Quoting Wen He (2019-08-21 19:08:47)
> Add clock driver for QorIQ LS1028A Display output interfaces(LCD, DPHY),
> as implemented in TSMC CLN28HPM PLL, this PLL supports the programmable
> integer division and range of the display output pixel clock's 27-594MHz.
>
> Signed-off-by: Wen He <wen.he_1@xxxxxxx>
> ---
> change in v3:
> - remove the OF dependency
> - use clk_parent_data instead of parent_name
>
> drivers/clk/Kconfig | 10 ++
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-plldig.c | 283 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 294 insertions(+)
> create mode 100644 drivers/clk/clk-plldig.c
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 801fa1cd0321..ab05f342af04 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -223,6 +223,16 @@ config CLK_QORIQ
> This adds the clock driver support for Freescale QorIQ platforms
> using common clock framework.
>
> +config CLK_LS1028A_PLLDIG
> + bool "Clock driver for LS1028A Display output"
> + depends on ARCH_LAYERSCAPE || COMPILE_TEST
> + default ARCH_LAYERSCAPE
> + help
> + This driver support the Display output interfaces(LCD, DPHY) pixel clocks
> + of the QorIQ Layerscape LS1028A, as implemented TSMC CLN28HPM PLL. Not all
> + features of the PLL are currently supported by the driver. By default,
> + configured bypass mode with this PLL.
> +
> config COMMON_CLK_XGENE
> bool "Clock driver for APM XGene SoC"
> default ARCH_XGENE
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 0cad76021297..c8e22a764c4d 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_COMMON_CLK_OXNAS) += clk-oxnas.o
> obj-$(CONFIG_COMMON_CLK_PALMAS) += clk-palmas.o
> obj-$(CONFIG_COMMON_CLK_PWM) += clk-pwm.o
> obj-$(CONFIG_CLK_QORIQ) += clk-qoriq.o
> +obj-$(CONFIG_CLK_LS1028A_PLLDIG) += clk-plldig.o
> obj-$(CONFIG_COMMON_CLK_RK808) += clk-rk808.o
> obj-$(CONFIG_COMMON_CLK_HI655X) += clk-hi655x.o
> obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o
> diff --git a/drivers/clk/clk-plldig.c b/drivers/clk/clk-plldig.c
> new file mode 100644
> index 000000000000..c5ce80a46fd4
> --- /dev/null
> +++ b/drivers/clk/clk-plldig.c
> @@ -0,0 +1,283 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright 2019 NXP
Please leave this as C style /* */ comment for the NXP part, but comply
with the SPDX comment style of // on the first line.
> +
> +static long plldig_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *parent)
> +{
> + unsigned long parent_rate = *parent;
> + unsigned long round_rate;
> + u32 mult = 0, rfdphi1 = 0;
> + bool found = false;
> +
> + found = plldig_is_valid_range(rate, parent_rate, &mult,
> + &rfdphi1, &round_rate);
> + if (!found) {
> + pr_warn("%s: unable to round rate %lu, parent rate :%lu\n",
> + clk_hw_get_name(hw), rate, parent_rate);
> + return 0;
This can return an error instead? In fact, you may want to use
determine_rate clk op instead.
> + }
> +
> + return round_rate / rfdphi1;
> +}
> +
> +static int plldig_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_plldig *data = to_clk_plldig(hw);
> + bool valid = false;
> + unsigned long round_rate = 0;
> + u32 rfdphi1 = 0, val, mult = 0, cond = 0;
> + int ret = -ETIMEDOUT;
> +
> + valid = plldig_is_valid_range(rate, parent_rate, &mult,
> + &rfdphi1, &round_rate);
> + if (!valid) {
> + pr_warn("%s: unable to support rate %lu, parent_rate: %lu\n",
> + clk_hw_get_name(hw), rate, parent_rate);
Shouldn't determine_rate or round_rate make this impossible to hit in
practice? I mean that those ops should prevent the rate from being
rounded to such a frequency that it becomes invalid.
> + return -EINVAL;
> + }
> +
> + val = readl(data->regs + PLLDIG_REG_PLLDV);
> + val = mult;
> + rfdphi1 = PLLDIG_SET_RFDPHI1(rfdphi1);
> + val |= rfdphi1;
> +
> + writel(val, data->regs + PLLDIG_REG_PLLDV);
> +
> + /* delay 200us make sure that old lock state is cleared */
> + udelay(200);
> +
> + /* Wait until PLL is locked or timeout (maximum 1000 usecs) */
> + ret = readl_poll_timeout_atomic(data->regs + PLLDIG_REG_PLLSR, cond,
> + cond & PLLDIG_LOCK_MASK, 0,
> + USEC_PER_MSEC);
> +
> + return ret;
> +}
> +
> +static const struct clk_ops plldig_clk_ops = {
> + .enable = plldig_enable,
> + .disable = plldig_disable,
> + .is_enabled = plldig_is_enabled,
> + .recalc_rate = plldig_recalc_rate,
> + .round_rate = plldig_round_rate,
> + .set_rate = plldig_set_rate,
> +};
[...]
> +
> + ret = devm_clk_hw_register(dev, &data->hw);
> + if (ret) {
> + dev_err(dev, "failed to register %s clock\n", init.name);
> + return ret;
> + }
> +
> + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, &data->hw);
> + if (ret)
> + dev_err(dev, "failed adding the clock provider\n");
> +
> + return ret;
> +}
> +
> +static int plldig_clk_remove(struct platform_device *pdev)
> +{
> + of_clk_del_provider(pdev->dev.of_node);
This isn't required. devm already does it.
> + return 0;
> +}
> +
> +static const struct of_device_id plldig_clk_id[] = {
> + { .compatible = "fsl,ls1028a-plldig", .data = NULL},
You can leave out the data assignment.
