From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Martin Blumenstingl To: linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org, mturquette@baylibre.com Cc: linux-arm-kernel@lists.infradead.org, narmstrong@baylibre.com, jbrunet@baylibre.com, khilman@baylibre.com, carlo@caione.org, sboyd@codeaurora.org, Martin Blumenstingl Subject: [RFC PATCH] clk: meson: gxbb: remove the "cpu_clk" Date: Sun, 26 Mar 2017 13:06:02 +0200 Message-Id: <20170326110602.23379-1-martin.blumenstingl@googlemail.com> List-ID: It seems that the "cpu_clk" was carried over from the meson8b clock controller driver. On Meson GX (GXBB/GXL/GXM) the registers which are used by the cpu_clk have a different purpose (in other words: they don't control the CPU clock anymore). HHI_SYS_CPU_CLK_CNTL1 bits 31:24 are reserved according to the public S905 datasheet, while bit 23 is the "A53_trace_clk_DIS" gate (which according to the datasheet should only be used in case a silicon bug is discovered) and bits 22:20 are a divider (A53_trace_clk). The meson clk-cpu code however expects that bits 28:20 are reserved for a divider (according to the public S805 datasheet this "SCALE_DIV: This value represents an N+1 divider of the input clock."). The CPU clock on Meson GX SoCs is provided by the SCPI DVFS clock driver instead. Two examples from a Meson GXL S905X SoC: - vcpu (SCPI DVFS clock 0) rate: 1000000000 / cpu_clk rate: 708000000 - vcpu (SCPI DVFS clock 0) rate: 1512000000 / cpu_clk rate: 708000000 Unfortunately the CLKID_CPUCLK was already exported (but is currently not used) to DT. This is an RFC because I would like to hear other people's opinion on how to clean up the CLKID_CPUCLK (as it leaves a "hole" in gxbb_hw_onecell_data and changes the DT API (by removing a currently unused #define). Signed-off-by: Martin Blumenstingl --- drivers/clk/meson/gxbb.c | 44 +++-------------------------------- drivers/clk/meson/gxbb.h | 2 +- include/dt-bindings/clock/gxbb-clkc.h | 1 - 3 files changed, 4 insertions(+), 43 deletions(-) diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c index 1c1ec137a3cc..06586fe16ce3 100644 --- a/drivers/clk/meson/gxbb.c +++ b/drivers/clk/meson/gxbb.c @@ -496,21 +496,10 @@ static struct meson_clk_mpll gxbb_mpll2 = { }; /* - * FIXME cpu clocks and the legacy composite clocks (e.g. clk81) are both PLL - * post-dividers and should be modeled with their respective PLLs via the - * forthcoming coordinated clock rates feature + * FIXME The legacy composite clocks (e.g. clk81) are both PLL post-dividers + * and should be modeled with their respective PLLs via the forthcoming + * coordinated clock rates feature */ -static struct meson_clk_cpu gxbb_cpu_clk = { - .reg_off = HHI_SYS_CPU_CLK_CNTL1, - .div_table = cpu_div_table, - .clk_nb.notifier_call = meson_clk_cpu_notifier_cb, - .hw.init = &(struct clk_init_data){ - .name = "cpu_clk", - .ops = &meson_clk_cpu_ops, - .parent_names = (const char *[]){ "sys_pll" }, - .num_parents = 1, - }, -}; static u32 mux_table_clk81[] = { 6, 5, 7 }; @@ -698,7 +687,6 @@ static MESON_GATE(gxbb_ao_i2c, HHI_GCLK_AO, 4); static struct clk_hw_onecell_data gxbb_hw_onecell_data = { .hws = { [CLKID_SYS_PLL] = &gxbb_sys_pll.hw, - [CLKID_CPUCLK] = &gxbb_cpu_clk.hw, [CLKID_HDMI_PLL] = &gxbb_hdmi_pll.hw, [CLKID_FIXED_PLL] = &gxbb_fixed_pll.hw, [CLKID_FCLK_DIV2] = &gxbb_fclk_div2.hw, @@ -925,9 +913,6 @@ static int gxbb_clkc_probe(struct platform_device *pdev) for (i = 0; i < ARRAY_SIZE(gxbb_clk_mplls); i++) gxbb_clk_mplls[i]->base = clk_base; - /* Populate the base address for CPU clk */ - gxbb_cpu_clk.base = clk_base; - /* Populate the base address for the MPEG clks */ gxbb_mpeg_clk_sel.reg = clk_base + (u64)gxbb_mpeg_clk_sel.reg; gxbb_mpeg_clk_div.reg = clk_base + (u64)gxbb_mpeg_clk_div.reg; @@ -950,29 +935,6 @@ static int gxbb_clkc_probe(struct platform_device *pdev) goto iounmap; } - /* - * Register CPU clk notifier - * - * FIXME this is wrong for a lot of reasons. First, the muxes should be - * struct clk_hw objects. Second, we shouldn't program the muxes in - * notifier handlers. The tricky programming sequence will be handled - * by the forthcoming coordinated clock rates mechanism once that - * feature is released. - * - * Furthermore, looking up the parent this way is terrible. At some - * point we will stop allocating a default struct clk when registering - * a new clk_hw, and this hack will no longer work. Releasing the ccr - * feature before that time solves the problem :-) - */ - parent_hw = clk_hw_get_parent(&gxbb_cpu_clk.hw); - parent_clk = parent_hw->clk; - ret = clk_notifier_register(parent_clk, &gxbb_cpu_clk.clk_nb); - if (ret) { - pr_err("%s: failed to register clock notifier for cpu_clk\n", - __func__); - goto iounmap; - } - return of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get, &gxbb_hw_onecell_data); diff --git a/drivers/clk/meson/gxbb.h b/drivers/clk/meson/gxbb.h index cbd62e46bb5b..ca1285acb92d 100644 --- a/drivers/clk/meson/gxbb.h +++ b/drivers/clk/meson/gxbb.h @@ -169,7 +169,7 @@ * to be exposed to client nodes in DT: include/dt-bindings/clock/gxbb-clkc.h */ #define CLKID_SYS_PLL 0 -/* CLKID_CPUCLK */ +/* CLKID_CPUCLK - not used in the driver anymore */ /* CLKID_HDMI_PLL */ #define CLKID_FIXED_PLL 3 /* CLKID_FCLK_DIV2 */ diff --git a/include/dt-bindings/clock/gxbb-clkc.h b/include/dt-bindings/clock/gxbb-clkc.h index 63f4c2c44a1f..07311dfdba83 100644 --- a/include/dt-bindings/clock/gxbb-clkc.h +++ b/include/dt-bindings/clock/gxbb-clkc.h @@ -5,7 +5,6 @@ #ifndef __GXBB_CLKC_H #define __GXBB_CLKC_H -#define CLKID_CPUCLK 1 #define CLKID_HDMI_PLL 2 #define CLKID_FCLK_DIV2 4 #define CLKID_FCLK_DIV3 5 -- 2.12.1