: 0x%x\n",
> > + c->phys_base, mem_size);
> > + return -EBUSY;
> > }
> >
> > - if (pdata->onenand_setup != NULL) {
> > - r = pdata->onenand_setup(c->onenand.base, &c->freq);
> > - if (r < 0) {
> > - dev_err(&pdev->dev, "Onenand platform setup failed: "
> > - "%d\n", r);
> > - goto err_iounmap;
> > - }
> > - c->setup = pdata->onenand_setup;
> > - }
> > + c->onenand.base = devm_ioremap(dev, c->phys_base, mem_size);
> > + if (!c->onenand.base)
> > + return -ENOMEM;
>
> How about doing request and ioremap in one shot?
>
> c->onenand.base = devm_ioremap_resource(&pdev->dev, res);
> if (IS_ERR(base))
> return PTR_ERR(base);

Good idea..

> >
> > - if (c->gpio_irq) {
> > - if ((r = gpio_request(c->gpio_irq, "OneNAND irq")) < 0) {
> > - dev_err(&pdev->dev, "Failed to request GPIO%d for "
> > - "OneNAND\n", c->gpio_irq);
> > - goto err_iounmap;
> > - }
> > - gpio_direction_input(c->gpio_irq);
> > + c->ready_gpiod = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
>
> I'd keep the name "onenand int" if it is the INT pin.

Ok.

> > + if (IS_ERR(c->ready_gpiod)) {
> > + r = PTR_ERR(c->ready_gpiod);
> > + /* Just try again if this happens */
> > + if (r != -EPROBE_DEFER)
> > + dev_err(dev, "error getting gpio: %d\n", r);
> > + return r;
> > + }
> >
> > - if ((r = request_irq(gpio_to_irq(c->gpio_irq),
> > - omap2_onenand_interrupt, IRQF_TRIGGER_RISING,
> > - pdev->dev.driver->name, c)) < 0)
> > - goto err_release_gpio;
> > + if (c->ready_gpiod) {
> > + r = devm_request_irq(dev, gpiod_to_irq(c->ready_gpiod),
> > + omap2_onenand_interrupt,
> > + IRQF_TRIGGER_RISING, "OneNAND", c);
>
> "onenand" to be consistent with onenand_base.c?

Ok.

> > + if (r)
> > + return r;
> >
> > - this->wait = omap2_onenand_wait;
> > + c->onenand.wait = omap2_onenand_wait;
> > }
> >
> > - if (pdata->dma_channel >= 0) {
> > - dma_cap_mask_t mask;
> > -
> > - dma_cap_zero(mask);
> > - dma_cap_set(DMA_MEMCPY, mask);
> > + dma_cap_zero(mask);
> > + dma_cap_set(DMA_MEMCPY, mask);
> >
> > - c->dma_chan = dma_request_channel(mask, NULL, NULL);
> > + c->dma_chan = dma_request_channel(mask, NULL, NULL);
> > + if (c->dma_chan) {
> > + c->onenand.read_bufferram = omap2_onenand_read_bufferram;
> > + c->onenand.write_bufferram = omap2_onenand_write_bufferram;
> > }
> >
> > - dev_info(&pdev->dev, "initializing on CS%d, phys base 0x%08lx, virtual "
> > - "base %p, freq %d MHz, %s mode\n", c->gpmc_cs, c->phys_base,
> > - c->onenand.base, c->freq, c->dma_chan ? "DMA" : "PIO");
> > -
> > c->pdev = pdev;
> > c->mtd.priv = &c->onenand;
> > + c->mtd.dev.parent = dev;
> > + mtd_set_of_node(&c->mtd, dev->of_node);
> >
> > - c->mtd.dev.parent = &pdev->dev;
> > - mtd_set_of_node(&c->mtd, pdata->of_node);
> > -
> > - this = &c->onenand;
> > - if (c->dma_chan) {
> > - this->read_bufferram = omap2_onenand_read_bufferram;
> > - this->write_bufferram = omap2_onenand_write_bufferram;
> > - }
> > + dev_info(dev, "initializing on CS%d (0x%08lx), va %p, %s mode\n",
> > + c->gpmc_cs, c->phys_base, c->onenand.base,
> > + c->dma_chan ? "DMA" : "PIO");
> >
> > if ((r = onenand_scan(&c->mtd, 1)) < 0)
> > goto err_release_dma;
> >
> > + freq = omap2_onenand_get_freq(c->onenand.version_id);
> > + if (freq > 0) {
> > + switch (freq) {
> > + case 104:
> > + latency = 7;
> > + break;
> > + case 83:
> > + latency = 6;
> > + break;
> > + case 66:
> > + latency = 5;
> > + break;
> > + case 56:
> > + latency = 4;
> > + break;
> > + default: /* 40 MHz or lower */
> > + latency = 3;
> > + break;
> > + }
> > +
> > + r = gpmc_omap_onenand_set_timings(dev, c->gpmc_cs,
> > + freq, latency, &info);
> > + if (r)
> > + goto err_release_onenand;
> > +
> > + r = omap2_onenand_set_cfg(c, info.sync_read, info.sync_write,
> > + latency, info.burst_len);
> > + if (r)
> > + goto err_release_onenand;
> > +
> > + if (info.sync_read || info.sync_write)
> > + dev_info(dev, "optimized timings for %d MHz\n", freq);
> > + }
> > +
> > r = mtd_device_register(&c->mtd, NULL, 0);
> > if (r)
> > goto err_release_onenand;
> > @@ -561,17 +632,6 @@ static int omap2_onenand_probe(struct platform_device *pdev)
> > err_release_dma:
> > if (c->dma_chan)
> > dma_release_channel(c->dma_chan);
> > - if (c->gpio_irq)
> > - free_irq(gpio_to_irq(c->gpio_irq), c);
> > -err_release_gpio:
> > - if (c->gpio_irq)
> > - gpio_free(c->gpio_irq);
> > -err_iounmap:
> > - iounmap(c->onenand.base);
> > -err_release_mem_region:
> > - release_mem_region(c->phys_base, c->mem_size);
> > -err_kfree:
> > - kfree(c);
> >
> > return r;
> > }
> > @@ -584,23 +644,23 @@ static int omap2_onenand_remove(struct platform_device *pdev)
> > if (c->dma_chan)
> > dma_release_channel(c->dma_chan);
> > omap2_onenand_shutdown(pdev);
> > - if (c->gpio_irq) {
> > - free_irq(gpio_to_irq(c->gpio_irq), c);
> > - gpio_free(c->gpio_irq);
> > - }
> > - iounmap(c->onenand.base);
> > - release_mem_region(c->phys_base, c->mem_size);
> > - kfree(c);
> >
> > return 0;
> > }
> >
> > +static const struct of_device_id omap2_onenand_id_table[] = {
> > + { .compatible = "ti,omap2-onenand", },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, omap2_onenand_id_table);
> > +
> > static struct platform_driver omap2_onenand_driver = {
> > .probe = omap2_onenand_probe,
> > .remove = omap2_onenand_remove,
> > .shutdown = omap2_onenand_shutdown,
> > .driver = {
> > .name = DRIVER_NAME,
> > + .of_match_table = omap2_onenand_id_table,
> > },
> > };
> >
> >
>
> --
> cheers,
> -roger
>
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