diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/sunxi-ng/ccu-sun6i-rtc.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c new file mode 100644 index 000000000..d65398497 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Copyright (c) 2021 Samuel Holland <samuel@sholland.org> +// + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_device.h> + +#include <linux/clk/sunxi-ng.h> + +#include "ccu_common.h" + +#include "ccu_div.h" +#include "ccu_gate.h" +#include "ccu_mux.h" + +#include "ccu-sun6i-rtc.h" + +#define IOSC_ACCURACY 300000000 /* 30% */ +#define IOSC_RATE 16000000 + +#define LOSC_RATE 32768 +#define LOSC_RATE_SHIFT 15 + +#define LOSC_CTRL_REG 0x0 +#define LOSC_CTRL_KEY 0x16aa0000 + +#define IOSC_32K_CLK_DIV_REG 0x8 +#define IOSC_32K_CLK_DIV GENMASK(4, 0) +#define IOSC_32K_PRE_DIV 32 + +#define IOSC_CLK_CALI_REG 0xc +#define IOSC_CLK_CALI_DIV_ONES 22 +#define IOSC_CLK_CALI_EN BIT(1) +#define IOSC_CLK_CALI_SRC_SEL BIT(0) + +#define LOSC_OUT_GATING_REG 0x60 + +#define DCXO_CTRL_REG 0x160 +#define DCXO_CTRL_CLK16M_RC_EN BIT(0) + +struct sun6i_rtc_match_data { + bool have_ext_osc32k : 1; + bool have_iosc_calibration : 1; + bool rtc_32k_single_parent : 1; + const struct clk_parent_data *osc32k_fanout_parents; + u8 osc32k_fanout_nparents; +}; + +static bool have_iosc_calibration; + +static int ccu_iosc_enable(struct clk_hw *hw) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + + return ccu_gate_helper_enable(cm, DCXO_CTRL_CLK16M_RC_EN); +} + +static void ccu_iosc_disable(struct clk_hw *hw) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + + return ccu_gate_helper_disable(cm, DCXO_CTRL_CLK16M_RC_EN); +} + +static int ccu_iosc_is_enabled(struct clk_hw *hw) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + + return ccu_gate_helper_is_enabled(cm, DCXO_CTRL_CLK16M_RC_EN); +} + +static unsigned long ccu_iosc_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + + if (have_iosc_calibration) { + u32 reg = readl(cm->base + IOSC_CLK_CALI_REG); + + /* + * Recover the IOSC frequency by shifting the ones place of + * (fixed-point divider * 32768) into bit zero. + */ + if (reg & IOSC_CLK_CALI_EN) + return reg >> (IOSC_CLK_CALI_DIV_ONES - LOSC_RATE_SHIFT); + } + + return IOSC_RATE; +} + +static unsigned long ccu_iosc_recalc_accuracy(struct clk_hw *hw, + unsigned long parent_accuracy) +{ + return IOSC_ACCURACY; +} + +static const struct clk_ops ccu_iosc_ops = { + .enable = ccu_iosc_enable, + .disable = ccu_iosc_disable, + .is_enabled = ccu_iosc_is_enabled, + .recalc_rate = ccu_iosc_recalc_rate, + .recalc_accuracy = ccu_iosc_recalc_accuracy, +}; + +static struct ccu_common iosc_clk = { + .reg = DCXO_CTRL_REG, + .hw.init = CLK_HW_INIT_NO_PARENT("iosc", &ccu_iosc_ops, + CLK_GET_RATE_NOCACHE), +}; + +static int ccu_iosc_32k_prepare(struct clk_hw *hw) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + u32 val; + + if (!have_iosc_calibration) + return 0; + + val = readl(cm->base + IOSC_CLK_CALI_REG); + writel(val | IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL, + cm->base + IOSC_CLK_CALI_REG); + + return 0; +} + +static void ccu_iosc_32k_unprepare(struct clk_hw *hw) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + u32 val; + + if (!have_iosc_calibration) + return; + + val = readl(cm->base + IOSC_CLK_CALI_REG); + writel(val & ~(IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL), + cm->base + IOSC_CLK_CALI_REG); +} + +static unsigned long ccu_iosc_32k_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + u32 val; + + if (have_iosc_calibration) { + val = readl(cm->base + IOSC_CLK_CALI_REG); + + /* Assume the calibrated 32k clock is accurate. */ + if (val & IOSC_CLK_CALI_SRC_SEL) + return LOSC_RATE; + } + + val = readl(cm->base + IOSC_32K_CLK_DIV_REG) & IOSC_32K_CLK_DIV; + + return parent_rate / IOSC_32K_PRE_DIV / (val + 1); +} + +static unsigned long ccu_iosc_32k_recalc_accuracy(struct clk_hw *hw, + unsigned long parent_accuracy) +{ + struct ccu_common *cm = hw_to_ccu_common(hw); + u32 val; + + if (have_iosc_calibration) { + val = readl(cm->base + IOSC_CLK_CALI_REG); + + /* Assume the calibrated 32k clock is accurate. */ + if (val & IOSC_CLK_CALI_SRC_SEL) + return 0; + } + + return parent_accuracy; +} + +static const struct clk_ops ccu_iosc_32k_ops = { + .prepare = ccu_iosc_32k_prepare, + .unprepare = ccu_iosc_32k_unprepare, + .recalc_rate = ccu_iosc_32k_recalc_rate, + .recalc_accuracy = ccu_iosc_32k_recalc_accuracy, +}; + +static struct ccu_common iosc_32k_clk = { + .hw.init = CLK_HW_INIT_HW("iosc-32k", &iosc_clk.hw, + &ccu_iosc_32k_ops, + CLK_GET_RATE_NOCACHE), +}; + +static const struct clk_hw *ext_osc32k[] = { NULL }; /* updated during probe */ + +static SUNXI_CCU_GATE_HWS(ext_osc32k_gate_clk, "ext-osc32k-gate", + ext_osc32k, 0x0, BIT(4), 0); + +static const struct clk_hw *osc32k_parents[] = { + &iosc_32k_clk.hw, + &ext_osc32k_gate_clk.common.hw +}; + +static struct clk_init_data osc32k_init_data = { + .name = "osc32k", + .ops = &ccu_mux_ops, + .parent_hws = osc32k_parents, + .num_parents = ARRAY_SIZE(osc32k_parents), /* updated during probe */ +}; + +static struct ccu_mux osc32k_clk = { + .mux = _SUNXI_CCU_MUX(0, 1), + .common = { + .reg = LOSC_CTRL_REG, + .features = CCU_FEATURE_KEY_FIELD, + .hw.init = &osc32k_init_data, + }, +}; + +/* This falls back to the global name for fwnodes without a named reference. */ +static const struct clk_parent_data osc24M[] = { + { .fw_name = "hosc", .name = "osc24M" } +}; + +static struct ccu_gate osc24M_32k_clk = { + .enable = BIT(16), + .common = { + .reg = LOSC_OUT_GATING_REG, + .prediv = 750, + .features = CCU_FEATURE_ALL_PREDIV, + .hw.init = CLK_HW_INIT_PARENTS_DATA("osc24M-32k", osc24M, + &ccu_gate_ops, 0), + }, +}; + +static const struct clk_hw *rtc_32k_parents[] = { + &osc32k_clk.common.hw, + &osc24M_32k_clk.common.hw +}; + +static struct clk_init_data rtc_32k_init_data = { + .name = "rtc-32k", + .ops = &ccu_mux_ops, + .parent_hws = rtc_32k_parents, + .num_parents = ARRAY_SIZE(rtc_32k_parents), /* updated during probe */ + .flags = CLK_IS_CRITICAL, +}; + +static struct ccu_mux rtc_32k_clk = { + .mux = _SUNXI_CCU_MUX(1, 1), + .common = { + .reg = LOSC_CTRL_REG, + .features = CCU_FEATURE_KEY_FIELD, + .hw.init = &rtc_32k_init_data, + }, +}; + +static struct clk_init_data osc32k_fanout_init_data = { + .name = "osc32k-fanout", + .ops = &ccu_mux_ops, + /* parents are set during probe */ +}; + +static struct ccu_mux osc32k_fanout_clk = { + .enable = BIT(0), + .mux = _SUNXI_CCU_MUX(1, 2), + .common = { + .reg = LOSC_OUT_GATING_REG, + .hw.init = &osc32k_fanout_init_data, + }, +}; + +static struct ccu_common *sun6i_rtc_ccu_clks[] = { + &iosc_clk, + &iosc_32k_clk, + &ext_osc32k_gate_clk.common, + &osc32k_clk.common, + &osc24M_32k_clk.common, + &rtc_32k_clk.common, + &osc32k_fanout_clk.common, +}; + +static struct clk_hw_onecell_data sun6i_rtc_ccu_hw_clks = { + .num = CLK_NUMBER, + .hws = { + [CLK_OSC32K] = &osc32k_clk.common.hw, + [CLK_OSC32K_FANOUT] = &osc32k_fanout_clk.common.hw, + [CLK_IOSC] = &iosc_clk.hw, + [CLK_IOSC_32K] = &iosc_32k_clk.hw, + [CLK_EXT_OSC32K_GATE] = &ext_osc32k_gate_clk.common.hw, + [CLK_OSC24M_32K] = &osc24M_32k_clk.common.hw, + [CLK_RTC_32K] = &rtc_32k_clk.common.hw, + }, +}; + +static const struct sunxi_ccu_desc sun6i_rtc_ccu_desc = { + .ccu_clks = sun6i_rtc_ccu_clks, + .num_ccu_clks = ARRAY_SIZE(sun6i_rtc_ccu_clks), + + .hw_clks = &sun6i_rtc_ccu_hw_clks, +}; + +static const struct clk_parent_data sun50i_h616_osc32k_fanout_parents[] = { + { .hw = &osc32k_clk.common.hw }, + { .fw_name = "pll-32k" }, + { .hw = &osc24M_32k_clk.common.hw } +}; + +static const struct clk_parent_data sun50i_r329_osc32k_fanout_parents[] = { + { .hw = &osc32k_clk.common.hw }, + { .hw = &ext_osc32k_gate_clk.common.hw }, + { .hw = &osc24M_32k_clk.common.hw } +}; + +static const struct sun6i_rtc_match_data sun50i_h616_rtc_ccu_data = { + .have_iosc_calibration = true, + .rtc_32k_single_parent = true, + .osc32k_fanout_parents = sun50i_h616_osc32k_fanout_parents, + .osc32k_fanout_nparents = ARRAY_SIZE(sun50i_h616_osc32k_fanout_parents), +}; + +static const struct sun6i_rtc_match_data sun50i_r329_rtc_ccu_data = { + .have_ext_osc32k = true, + .osc32k_fanout_parents = sun50i_r329_osc32k_fanout_parents, + .osc32k_fanout_nparents = ARRAY_SIZE(sun50i_r329_osc32k_fanout_parents), +}; + +static const struct of_device_id sun6i_rtc_ccu_match[] = { + { + .compatible = "allwinner,sun50i-h616-rtc", + .data = &sun50i_h616_rtc_ccu_data, + }, + { + .compatible = "allwinner,sun50i-r329-rtc", + .data = &sun50i_r329_rtc_ccu_data, + }, + {}, +}; + +int sun6i_rtc_ccu_probe(struct device *dev, void __iomem *reg) +{ + const struct sun6i_rtc_match_data *data; + struct clk *ext_osc32k_clk = NULL; + const struct of_device_id *match; + + /* This driver is only used for newer variants of the hardware. */ + match = of_match_device(sun6i_rtc_ccu_match, dev); + if (!match) + return 0; + + data = match->data; + have_iosc_calibration = data->have_iosc_calibration; + + if (data->have_ext_osc32k) { + const char *fw_name; + + /* ext-osc32k was the only input clock in the old binding. */ + fw_name = of_property_read_bool(dev->of_node, "clock-names") + ? "ext-osc32k" : NULL; + ext_osc32k_clk = devm_clk_get_optional(dev, fw_name); + if (IS_ERR(ext_osc32k_clk)) + return PTR_ERR(ext_osc32k_clk); + } + + if (ext_osc32k_clk) { + /* Link ext-osc32k-gate to its parent. */ + *ext_osc32k = __clk_get_hw(ext_osc32k_clk); + } else { + /* ext-osc32k-gate is an orphan, so do not register it. */ + sun6i_rtc_ccu_hw_clks.hws[CLK_EXT_OSC32K_GATE] = NULL; + osc32k_init_data.num_parents = 1; + } + + if (data->rtc_32k_single_parent) + rtc_32k_init_data.num_parents = 1; + + osc32k_fanout_init_data.parent_data = data->osc32k_fanout_parents; + osc32k_fanout_init_data.num_parents = data->osc32k_fanout_nparents; + + return devm_sunxi_ccu_probe(dev, reg, &sun6i_rtc_ccu_desc); +} + +MODULE_IMPORT_NS(SUNXI_CCU); +MODULE_LICENSE("GPL"); |