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

[Nicolas Ferre]

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