Re: [PATCH] mtd: atmel_nand: move the hsmc_clk from nfc node to nand node

From: Nicolas Ferre
Date: Mon Feb 22 2016 - 07:57:06 EST


Le 17/02/2016 06:40, Wenyou Yang a écrit :
> From: Josh Wu <josh.wu@xxxxxxxxx>
>
> For sama5d3, sama5d4 chip, the pmecc becomes a part of HSMC, they
> need the HSMC clock to be enabled to work.
> The NFC is a sub feature for current nand driver, it can be disabled.
> But if HSMC clock is controlled by NFC, so disable NFC will also
> disable the HSMC clock. then, it will make the PMECC fail to work.
>
> So the solution is to move the HSMC clock out of NFC to nand node.
> When nand driver probed, it will check whether the chip has HSMC,
> if yes then it will require a HSMC clock.
>
> Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> ---
>
> .../devicetree/bindings/mtd/atmel-nand.txt | 4 +-
> drivers/mtd/nand/atmel_nand.c | 43 +++++++++-----------
> 2 files changed, 22 insertions(+), 25 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> index d53aba9..29bee7c 100644
> --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> @@ -15,6 +15,7 @@ Required properties:
> - atmel,nand-cmd-offset : offset for the command latch.
> - #address-cells, #size-cells : Must be present if the device has sub-nodes
> representing partitions.
> +- clocks: phandle to the peripheral clock
>
> - gpios : specifies the gpio pins to control the NAND device. detect is an
> optional gpio and may be set to 0 if not present.
> @@ -43,7 +44,6 @@ Required properties:
> - reg : should specify the address and size used for NFC command registers,
> NFC registers and NFC SRAM. NFC SRAM address and size can be absent
> if don't want to use it.
> -- clocks: phandle to the peripheral clock
> Optional properties:
> - atmel,write-by-sram: boolean to enable NFC write by SRAM.
>
> @@ -100,13 +100,13 @@ nand0: nand@40000000 {
> compatible = "atmel,at91rm9200-nand";
> #address-cells = <1>;
> #size-cells = <1>;
> + clocks = <&hsmc_clk>
> ranges;
> ...
> nfc@70000000 {
> compatible = "atmel,sama5d3-nfc";
> #address-cells = <1>;
> #size-cells = <1>;
> - clocks = <&hsmc_clk>
> reg = <
> 0x70000000 0x10000000 /* NFC Command Registers */
> 0xffffc000 0x00000070 /* NFC HSMC regs */
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 20cbaab..a1f4ad2 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -66,6 +66,7 @@ module_param(on_flash_bbt, int, 0);
> struct atmel_nand_caps {
> bool pmecc_correct_erase_page;
> uint8_t pmecc_max_correction;
> + bool has_hsmc_clk;
> };
>
> struct atmel_nand_nfc_caps {
> @@ -106,8 +107,6 @@ struct atmel_nfc {
> bool use_nfc_sram;
> bool write_by_sram;
>
> - struct clk *clk;
> -
> bool is_initialized;
> struct completion comp_ready;
> struct completion comp_cmd_done;
> @@ -132,6 +131,7 @@ struct atmel_nand_host {
> struct dma_chan *dma_chan;
>
> struct atmel_nfc *nfc;
> + struct clk *clk;
>
> const struct atmel_nand_caps *caps;
> bool has_pmecc;
> @@ -2157,6 +2157,19 @@ static int atmel_nand_probe(struct platform_device *pdev)
> nand_chip->IO_ADDR_R = host->io_base;
> nand_chip->IO_ADDR_W = host->io_base;
>
> + if (host->caps->has_hsmc_clk) {
> + host->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(host->clk)) {
> + dev_err(&pdev->dev, "HSMC clock is missing, update your Device Tree");
> + res = PTR_ERR(host->clk);
> + goto err_nand_ioremap;
> + }
> +
> + res = clk_prepare_enable(host->clk);
> + if (res)
> + goto err_nand_ioremap;
> + }
> +
> if (nand_nfc.is_initialized) {
> /* NFC driver is probed and initialized */
> host->nfc = &nand_nfc;
> @@ -2321,6 +2334,9 @@ static int atmel_nand_remove(struct platform_device *pdev)
> if (host->dma_chan)
> dma_release_channel(host->dma_chan);
>
> + if (!IS_ERR(host->clk))
> + clk_disable_unprepare(host->clk);
> +
> platform_driver_unregister(&atmel_nand_nfc_driver);
>
> return 0;
> @@ -2334,11 +2350,13 @@ static int atmel_nand_remove(struct platform_device *pdev)
> static const struct atmel_nand_caps at91rm9200_caps = {
> .pmecc_correct_erase_page = false,
> .pmecc_max_correction = 24,
> + .has_hsmc_clk = false,
> };
>
> static const struct atmel_nand_caps sama5d4_caps = {
> .pmecc_correct_erase_page = true,
> .pmecc_max_correction = 24,
> + .has_hsmc_clk = true,

As this capability is not shared with SAMA5D3, I didn't see how you
could make the hsmc clock probed on SAMA5D3: remember, its controller
compatibility string is "atmel,at91rm9200-nand" with the description
just above.

Bye,


> };
>
> /*
> @@ -2363,7 +2381,6 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
> {
> struct atmel_nfc *nfc = &nand_nfc;
> struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
> - int ret;
>
> nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
> @@ -2401,31 +2418,12 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
> nfc_writel(nfc->hsmc_regs, IDR, 0xffffffff);
> nfc_readl(nfc->hsmc_regs, SR); /* clear the NFC_SR */
>
> - nfc->clk = devm_clk_get(&pdev->dev, NULL);
> - if (!IS_ERR(nfc->clk)) {
> - ret = clk_prepare_enable(nfc->clk);
> - if (ret)
> - return ret;
> - } else {
> - dev_warn(&pdev->dev, "NFC clock missing, update your Device Tree");
> - }
> -
> nfc->is_initialized = true;
> dev_info(&pdev->dev, "NFC is probed.\n");
>
> return 0;
> }
>
> -static int atmel_nand_nfc_remove(struct platform_device *pdev)
> -{
> - struct atmel_nfc *nfc = &nand_nfc;
> -
> - if (!IS_ERR(nfc->clk))
> - clk_disable_unprepare(nfc->clk);
> -
> - return 0;
> -}
> -
> static const struct atmel_nand_nfc_caps sama5d3_nfc_caps = {
> .rb_mask = NFC_SR_RB_EDGE0,
> };
> @@ -2447,7 +2445,6 @@ static struct platform_driver atmel_nand_nfc_driver = {
> .of_match_table = of_match_ptr(atmel_nand_nfc_match),
> },
> .probe = atmel_nand_nfc_probe,
> - .remove = atmel_nand_nfc_remove,
> };
>
> static struct platform_driver atmel_nand_driver = {
>


--
Nicolas Ferre