On Mon, 2018-02-19 at 17:54 +1030, Joel Stanley wrote:
> The LPC device needs to ensure it's clock is enabled before it can do
> anything.
>
> In the past the clock was enabled and left running by u-boot, however
> Linux now has an upstream clock driver that disables unused clocks.
>
> Tested-by: Lei YU <mine260309@xxxxxxxxx>
> Reviewed-by: Andrew Jeffery <andrew@xxxxxxxx>
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
Reviewed-by: Cyril Bur <cyrilbur@xxxxxxxxx>
> ---
> drivers/misc/aspeed-lpc-ctrl.c | 26 +++++++++++++++++++++++---
> 1 file changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/misc/aspeed-lpc-ctrl.c b/drivers/misc/aspeed-lpc-ctrl.c
> index b5439643f54b..1827b7aa6674 100644
> --- a/drivers/misc/aspeed-lpc-ctrl.c
> +++ b/drivers/misc/aspeed-lpc-ctrl.c
> @@ -7,6 +7,7 @@
> * 2 of the License, or (at your option) any later version.
> */
>
> +#include <linux/clk.h>
> #include <linux/mfd/syscon.h>
> #include <linux/miscdevice.h>
> #include <linux/mm.h>
> @@ -26,6 +27,7 @@
> struct aspeed_lpc_ctrl {
> struct miscdevice miscdev;
> struct regmap *regmap;
> + struct clk *clk;
> phys_addr_t mem_base;
> resource_size_t mem_size;
> u32 pnor_size;
> @@ -221,16 +223,33 @@ static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + lpc_ctrl->clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(lpc_ctrl->clk)) {
> + dev_err(dev, "couldn't get clock\n");
> + return PTR_ERR(lpc_ctrl->clk);
> + }
> + rc = clk_prepare_enable(lpc_ctrl->clk);
> + if (rc) {
> + dev_err(dev, "couldn't enable clock\n");
> + return rc;
> + }
> +
> lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR;
> lpc_ctrl->miscdev.name = DEVICE_NAME;
> lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops;
> lpc_ctrl->miscdev.parent = dev;
> rc = misc_register(&lpc_ctrl->miscdev);
> - if (rc)
> + if (rc) {
> dev_err(dev, "Unable to register device\n");
> - else
> - dev_info(dev, "Loaded at %pr\n", &resm);
> + goto err;
> + }
> +
> + dev_info(dev, "Loaded at %pr\n", &resm);
> +
> + return 0;
>
> +err:
> + clk_disable_unprepare(lpc_ctrl->clk);
> return rc;
> }
>
> @@ -239,6 +258,7 @@ static int aspeed_lpc_ctrl_remove(struct platform_device *pdev)
> struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev);
>
> misc_deregister(&lpc_ctrl->miscdev);
> + clk_disable_unprepare(lpc_ctrl->clk);
>
> return 0;
> }
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