On Thu, Jun 18, 2020 at 02:11:39PM +0200, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx>
>
> At least VSC8530/8531/8540/8541 contain a clock output that can emit
> a predefined rate of 25, 50 or 125MHz.
>
> This may then feed back into the network interface as source clock.
> So expose a clock-provider from the phy using the common clock framework
> to allow setting the rate.
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/phy/mscc/mscc.h | 13 +++
> drivers/net/phy/mscc/mscc_main.c | 182 +++++++++++++++++++++++++++++--
> 2 files changed, 187 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
> index fbcee5fce7b2..94883dab5cc1 100644
> --- a/drivers/net/phy/mscc/mscc.h
> +++ b/drivers/net/phy/mscc/mscc.h
> @@ -218,6 +218,13 @@ enum rgmii_clock_delay {
> #define INT_MEM_DATA_M 0x00ff
> #define INT_MEM_DATA(x) (INT_MEM_DATA_M & (x))
>
> +#define MSCC_CLKOUT_CNTL 13
> +#define CLKOUT_ENABLE BIT(15)
> +#define CLKOUT_FREQ_MASK GENMASK(14, 13)
> +#define CLKOUT_FREQ_25M (0x0 << 13)
> +#define CLKOUT_FREQ_50M (0x1 << 13)
> +#define CLKOUT_FREQ_125M (0x2 << 13)
> +
> #define MSCC_PHY_PROC_CMD 18
> #define PROC_CMD_NCOMPLETED 0x8000
> #define PROC_CMD_FAILED 0x4000
> @@ -360,6 +367,12 @@ struct vsc8531_private {
> */
> unsigned int base_addr;
>
> +#ifdef CONFIG_COMMON_CLK
> + struct clk_hw clkout_hw;
> +#endif
> + u32 clkout_rate;
> + int clkout_enabled;
> +
> #if IS_ENABLED(CONFIG_MACSEC)
> /* MACsec fields:
> * - One SecY per device (enforced at the s/w implementation level)
> diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
> index 5d2777522fb4..727a9dd58403 100644
> --- a/drivers/net/phy/mscc/mscc_main.c
> +++ b/drivers/net/phy/mscc/mscc_main.c
> @@ -7,6 +7,7 @@
> * Copyright (c) 2016 Microsemi Corporation
> */
>
> +#include <linux/clk-provider.h>
> #include <linux/firmware.h>
> #include <linux/jiffies.h>
> #include <linux/kernel.h>
> @@ -431,7 +432,6 @@ static int vsc85xx_dt_led_mode_get(struct phy_device *phydev,
>
> return led_mode;
> }
> -
> #else
> static int vsc85xx_edge_rate_magic_get(struct phy_device *phydev)
> {
> @@ -1508,6 +1508,43 @@ static int vsc85xx_config_init(struct phy_device *phydev)
> return 0;
> }
>
> +static int vsc8531_config_init(struct phy_device *phydev)
> +{
> + struct vsc8531_private *vsc8531 = phydev->priv;
> + u16 val;
> + int rc;
> +
> + rc = vsc85xx_config_init(phydev);
> + if (rc)
> + return rc;
> +
> +#ifdef CONFIG_COMMON_CLK
> + switch (vsc8531->clkout_rate) {
> + case 25000000:
> + val = CLKOUT_FREQ_25M;
> + break;
> + case 50000000:
> + val = CLKOUT_FREQ_50M;
> + break;
> + case 125000000:
> + val = CLKOUT_FREQ_125M;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (vsc8531->clkout_enabled)
> + val |= CLKOUT_ENABLE;
> +
> + rc = phy_write_paged(phydev, MSCC_PHY_PAGE_EXTENDED_GPIO,
> + MSCC_CLKOUT_CNTL, val);
> + if (rc)
> + return rc;
> +#endif
> +
> + return 0;
> +}
> +
> +static int vsc8531_clkout_prepare(struct clk_hw *hw)
> +{
> + struct vsc8531_private *vsc8531 = clkout_hw_to_vsc8531(hw);
> +
> + vsc8531->clkout_enabled = true;
> + return 0;
> +}
> +
> +static void vsc8531_clkout_unprepare(struct clk_hw *hw)
> +{
> + struct vsc8531_private *vsc8531 = clkout_hw_to_vsc8531(hw);
> +
> + vsc8531->clkout_enabled = false;
> +}
> +
> +static const struct clk_ops vsc8531_clkout_ops = {
> + .prepare = vsc8531_clkout_prepare,
> + .unprepare = vsc8531_clkout_unprepare,
> + .is_prepared = vsc8531_clkout_is_prepared,
> + .recalc_rate = vsc8531_clkout_recalc_rate,
> + .round_rate = vsc8531_clkout_round_rate,
> + .set_rate = vsc8531_clkout_set_rate,
I'm not sure this is the expected behaviour. The clk itself should
only start ticking when the enable callback is called. But this code
will enable the clock when config_init() is called. I think you should
implement the enable and disable methods.
Andrew
