From d5f1e6a2bb61db8d4bd269edac8b52a853b48ce8 Mon Sep 17 00:00:00 2001 From: Dong Aisheng Date: Wed, 29 Jul 2020 16:00:15 +0800 Subject: [PATCH] clk: imx: imx8qxp-lpcg: add parsing clocks from device tree One LPCG controller supports up to 8 clock outputs while each of them is fixed to 4 bits. It supports only gating function with fixed bits. So we can use the clk-indices to fetch the corresponding clock idx from device tree. With this way, we can write a generic LPCG clock drivers. This patch add that support to parse clocks from device tree. Cc: Shawn Guo Cc: Sascha Hauer Cc: Michael Turquette Reviewed-by: Stephen Boyd Signed-off-by: Dong Aisheng Signed-off-by: Shawn Guo --- drivers/clk/imx/clk-imx8qxp-lpcg.c | 124 +++++++++++++++++++++++++++++++++++++ drivers/clk/imx/clk-lpcg-scu.c | 8 +++ drivers/clk/imx/clk-scu.h | 1 + 3 files changed, 133 insertions(+) diff --git a/drivers/clk/imx/clk-imx8qxp-lpcg.c b/drivers/clk/imx/clk-imx8qxp-lpcg.c index e947a70..84ac374 100644 --- a/drivers/clk/imx/clk-imx8qxp-lpcg.c +++ b/drivers/clk/imx/clk-imx8qxp-lpcg.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -157,6 +158,122 @@ static const struct imx8qxp_ss_lpcg imx8qxp_ss_lsio = { .num_max = IMX_LSIO_LPCG_CLK_END, }; +#define IMX_LPCG_MAX_CLKS 8 + +static struct clk_hw *imx_lpcg_of_clk_src_get(struct of_phandle_args *clkspec, + void *data) +{ + struct clk_hw_onecell_data *hw_data = data; + unsigned int idx = clkspec->args[0] / 4; + + if (idx >= hw_data->num) { + pr_err("%s: invalid index %u\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + return hw_data->hws[idx]; +} + +static int imx_lpcg_parse_clks_from_dt(struct platform_device *pdev, + struct device_node *np) +{ + const char *output_names[IMX_LPCG_MAX_CLKS]; + const char *parent_names[IMX_LPCG_MAX_CLKS]; + unsigned int bit_offset[IMX_LPCG_MAX_CLKS]; + struct clk_hw_onecell_data *clk_data; + struct clk_hw **clk_hws; + struct resource *res; + void __iomem *base; + int count; + int idx; + int ret; + int i; + + if (!of_device_is_compatible(np, "fsl,imx8qxp-lpcg")) + return -EINVAL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + count = of_property_count_u32_elems(np, "clock-indices"); + if (count < 0) { + dev_err(&pdev->dev, "failed to count clocks\n"); + return -EINVAL; + } + + /* + * A trick here is that we set the num of clks to the MAX instead + * of the count from clock-indices because one LPCG supports up to + * 8 clock outputs which each of them is fixed to 4 bits. Then we can + * easily get the clock by clk-indices (bit-offset) / 4. + * And the cost is very limited few pointers. + */ + + clk_data = devm_kzalloc(&pdev->dev, struct_size(clk_data, hws, + IMX_LPCG_MAX_CLKS), GFP_KERNEL); + if (!clk_data) + return -ENOMEM; + + clk_data->num = IMX_LPCG_MAX_CLKS; + clk_hws = clk_data->hws; + + ret = of_property_read_u32_array(np, "clock-indices", bit_offset, + count); + if (ret < 0) { + dev_err(&pdev->dev, "failed to read clock-indices\n"); + return -EINVAL; + } + + ret = of_clk_parent_fill(np, parent_names, count); + if (ret != count) { + dev_err(&pdev->dev, "failed to get clock parent names\n"); + return count; + } + + ret = of_property_read_string_array(np, "clock-output-names", + output_names, count); + if (ret != count) { + dev_err(&pdev->dev, "failed to read clock-output-names\n"); + return -EINVAL; + } + + for (i = 0; i < count; i++) { + idx = bit_offset[i] / 4; + if (idx > IMX_LPCG_MAX_CLKS) { + dev_warn(&pdev->dev, "invalid bit offset of clock %d\n", + i); + ret = -EINVAL; + goto unreg; + } + + clk_hws[idx] = imx_clk_lpcg_scu(output_names[i], + parent_names[i], 0, base, + bit_offset[i], false); + if (IS_ERR(clk_hws[idx])) { + dev_warn(&pdev->dev, "failed to register clock %d\n", + idx); + ret = PTR_ERR(clk_hws[idx]); + goto unreg; + } + } + + ret = devm_of_clk_add_hw_provider(&pdev->dev, imx_lpcg_of_clk_src_get, + clk_data); + if (!ret) + return 0; + +unreg: + while (--i >= 0) { + idx = bit_offset[i] / 4; + if (clk_hws[idx]) + imx_clk_lpcg_scu_unregister(clk_hws[idx]); + } + + return ret; +} + static int imx8qxp_lpcg_clk_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -167,8 +284,14 @@ static int imx8qxp_lpcg_clk_probe(struct platform_device *pdev) struct resource *res; struct clk_hw **clks; void __iomem *base; + int ret; int i; + /* try new binding to parse clocks from device tree first */ + ret = imx_lpcg_parse_clks_from_dt(pdev, np); + if (!ret) + return 0; + ss_lpcg = of_device_get_match_data(dev); if (!ss_lpcg) return -ENODEV; @@ -219,6 +342,7 @@ static const struct of_device_id imx8qxp_lpcg_match[] = { { .compatible = "fsl,imx8qxp-lpcg-adma", &imx8qxp_ss_adma, }, { .compatible = "fsl,imx8qxp-lpcg-conn", &imx8qxp_ss_conn, }, { .compatible = "fsl,imx8qxp-lpcg-lsio", &imx8qxp_ss_lsio, }, + { .compatible = "fsl,imx8qxp-lpcg", NULL }, { /* sentinel */ } }; diff --git a/drivers/clk/imx/clk-lpcg-scu.c b/drivers/clk/imx/clk-lpcg-scu.c index 1f0e44f..fab9c94 100644 --- a/drivers/clk/imx/clk-lpcg-scu.c +++ b/drivers/clk/imx/clk-lpcg-scu.c @@ -115,3 +115,11 @@ struct clk_hw *imx_clk_lpcg_scu(const char *name, const char *parent_name, return hw; } + +void imx_clk_lpcg_scu_unregister(struct clk_hw *hw) +{ + struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw); + + clk_hw_unregister(&clk->hw); + kfree(clk); +} diff --git a/drivers/clk/imx/clk-scu.h b/drivers/clk/imx/clk-scu.h index 22976d6..6a87952 100644 --- a/drivers/clk/imx/clk-scu.h +++ b/drivers/clk/imx/clk-scu.h @@ -47,4 +47,5 @@ static inline struct clk_hw *imx_clk_scu2(const char *name, const char * const * struct clk_hw *imx_clk_lpcg_scu(const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 bit_idx, bool hw_gate); +void imx_clk_lpcg_scu_unregister(struct clk_hw *hw); #endif -- 2.7.4