[RESEND PATCH v3 3/6] soc: xilinx: vcu: implement clock provider for output clocks
Rajan Vaja
RAJANV at xilinx.com
Tue Jul 21 02:59:47 EDT 2020
Hi Michael,
Thanks for the patch.
-----Original Message-----
> From: Michael Tretter <m.tretter at pengutronix.de>
> Sent: 19 June 2020 01:29 PM
> To: linux-arm-kernel at lists.infradead.org
> Cc: Rohit Visavalia <RVISAVAL at xilinx.com>; Michal Simek <michals at xilinx.com>;
> Dhaval Rajeshbhai Shah <dshah at xilinx.com>; Greg Kroah-Hartman
> <gregkh at linuxfoundation.org>; kernel at pengutronix.de; Michael Tretter
> <m.tretter at pengutronix.de>
> Subject: [RESEND PATCH v3 3/6] soc: xilinx: vcu: implement clock provider for
> output clocks
>
> CAUTION: This message has originated from an External Source. Please use proper
> judgment and caution when opening attachments, clicking links, or responding to
> this email.
>
>
> The VCU System-Level Control uses an internal PLL to drive the core and
> MCU clock for the allegro encoder and decoder based on an external PL
> clock.
>
> In order be able to ensure that the clocks are enabled and to get their
> rate from other drivers, the module must implement a clock provider and
> register the clocks at the common clock framework. Other drivers are
> then able to access the clock via devicetree bindings.
>
> Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
> ---
> drivers/soc/xilinx/Kconfig | 2 +-
> drivers/soc/xilinx/xlnx_vcu.c | 64 +++++++++++++++++++++++++++++++++--
> 2 files changed, 63 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/soc/xilinx/Kconfig b/drivers/soc/xilinx/Kconfig
> index 646512d7276f..2a4e80a36f78 100644
> --- a/drivers/soc/xilinx/Kconfig
> +++ b/drivers/soc/xilinx/Kconfig
> @@ -3,7 +3,7 @@ menu "Xilinx SoC drivers"
>
> config XILINX_VCU
> tristate "Xilinx VCU logicoreIP Init"
> - depends on HAS_IOMEM
> + depends on HAS_IOMEM && COMMON_CLK
> help
> Provides the driver to enable and disable the isolation between the
> processing system and programmable logic part by using the logicoreIP
> diff --git a/drivers/soc/xilinx/xlnx_vcu.c b/drivers/soc/xilinx/xlnx_vcu.c
> index dcd8e7824b06..03bf252737aa 100644
> --- a/drivers/soc/xilinx/xlnx_vcu.c
> +++ b/drivers/soc/xilinx/xlnx_vcu.c
> @@ -7,6 +7,7 @@
> * Contacts Dhaval Shah <dshah at xilinx.com>
> */
> #include <linux/clk.h>
> +#include <linux/clk-provider.h>
> #include <linux/device.h>
> #include <linux/errno.h>
> #include <linux/io.h>
> @@ -14,6 +15,8 @@
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
>
> +#include <dt-bindings/clock/xlnx-vcu.h>
> +
> /* Address map for different registers implemented in the VCU LogiCORE IP. */
> #define VCU_ECODER_ENABLE 0x00
> #define VCU_DECODER_ENABLE 0x04
> @@ -108,7 +111,9 @@ struct xvcu_device {
> struct clk *aclk;
> void __iomem *logicore_reg_ba;
> void __iomem *vcu_slcr_ba;
> + struct clk_onecell_data clk_data;
> u32 coreclk;
> + u32 mcuclk;
> };
>
> /**
> @@ -375,10 +380,10 @@ static int xvcu_set_vcu_pll_info(struct xvcu_device
> *xvcu)
> }
>
> xvcu->coreclk = pll_clk / divisor_core;
> - mcuclk = pll_clk / divisor_mcu;
> + xvcu->mcuclk = pll_clk / divisor_mcu;
> dev_dbg(xvcu->dev, "Actual Ref clock freq is %uHz\n", refclk);
