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

Roger Quadros
2017-11-15T10:40:52Z

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.

> 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?

> + 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.

>
> - 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);

>
> - 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.

> + 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?

> + 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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