On Thu, Apr 30, 2020 at 02:56:57PM +0300, Priit Laes wrote:
> On sun7i, the gmac clock is handled by the dwmac-sunxi driver, but
> its configuration register is located in the CCU register range,
> requiring proper regmap setup.
>
> In order to do that, we use CLK_OF_DECLARE_DRIVER to initialize
> sun7i ccu, which clears the OF_POPULATED flag, allowing the
> platform device to probe the same resource with proper device node.
>
> Signed-off-by: Priit Laes <plaes@xxxxxxxxx>
> ---
> drivers/clk/sunxi-ng/ccu-sun4i-a10.c | 62 +++++++++++++++++++++++++++-
> 1 file changed, 60 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu-sun4i-a10.c b/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
> index f32366d9336e..fa147b8ce705 100644
> --- a/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
> +++ b/drivers/clk/sunxi-ng/ccu-sun4i-a10.c
> @@ -8,6 +8,8 @@
> #include <linux/clk-provider.h>
> #include <linux/io.h>
> #include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
>
> #include "ccu_common.h"
> #include "ccu_reset.h"
> @@ -1478,5 +1480,61 @@ static void __init sun7i_a20_ccu_setup(struct device_node *node)
> {
> sun4i_ccu_init(node, &sun7i_a20_ccu_desc);
> }
> -CLK_OF_DECLARE(sun7i_a20_ccu, "allwinner,sun7i-a20-ccu",
> - sun7i_a20_ccu_setup);
> +CLK_OF_DECLARE_DRIVER(sun7i_a20_ccu, "allwinner,sun7i-a20-ccu",
> + sun7i_a20_ccu_setup);
> +
> +/*
> + * Regmap for the GMAC driver (dwmac-sunxi) to allow access to
> + * GMAC configuration register.
> + */
> +#define SUN7I_A20_GMAC_CFG_REG 0x164
> +static bool sun7i_a20_ccu_regmap_accessible_reg(struct device *dev,
> + unsigned int reg)
> +{
> + if (reg == SUN7I_A20_GMAC_CFG_REG)
> + return true;
> + return false;
> +}
> +
> +static struct regmap_config sun7i_a20_ccu_regmap_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> + .max_register = 0x1f4, /* clk_out_b */
> +
> + .readable_reg = sun7i_a20_ccu_regmap_accessible_reg,
> + .writeable_reg = sun7i_a20_ccu_regmap_accessible_reg,
> +};
> +
> +static int sun7i_a20_ccu_probe_regmap(struct platform_device *pdev)
> +{
> + void __iomem *reg;
> + struct resource *res;
> + struct regmap *regmap;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> + if (IS_ERR(reg))
> + return PTR_ERR(reg);
You shouldn't really create a second mapping here but reuse the one you got in
sun7i_a20_ccu_setup, since that code expect to be the sole user of it.
Storing the virtual address in a global variable should work fine since we only
ever have a single instance of the controller
Maxime
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