> dev_dbg(xvcu->dev, "Actual Core clock freq is %uHz\n", xvcu->coreclk);
> - dev_dbg(xvcu->dev, "Actual Mcu clock freq is %uHz\n", mcuclk);
> + dev_dbg(xvcu->dev, "Actual Mcu clock freq is %uHz\n", xvcu->mcuclk);
>
> vcu_pll_ctrl &= ~(VCU_PLL_CTRL_FBDIV_MASK <<
> VCU_PLL_CTRL_FBDIV_SHIFT);
> vcu_pll_ctrl |= (found->fbdiv & VCU_PLL_CTRL_FBDIV_MASK) <<
> @@ -485,6 +490,51 @@ static int xvcu_set_pll(struct xvcu_device *xvcu)
> return -ETIMEDOUT;
> }
>
> +static int xvcu_register_clock_provider(struct xvcu_device *xvcu)
> +{
> + struct device *dev = xvcu->dev;
> + const char *parent_name = __clk_get_name(xvcu->pll_ref);
> + struct clk_onecell_data *data = &xvcu->clk_data;
> + struct clk **clks;
> + size_t num_clks = CLK_XVCU_MAX;
> +
> + clks = devm_kcalloc(dev, num_clks, sizeof(*clks), GFP_KERNEL);
> + if (!clks)
> + return -ENOMEM;
> +
> + data->clk_num = num_clks;
> + data->clks = clks;
> +
> + clks[CLK_XVCU_ENC_CORE] =
> + clk_register_fixed_rate(dev, "venc_core_clk",
> + parent_name, 0, xvcu->coreclk);
> + clks[CLK_XVCU_ENC_MCU] =
> + clk_register_fixed_rate(dev, "venc_mcu_clk",
> + parent_name, 0, xvcu->mcuclk);
> + clks[CLK_XVCU_DEC_CORE] =
> + clk_register_fixed_rate(dev, "vdec_core_clk",
> + parent_name, 0, xvcu->coreclk);
> + clks[CLK_XVCU_DEC_MCU] =
> + clk_register_fixed_rate(dev, "vdec_mcu_clk",
> + parent_name, 0, xvcu->mcuclk);
> +
[Rajan] These clocks are not fixed rate clock. These clocks are mux-->div-->gate clock.
Can we separate out clock provider as a different kernel modules instead of having it in VCU driver it self?
We have already implemented clock provider https://github.com/Xilinx/linux-xlnx/blob/master/drivers/soc/xilinx/xlnx_vcu_clk.c and removed manual rate calculation
as separate kernel module. You can refer it, and see if it works for you.
Thanks,
Rajan
> + return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get, data);
> +}
> +
> +static void xvcu_unregister_clock_provider(struct xvcu_device *xvcu)
> +{
> + struct device *dev = xvcu->dev;
> + struct clk_onecell_data *data = &xvcu->clk_data;
> + struct clk **clks = data->clks;
> +
> + of_clk_del_provider(dev->of_node);
> +
> + clk_unregister_fixed_rate(clks[CLK_XVCU_DEC_MCU]);
> + clk_unregister_fixed_rate(clks[CLK_XVCU_DEC_CORE]);
> + clk_unregister_fixed_rate(clks[CLK_XVCU_ENC_MCU]);
> + clk_unregister_fixed_rate(clks[CLK_XVCU_ENC_CORE]);
> +}
> +
> /**
> * xvcu_probe - Probe existence of the logicoreIP
> * and initialize PLL
> @@ -569,10 +619,18 @@ static int xvcu_probe(struct platform_device *pdev)
> goto error_pll_ref;
> }
>
> + ret = xvcu_register_clock_provider(xvcu);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to register clock provider\n");
> + goto error_clk_provider;
> + }
> +
> dev_set_drvdata(&pdev->dev, xvcu);
>
> return 0;
>
> +error_clk_provider:
> + xvcu_unregister_clock_provider(xvcu);
> error_pll_ref:
> clk_disable_unprepare(xvcu->pll_ref);
> error_aclk:
> @@ -596,6 +654,8 @@ static int xvcu_remove(struct platform_device *pdev)
> if (!xvcu)
> return -ENODEV;
>
> + xvcu_unregister_clock_provider(xvcu);
> +
> /* Add the the Gasket isolation and put the VCU in reset. */
> xvcu_write(xvcu->logicore_reg_ba, VCU_GASKET_INIT, 0);
>
> --
> 2.20.1
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