On Fri, 2020-08-14 at 15:09 +0300, Abel Vesa wrote:
> On i.MX8MP, there is a new type of IP which is called BLK_CTRL in
> RM and usually is comprised of some GPRs that are considered too
> generic to be part of any dedicated IP from that specific subsystem.
>
> In general, some of the GPRs have some clock bits, some have reset bits,
> so in order to be able to use the imx clock API, this needs to be
> in a clock driver. From there it can use the reset controller API and
> leave the rest to the syscon.
>
> This driver is intended to work with the following BLK_CTRL IPs found in
> i.MX8MP (but it might be reused by the future i.MX platforms that
> have this kind of IP in their design):
> - Audio
> - Media
> - HDMI
>
> Signed-off-by: Abel Vesa <abel.vesa@xxxxxxx>
> ---
> drivers/clk/imx/Makefile | 2 +-
> drivers/clk/imx/clk-blk-ctrl.c | 327 +++++++++++++++++++++++++++++++++++++++++
> drivers/clk/imx/clk-blk-ctrl.h | 81 ++++++++++
> 3 files changed, 409 insertions(+), 1 deletion(-)
> create mode 100644 drivers/clk/imx/clk-blk-ctrl.c
> create mode 100644 drivers/clk/imx/clk-blk-ctrl.h
>
> diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
> index 928f874c..7afe1df 100644
> --- a/drivers/clk/imx/Makefile
> +++ b/drivers/clk/imx/Makefile
> @@ -27,7 +27,7 @@ obj-$(CONFIG_MXC_CLK_SCU) += \
>
> obj-$(CONFIG_CLK_IMX8MM) += clk-imx8mm.o
> obj-$(CONFIG_CLK_IMX8MN) += clk-imx8mn.o
> -obj-$(CONFIG_CLK_IMX8MP) += clk-imx8mp.o
> +obj-$(CONFIG_CLK_IMX8MP) += clk-imx8mp.o clk-blk-ctrl.o
> obj-$(CONFIG_CLK_IMX8MQ) += clk-imx8mq.o
> obj-$(CONFIG_CLK_IMX8QXP) += clk-imx8qxp.o clk-imx8qxp-lpcg.o
>
> diff --git a/drivers/clk/imx/clk-blk-ctrl.c b/drivers/clk/imx/clk-blk-ctrl.c
> new file mode 100644
> index 00000000..1672646
> --- /dev/null
> +++ b/drivers/clk/imx/clk-blk-ctrl.c
> @@ -0,0 +1,327 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2020 NXP.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/reset-controller.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +
> +#include "clk.h"
> +#include "clk-blk-ctrl.h"
> +
> +struct reset_hw {
> + u32 offset;
> + u32 shift;
> + u32 mask;
> + bool asserted;
> +};
> +
> +struct pm_safekeep_info {
> + uint32_t *regs_values;
> + uint32_t *regs_offsets;
> + uint32_t regs_num;
> +};
> +
> +struct imx_blk_ctrl_drvdata {
> + void __iomem *base;
> + struct reset_controller_dev rcdev;
> + struct reset_hw *rst_hws;
> + struct pm_safekeep_info pm_info;
> +
> + spinlock_t lock;
> +};
> +
> +static int imx_blk_ctrl_reset_set(struct reset_controller_dev *rcdev,
> + unsigned long id, bool assert)
> +{
> + struct imx_blk_ctrl_drvdata *drvdata = container_of(rcdev,
> + struct imx_blk_ctrl_drvdata, rcdev);
> + unsigned int offset = drvdata->rst_hws[id].offset;
> + unsigned int shift = drvdata->rst_hws[id].shift;
> + unsigned int mask = drvdata->rst_hws[id].mask;
> + void __iomem *reg_addr = drvdata->base + offset;
> + unsigned long flags;
> + unsigned int asserted_before = 0, asserted_after = 0;
> + u32 reg;
> + int i;
> +
> + spin_lock_irqsave(&drvdata->lock, flags);
> +
> + for (i = 0; i < drvdata->rcdev.nr_resets; i++)
> + if (drvdata->rst_hws[i].asserted)
> + asserted_before++;
> +
> + if (asserted_before == 0 && assert)
> + pm_runtime_get(rcdev->dev);
Shouldn't that be pm_runtime_get_sync() ?
I would do that unconditionally before locking drvdata->lock and then
drop unnecessary refcounts afterwards.
> +
> + if (assert) {
> + reg = readl(reg_addr);
> + writel(reg & ~(mask << shift), reg_addr);
> + drvdata->rst_hws[id].asserted = true;
> + } else {
> + reg = readl(reg_addr);
> + writel(reg | (mask << shift), reg_addr);
> + drvdata->rst_hws[id].asserted = false;
> + }
> +
> + for (i = 0; i < drvdata->rcdev.nr_resets; i++)
> + if (drvdata->rst_hws[i].asserted)
> + asserted_after++;
> +
> + if (asserted_before == 1 && asserted_after == 0)
> + pm_runtime_put(rcdev->dev);
> +
> + spin_unlock_irqrestore(&drvdata->lock, flags);
> +
> + return 0;
> +}
regards
Philipp
