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-rw-r--r--drivers/clk/tegra/Makefile1
-rw-r--r--drivers/clk/tegra/clk-tegra210-emc.c369
-rw-r--r--drivers/clk/tegra/clk.h3
-rw-r--r--include/linux/clk/tegra.h24
4 files changed, 397 insertions, 0 deletions
diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
index 7f5f5ec33739..6e1200b3bb68 100644
--- a/drivers/clk/tegra/Makefile
+++ b/drivers/clk/tegra/Makefile
@@ -25,5 +25,6 @@ obj-$(CONFIG_TEGRA124_EMC) += clk-tegra124-emc.o
obj-$(CONFIG_ARCH_TEGRA_132_SOC) += clk-tegra124.o
obj-y += cvb.o
obj-$(CONFIG_ARCH_TEGRA_210_SOC) += clk-tegra210.o
+obj-$(CONFIG_ARCH_TEGRA_210_SOC) += clk-tegra210-emc.o
obj-$(CONFIG_CLK_TEGRA_BPMP) += clk-bpmp.o
obj-y += clk-utils.o
diff --git a/drivers/clk/tegra/clk-tegra210-emc.c b/drivers/clk/tegra/clk-tegra210-emc.c
new file mode 100644
index 000000000000..352a2c3fc374
--- /dev/null
+++ b/drivers/clk/tegra/clk-tegra210-emc.c
@@ -0,0 +1,369 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015-2020, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/tegra.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define CLK_SOURCE_EMC 0x19c
+#define CLK_SOURCE_EMC_2X_CLK_SRC GENMASK(31, 29)
+#define CLK_SOURCE_EMC_MC_EMC_SAME_FREQ BIT(16)
+#define CLK_SOURCE_EMC_2X_CLK_DIVISOR GENMASK(7, 0)
+
+#define CLK_SRC_PLLM 0
+#define CLK_SRC_PLLC 1
+#define CLK_SRC_PLLP 2
+#define CLK_SRC_CLK_M 3
+#define CLK_SRC_PLLM_UD 4
+#define CLK_SRC_PLLMB_UD 5
+#define CLK_SRC_PLLMB 6
+#define CLK_SRC_PLLP_UD 7
+
+struct tegra210_clk_emc {
+ struct clk_hw hw;
+ void __iomem *regs;
+
+ struct tegra210_clk_emc_provider *provider;
+
+ struct clk *parents[8];
+};
+
+static inline struct tegra210_clk_emc *
+to_tegra210_clk_emc(struct clk_hw *hw)
+{
+ return container_of(hw, struct tegra210_clk_emc, hw);
+}
+
+static const char *tegra210_clk_emc_parents[] = {
+ "pll_m", "pll_c", "pll_p", "clk_m", "pll_m_ud", "pll_mb_ud",
+ "pll_mb", "pll_p_ud",
+};
+
+static u8 tegra210_clk_emc_get_parent(struct clk_hw *hw)
+{
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
+ u32 value;
+ u8 src;
+
+ value = readl_relaxed(emc->regs + CLK_SOURCE_EMC);
+ src = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_SRC, value);
+
+ return src;
+}
+
+static unsigned long tegra210_clk_emc_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
+ u32 value, div;
+
+ /*
+ * CCF assumes that neither the parent nor its rate will change during
+ * ->set_rate(), so the parent rate passed in here was cached from the
+ * parent before the ->set_rate() call.
+ *
+ * This can lead to wrong results being reported for the EMC clock if
+ * the parent and/or parent rate have changed as part of the EMC rate
+ * change sequence. Fix this by overriding the parent clock with what
+ * we know to be the correct value after the rate change.
