From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/clk/tegra/clk-tegra20-emc.c | 296 ++++++++++++++++++++++++++++++++++++ 1 file changed, 296 insertions(+) create mode 100644 drivers/clk/tegra/clk-tegra20-emc.c (limited to 'drivers/clk/tegra/clk-tegra20-emc.c') diff --git a/drivers/clk/tegra/clk-tegra20-emc.c b/drivers/clk/tegra/clk-tegra20-emc.c new file mode 100644 index 000000000..dd74b8543 --- /dev/null +++ b/drivers/clk/tegra/clk-tegra20-emc.c @@ -0,0 +1,296 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Based on drivers/clk/tegra/clk-emc.c + * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved. + * + * Author: Dmitry Osipenko + * Copyright (C) 2019 GRATE-DRIVER project + */ + +#define pr_fmt(fmt) "tegra-emc-clk: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "clk.h" + +#define CLK_SOURCE_EMC_2X_CLK_DIVISOR_MASK GENMASK(7, 0) +#define CLK_SOURCE_EMC_2X_CLK_SRC_MASK GENMASK(31, 30) +#define CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT 30 + +#define MC_EMC_SAME_FREQ BIT(16) +#define USE_PLLM_UD BIT(29) + +#define EMC_SRC_PLL_M 0 +#define EMC_SRC_PLL_C 1 +#define EMC_SRC_PLL_P 2 +#define EMC_SRC_CLK_M 3 + +static const char * const emc_parent_clk_names[] = { + "pll_m", "pll_c", "pll_p", "clk_m", +}; + +struct tegra_clk_emc { + struct clk_hw hw; + void __iomem *reg; + bool mc_same_freq; + bool want_low_jitter; + + tegra20_clk_emc_round_cb *round_cb; + void *cb_arg; +}; + +static inline struct tegra_clk_emc *to_tegra_clk_emc(struct clk_hw *hw) +{ + return container_of(hw, struct tegra_clk_emc, hw); +} + +static unsigned long emc_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + u32 val, div; + + val = readl_relaxed(emc->reg); + div = val & CLK_SOURCE_EMC_2X_CLK_DIVISOR_MASK; + + return DIV_ROUND_UP(parent_rate * 2, div + 2); +} + +static u8 emc_get_parent(struct clk_hw *hw) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + + return readl_relaxed(emc->reg) >> CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT; +} + +static int emc_set_parent(struct clk_hw *hw, u8 index) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + u32 val, div; + + val = readl_relaxed(emc->reg); + val &= ~CLK_SOURCE_EMC_2X_CLK_SRC_MASK; + val |= index << CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT; + + div = val & CLK_SOURCE_EMC_2X_CLK_DIVISOR_MASK; + + if (index == EMC_SRC_PLL_M && div == 0 && emc->want_low_jitter) + val |= USE_PLLM_UD; + else + val &= ~USE_PLLM_UD; + + if (emc->mc_same_freq) + val |= MC_EMC_SAME_FREQ; + else + val &= ~MC_EMC_SAME_FREQ; + + writel_relaxed(val, emc->reg); + + fence_udelay(1, emc->reg); + + return 0; +} + +static int emc_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + unsigned int index; + u32 val, div; + + div = div_frac_get(rate, parent_rate, 8, 1, 0); + + val = readl_relaxed(emc->reg); + val &= ~CLK_SOURCE_EMC_2X_CLK_DIVISOR_MASK; + val |= div; + + index = val >> CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT; + + if (index == EMC_SRC_PLL_M && div == 0 && emc->want_low_jitter) + val |= USE_PLLM_UD; + else + val &= ~USE_PLLM_UD; + + if (emc->mc_same_freq) + val |= MC_EMC_SAME_FREQ; + else + val &= ~MC_EMC_SAME_FREQ; + + writel_relaxed(val, emc->reg); + + fence_udelay(1, emc->reg); + + return 0; +} + +static int emc_set_rate_and_parent(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate, + u8 index) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + u32 val, div; + + div = div_frac_get(rate, parent_rate, 8, 1, 0); + + val = readl_relaxed(emc->reg); + + val &= ~CLK_SOURCE_EMC_2X_CLK_SRC_MASK; + val |= index << CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT; + + val &= ~CLK_SOURCE_EMC_2X_CLK_DIVISOR_MASK; + val |= div; + + if (index == EMC_SRC_PLL_M && div == 0 && emc->want_low_jitter) + val |= USE_PLLM_UD; + else + val &= ~USE_PLLM_UD; + + if (emc->mc_same_freq) + val |= MC_EMC_SAME_FREQ; + else + val &= ~MC_EMC_SAME_FREQ; + + writel_relaxed(val, emc->reg); + + fence_udelay(1, emc->reg); + + return 0; +} + +static int emc_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) +{ + struct tegra_clk_emc *emc = to_tegra_clk_emc(hw); + struct clk_hw *parent_hw; + unsigned long divided_rate; + unsigned long parent_rate; + unsigned int i; + long emc_rate; + int div; + + emc_rate = emc->round_cb(req->rate, req->min_rate, req->max_rate, + emc->cb_arg); + if (emc_rate < 0) + return emc_rate; + + for (i = 0; i < ARRAY_SIZE(emc_parent_clk_names); i++) { + parent_hw = clk_hw_get_parent_by_index(hw, i); + + if (req->best_parent_hw == parent_hw) + parent_rate = req->best_parent_rate; + else + parent_rate = clk_hw_get_rate(parent_hw); + + if (emc_rate > parent_rate) + continue; + + div = div_frac_get(emc_rate, parent_rate, 8, 1, 0); + divided_rate = DIV_ROUND_UP(parent_rate * 2, div + 2); + + if (divided_rate != emc_rate) + continue; + + req->best_parent_rate = parent_rate; + req->best_parent_hw = parent_hw; + req->rate = emc_rate; + break; + } + + if (i == ARRAY_SIZE(emc_parent_clk_names)) { + pr_err_once("can't find parent for rate %lu emc_rate %lu\n", + req->rate, emc_rate); + return -EINVAL; + } + + return 0; +} + +static const struct clk_ops tegra_clk_emc_ops = { + .recalc_rate = emc_recalc_rate, + .get_parent = emc_get_parent, + .set_parent = emc_set_parent, + .set_rate = emc_set_rate, + .set_rate_and_parent = emc_set_rate_and_parent, + .determine_rate = emc_determine_rate, +}; + +void tegra20_clk_set_emc_round_callback(tegra20_clk_emc_round_cb *round_cb, + void *cb_arg) +{ + struct clk *clk = __clk_lookup("emc"); + struct tegra_clk_emc *emc; + struct clk_hw *hw; + + if (clk) { + hw = __clk_get_hw(clk); + emc = to_tegra_clk_emc(hw); + + emc->round_cb = round_cb; + emc->cb_arg = cb_arg; + } +} +EXPORT_SYMBOL_GPL(tegra20_clk_set_emc_round_callback); + +bool tegra20_clk_emc_driver_available(struct clk_hw *emc_hw) +{ + return to_tegra_clk_emc(emc_hw)->round_cb != NULL; +} + +struct clk *tegra20_clk_register_emc(void __iomem *ioaddr, bool low_jitter) +{ + struct tegra_clk_emc *emc; + struct clk_init_data init; + struct clk *clk; + + emc = kzalloc(sizeof(*emc), GFP_KERNEL); + if (!emc) + return NULL; + + /* + * EMC stands for External Memory Controller. + * + * We don't want EMC clock to be disabled ever by gating its + * parent and whatnot because system is busted immediately in that + * case, hence the clock is marked as critical. + */ + init.name = "emc"; + init.ops = &tegra_clk_emc_ops; + init.flags = CLK_IS_CRITICAL; + init.parent_names = emc_parent_clk_names; + init.num_parents = ARRAY_SIZE(emc_parent_clk_names); + + emc->reg = ioaddr; + emc->hw.init = &init; + emc->want_low_jitter = low_jitter; + + clk = clk_register(NULL, &emc->hw); + if (IS_ERR(clk)) { + kfree(emc); + return NULL; + } + + return clk; +} + +int tegra20_clk_prepare_emc_mc_same_freq(struct clk *emc_clk, bool same) +{ + struct tegra_clk_emc *emc; + struct clk_hw *hw; + + if (!emc_clk) + return -EINVAL; + + hw = __clk_get_hw(emc_clk); + emc = to_tegra_clk_emc(hw); + emc->mc_same_freq = same; + + return 0; +} +EXPORT_SYMBOL_GPL(tegra20_clk_prepare_emc_mc_same_freq); -- cgit v1.2.3