Re: [PATCH V4 4/5] clk: imx: support fracn gppll
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: 2022-02-24 09:59:04
Also in:
linux-clk, linux-devicetree, lkml
On Thu, Feb 24, 2022 at 04:22:50PM +0800, Peng Fan (OSS) wrote:
quoted hunk ↗ jump to hunk
From: Peng Fan <peng.fan@nxp.com> This PLL module is a Fractional-N synthesizer, supporting 30-bit numerator and denominator. Numerator is a signed number. It has feature to adjust fractional portion of feedback divider dynamically. This fracn gppll is used in i.MX93. Reviewed-by: Abel Vesa <redacted> Signed-off-by: Peng Fan <peng.fan@nxp.com> --- drivers/clk/imx/Makefile | 1 + drivers/clk/imx/clk-fracn-gppll.c | 326 ++++++++++++++++++++++++++++++ drivers/clk/imx/clk.h | 21 ++ 3 files changed, 348 insertions(+) create mode 100644 drivers/clk/imx/clk-fracn-gppll.cdiff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile index 36c04922d789..60c8a4bb7574 100644 --- a/drivers/clk/imx/Makefile +++ b/drivers/clk/imx/Makefile@@ -5,6 +5,7 @@ mxc-clk-objs += clk-busy.o mxc-clk-objs += clk-composite-7ulp.o mxc-clk-objs += clk-composite-8m.o mxc-clk-objs += clk-composite-93.o +mxc-clk-objs += clk-fracn-gppll.o mxc-clk-objs += clk-cpu.o mxc-clk-objs += clk-divider-gate.o mxc-clk-objs += clk-fixup-div.odiff --git a/drivers/clk/imx/clk-fracn-gppll.c b/drivers/clk/imx/clk-fracn-gppll.c new file mode 100644 index 000000000000..b6add3a2e472 --- /dev/null +++ b/drivers/clk/imx/clk-fracn-gppll.c@@ -0,0 +1,326 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2021 NXP + */ + +#include <asm/div64.h> +#include <linux/bitfield.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/slab.h> +#include <linux/jiffies.h> + +#include "clk.h" + +#define PLL_CTRL 0x0 +#define CLKMUX_BYPASS BIT(2) +#define CLKMUX_EN BIT(1) +#define POWERUP_MASK BIT(0) + +#define PLL_ANA_PRG 0x10 +#define PLL_SPREAD_SPECTRUM 0x30 + +#define PLL_NUMERATOR 0x40 +#define PLL_MFN_MASK GENMASK(31, 2) +#define PLL_MFN_SHIFT 2 + +#define PLL_DENOMINATOR 0x50 +#define PLL_MFD_MASK GENMASK(29, 0) + +#define PLL_DIV 0x60 +#define PLL_MFI_MASK GENMASK(24, 16)
Is the MFI field really 9 bits wide? Could be, I don't have the reference manual. It just looks like it could be a one-off.
+#define PLL_MFI_SHIFT 16 +#define PLL_RDIV_MASK GENMASK(15, 13) +#define PLL_RDIV_SHIFT 13 +#define PLL_ODIV_MASK GENMASK(7, 0)
The *_SHIFT defines can be removed.
+static int clk_fracn_gppll_set_rate(struct clk_hw *hw, unsigned long drate,
+ unsigned long prate)
+{
+ struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
+ const struct imx_fracn_gppll_rate_table *rate;
+ u32 tmp, pll_div, ana_mfn;
+ int ret;
+
+ rate = imx_get_pll_settings(pll, drate);
+
+ /* Disable output */
+ tmp = readl_relaxed(pll->base + PLL_CTRL);
+ tmp &= ~CLKMUX_EN;
+ writel_relaxed(tmp, pll->base + PLL_CTRL);
+
+ /* Power Down */
+ tmp &= ~POWERUP_MASK;
+ writel_relaxed(tmp, pll->base + PLL_CTRL);
+
+ /* Disable BYPASS */
+ tmp &= ~CLKMUX_BYPASS;
+ writel_relaxed(tmp, pll->base + PLL_CTRL);
+
+ pll_div = FIELD_PREP(PLL_RDIV_MASK, rate->rdiv) | rate->odiv |
+ FIELD_PREP(PLL_MFI_MASK, rate->mfi);
+ writel_relaxed(pll_div, pll->base + PLL_DIV);
+ writel_relaxed(rate->mfd, pll->base + PLL_DENOMINATOR);
+ writel_relaxed(rate->mfn << PLL_MFN_SHIFT, pll->base + PLL_NUMERATOR);FIELD_PREP
+ + /* Wait for 5us according to fracn mode pll doc */ + udelay(5); + + /* Enable Powerup */ + tmp |= POWERUP_MASK; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + /* Wait Lock */ + ret = clk_fracn_gppll_wait_lock(pll); + if (ret) + return ret; + + /* Enable output */ + tmp |= CLKMUX_EN; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + ana_mfn = (readl_relaxed(pll->base + PLL_STATUS) & PLL_MFN_MASK) >> PLL_MFN_SHIFT;
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