+ */
+ parent_rate = clk_hw_get_rate(clk_hw_get_parent(hw));
+
+ value = readl_relaxed(emc->regs + CLK_SOURCE_EMC);
+
+ div = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_DIVISOR, value);
+ div += 2;
+
+ return DIV_ROUND_UP(parent_rate * 2, div);
+}
+
+static long tegra210_clk_emc_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
+ struct tegra210_clk_emc_provider *provider = emc->provider;
+ unsigned int i;
+
+ if (!provider || !provider->configs || provider->num_configs == 0)
+ return clk_hw_get_rate(hw);
+
+ for (i = 0; i < provider->num_configs; i++) {
+ if (provider->configs[i].rate >= rate)
+ return provider->configs[i].rate;
+ }
+
+ return provider->configs[i - 1].rate;
+}
+
+static struct clk *tegra210_clk_emc_find_parent(struct tegra210_clk_emc *emc,
+ u8 index)
+{
+ struct clk_hw *parent = clk_hw_get_parent_by_index(&emc->hw, index);
+ const char *name = clk_hw_get_name(parent);
+
+ /* XXX implement cache? */
+
+ return __clk_lookup(name);
+}
+
+static int tegra210_clk_emc_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
+ struct tegra210_clk_emc_provider *provider = emc->provider;
+ struct tegra210_clk_emc_config *config;
+ struct device *dev = provider->dev;
+ struct clk_hw *old, *new, *parent;
+ u8 old_idx, new_idx, index;
+ struct clk *clk;
+ unsigned int i;
+ int err;
+
+ if (!provider || !provider->configs || provider->num_configs == 0)
+ return -EINVAL;
+
+ for (i = 0; i < provider->num_configs; i++) {
+ if (provider->configs[i].rate >= rate) {
+ config = &provider->configs[i];
+ break;
+ }
+ }
+
+ if (i == provider->num_configs)
+ config = &provider->configs[i - 1];
+
+ old_idx = tegra210_clk_emc_get_parent(hw);
+ new_idx = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_SRC, config->value);
+
+ old = clk_hw_get_parent_by_index(hw, old_idx);
+ new = clk_hw_get_parent_by_index(hw, new_idx);
+
+ /* if the rate has changed... */
+ if (config->parent_rate != clk_hw_get_rate(old)) {
+ /* ... but the clock source remains the same ... */
+ if (new_idx == old_idx) {
+ /* ... switch to the alternative clock source. */
+ switch (new_idx) {
+ case CLK_SRC_PLLM:
+ new_idx = CLK_SRC_PLLMB;
+ break;
+
+ case CLK_SRC_PLLM_UD:
+ new_idx = CLK_SRC_PLLMB_UD;
+ break;
+
+ case CLK_SRC_PLLMB_UD:
+ new_idx = CLK_SRC_PLLM_UD;
+ break;
+
+ case CLK_SRC_PLLMB:
+ new_idx = CLK_SRC_PLLM;
+ break;
+ }
+
+ /*
+ * This should never happen because we can't deal with
+ * it.
+ */
+ if (WARN_ON(new_idx == old_idx))
+ return -EINVAL;
+
+ new = clk_hw_get_parent_by_index(hw, new_idx);
+ }
+
+ index = new_idx;
+ parent = new;
+ } else {
+ index = old_idx;
+ parent = old;
+ }
+
+ clk = tegra210_clk_emc_find_parent(emc, index);
+ if (IS_ERR(clk)) {
+ err = PTR_ERR(clk);
+ dev_err(dev, "failed to get parent clock for index %u: %d\n",
+ index, err);
+ return err;
+ }
+
+ /* set the new parent clock to the required rate */
+ if (clk_get_rate(clk) != config->parent_rate) {
+ err = clk_set_rate(clk, config->parent_rate);
+ if (err < 0) {
+ dev_err(dev, "failed to set rate %lu Hz for %pC: %d\n",
+ config->parent_rate, clk, err);
+ return err;
+ }
+ }
+
+ /* enable the new parent clock */
+ if (parent != old) {
+ err = clk_prepare_enable(clk);
+ if (err < 0) {
+ dev_err(dev, "failed to enable parent clock %pC: %d\n",
+ clk, err);
+ return err;
+ }
+ }
+
+ /* update the EMC source configuration to reflect the new parent */
+ config->value &= ~CLK_SOURCE_EMC_2X_CLK_SRC;
+ config->value |= FIELD_PREP(CLK_SOURCE_EMC_2X_CLK_SRC, index);
+
+ /*
+ * Finally, switch the EMC programming with both old and new parent
+ * clocks enabled.
+ */
+ err = provider->set_rate(dev, config);
+ if (err < 0) {
+ dev_err(dev, "failed to set EMC rate to %lu Hz: %d\n", rate,
+ err);
+
+ /*
+ * If we're unable to switch to the new EMC frequency, we no
+ * longer need the new parent to be enabled.
+ */
+ if (parent != old)
+ clk_disable_unprepare(clk);
+
+ return err;
+ }
+
+ /* reparent to new parent clock and disable the old parent clock */
+ if (parent != old) {
+ clk = tegra210_clk_emc_find_parent(emc, old_idx);
+ if (IS_ERR(clk)) {
+ err = PTR_ERR(clk);
+ dev_err(dev,
+ "failed to get parent clock for index %u: %d\n",
+ old_idx, err);
+ return err;
+ }
+
+ clk_hw_reparent(hw, parent);
+ clk_disable_unprepare(clk);
+ }
+
+ return err;
+}
+
+static const struct clk_ops tegra210_clk_emc_ops = {
+ .get_parent = tegra210_clk_emc_get_parent,
+ .recalc_rate = tegra210_clk_emc_recalc_rate,
+ .round_rate = tegra210_clk_emc_round_rate,
+ .set_rate = tegra210_clk_emc_set_rate,
+};
+
+struct clk *tegra210_clk_register_emc(struct device_node *np,
+ void __iomem *regs)
+{
+ struct tegra210_clk_emc *emc;
+ struct clk_init_data init;
+ struct clk *clk;
+
+ emc = kzalloc(sizeof(*emc), GFP_KERNEL);
+ if (!emc)
+ return ERR_PTR(-ENOMEM);
+
+ emc->regs = regs;
+
+ init.name = "emc";
+ init.ops = &tegra210_clk_emc_ops;
+ init.flags = CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE;
+ init.parent_names = tegra210_clk_emc_parents;
+ init.num_parents = ARRAY_SIZE(tegra210_clk_emc_parents);
+ emc->hw.init = &init;
+
+ clk = clk_register(NULL, &emc->hw);
+ if (IS_ERR(clk)) {
+ kfree(emc);
+ return clk;
+ }
+
+ return clk;
+}
+
+int tegra210_clk_emc_attach(struct clk *clk,
+ struct tegra210_clk_emc_provider *provider)
+{
+ struct clk_hw *hw = __clk_get_hw(clk);
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
+ struct device *dev = provider->dev;
+ unsigned int i;
+ int err;
+
+ if (!try_module_get(provider->owner))
+ return -ENODEV;
+
+ for (i = 0; i < provider->num_configs; i++) {
+ struct tegra210_clk_emc_config *config = &provider->configs[i];
+ struct clk_hw *parent;
+ bool same_freq;
+ u8 div, src;
+
+ div = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_DIVISOR, config->value);
+ src = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_SRC, config->value);
+
+ /* do basic sanity checking on the EMC timings */
+ if (div & 0x1) {
+ dev_err(dev, "invalid odd divider %u for rate %lu Hz\n",
+ div, config->rate);
+ err = -EINVAL;
+ goto put;
+ }
+
+ same_freq = config->value & CLK_SOURCE_EMC_MC_EMC_SAME_FREQ;
+
+ if (same_freq != config->same_freq) {
+ dev_err(dev,
+ "ambiguous EMC to MC ratio for rate %lu Hz\n",
+ config->rate);
+ err = -EINVAL;
+ goto put;
+ }
+
+ parent = clk_hw_get_parent_by_index(hw, src);
+ config->parent = src;
+
+ if (src == CLK_SRC_PLLM || src == CLK_SRC_PLLM_UD) {
+ config->parent_rate = config->rate * (1 + div / 2);
+ } else {
+ unsigned long rate = config->rate * (1 + div / 2);
+
+ config->parent_rate = clk_hw_get_rate(parent);
+
+ if (config->parent_rate != rate) {
+ dev_err(dev,
+ "rate %lu Hz does not match input\n",
+ config->rate);
+ err = -EINVAL;
+ goto put;
+ }
+ }
+ }
+
+ emc->provider = provider;
+
+ return 0;
+
+put:
+ module_put(provider->owner);
+ return err;
+}
+EXPORT_SYMBOL_GPL(tegra210_clk_emc_attach);
+
+void tegra210_clk_emc_detach(struct clk *clk)
+{
+ struct tegra210_clk_emc *emc = to_tegra210_clk_emc(__clk_get_hw(clk));
+
+ module_put(emc->provider->owner);
+ emc->provider = NULL;
+}
+EXPORT_SYMBOL_GPL(tegra210_clk_emc_detach);
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 1d9f1bc18334..09cc700bab41 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -907,4 +907,7 @@ void tegra_clk_periph_resume(void);
bool tegra20_clk_emc_driver_available(struct clk_hw *emc_hw);
struct clk *tegra20_clk_register_emc(void __iomem *ioaddr, bool low_jitter);
+struct clk *tegra210_clk_register_emc(struct device_node *np,
+ void __iomem *regs);
+
#endif /* TEGRA_CLK_H */
diff --git a/include/linux/clk/tegra.h b/include/linux/clk/tegra.h
index 5b0bdb413460..3f01d43f0598 100644
--- a/include/linux/clk/tegra.h
+++ b/include/linux/clk/tegra.h
@@ -146,4 +146,28 @@ void tegra20_clk_set_emc_round_callback(tegra20_clk_emc_round_cb *round_cb,
void *cb_arg);
int tegra20_clk_prepare_emc_mc_same_freq(struct clk *emc_clk, bool same);
+struct tegra210_clk_emc_config {
+ unsigned long rate;
+ bool same_freq;
+ u32 value;
+
+ unsigned long parent_rate;
+ u8 parent;
+};
+
+struct tegra210_clk_emc_provider {
+ struct module *owner;
+ struct device *dev;
+
+ struct tegra210_clk_emc_config *configs;
+ unsigned int num_configs;
+
+ int (*set_rate)(struct device *dev,
+ const struct tegra210_clk_emc_config *config);
+};
+
+int tegra210_clk_emc_attach(struct clk *clk,
+ struct tegra210_clk_emc_provider *provider);
+void tegra210_clk_emc_detach(struct clk *clk);
+
#endif /* __LINUX_CLK_TEGRA_H_ */
generated by cgit (git 2.34.1) at 2024-06-23 22:12:33 +0000