This driver binds to the memory controller hardware in Apple SoCs such
as the Apple M1, and provides a power domain that downstream devices can
use to change the performance state of the memory controller.
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/memory/Kconfig | 9 +++
drivers/memory/Makefile | 1 +
drivers/memory/apple-mcc.c | 130 +++++++++++++++++++++++++++++++++++++
3 files changed, 140 insertions(+)
create mode 100644 drivers/memory/apple-mcc.c
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 72c0df129d5c..48ef3d563a1c 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -30,6 +30,15 @@ config ARM_PL172_MPMC
If you have an embedded system with an AMBA bus and a PL172
controller, say Y or M here.
+config APPLE_MCC
+ tristate "Apple SoC MCC driver"
+ default y if ARCH_APPLE
+ select PM_GENERIC_DOMAINS
+ depends on ARCH_APPLE || COMPILE_TEST
+ help
+ This driver manages performance tuning for the memory controller in
+ Apple SoCs, such as the Apple M1.
+
config ATMEL_SDRAMC
bool "Atmel (Multi-port DDR-)SDRAM Controller"
default y if ARCH_AT91
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index bc7663ed1c25..947840cbd2d4 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -8,6 +8,7 @@ ifeq ($(CONFIG_DDR),y)
obj-$(CONFIG_OF) += of_memory.o
endif
obj-$(CONFIG_ARM_PL172_MPMC) += pl172.o
+obj-$(CONFIG_APPLE_MCC) += apple-mcc.o
obj-$(CONFIG_ATMEL_SDRAMC) += atmel-sdramc.o
obj-$(CONFIG_ATMEL_EBI) += atmel-ebi.o
obj-$(CONFIG_BRCMSTB_DPFE) += brcmstb_dpfe.o
diff --git a/drivers/memory/apple-mcc.c b/drivers/memory/apple-mcc.c
new file mode 100644
index 000000000000..55959f034b9a
--- /dev/null
+++ b/drivers/memory/apple-mcc.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SoC MCC memory controller performance control driver
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+
+#define APPLE_MCC_PERF_CONFIG1 0xdc4
+#define APPLE_MCC_PERF_CONFIG2 0xdbc
+#define APPLE_MCC_CHANNEL(x) ((x) * 0x40000)
+
+struct apple_mcc {
+ struct device *dev;
+ struct generic_pm_domain genpd;
+ void __iomem *reg_base;
+ u32 num_channels;
+};
+
+#define to_apple_mcc(_genpd) container_of(_genpd, struct apple_mcc, genpd)
+
+static int apple_mcc_set_performance_state(struct generic_pm_domain *genpd, unsigned int state)
+{
+ struct apple_mcc *mcc = to_apple_mcc(genpd);
+ struct dev_pm_opp *opp;
+ struct device_node *np;
+ u32 perf_config[2];
+ unsigned int i;
+
+ dev_dbg(mcc->dev, "switching to perf state %d\n", state);
+
+ opp = dev_pm_opp_find_level_exact(&mcc->genpd.dev, state);
+ if (IS_ERR(opp))
+ return PTR_ERR(opp);
+
+ np = dev_pm_opp_get_of_node(opp);
+ if (of_property_read_u32_array(np, "apple,memory-perf-config",
+ perf_config, ARRAY_SIZE(perf_config))) {
+ dev_err(mcc->dev, "missing apple,memory-perf-config property");
+ of_node_put(np);
+ return -EINVAL;
+ }
+ of_node_put(np);
+
+ for (i = 0; i < mcc->num_channels; i++) {
+ writel_relaxed(perf_config[0],
+ mcc->reg_base + APPLE_MCC_CHANNEL(i) + APPLE_MCC_PERF_CONFIG1);
+ writel_relaxed(perf_config[1],
+ mcc->reg_base + APPLE_MCC_CHANNEL(i) + APPLE_MCC_PERF_CONFIG2);
+ }
+
+ return 0;
+}
+
+static unsigned int apple_mcc_opp_to_performance_state(struct generic_pm_domain *genpd,
+ struct dev_pm_opp *opp)
+{
+ return dev_pm_opp_get_level(opp);
+}
+
+static int apple_mcc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct apple_mcc *mcc;
+ int ret;
+
+ mcc = devm_kzalloc(dev, sizeof(*mcc), GFP_KERNEL);
+ if (!mcc)
+ return -ENOMEM;
+
+ mcc->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(mcc->reg_base))
+ return PTR_ERR(mcc->reg_base);
+
+ if (of_property_read_u32(node, "apple,num-channels", &mcc->num_channels)) {
+ dev_err(dev, "missing apple,num-channels property\n");
+ return -ENOENT;
+ }
+
+ mcc->dev = dev;
+ mcc->genpd.name = "apple-mcc-perf";
+ mcc->genpd.opp_to_performance_state = apple_mcc_opp_to_performance_state;
+ mcc->genpd.set_performance_state = apple_mcc_set_performance_state;
+
+ ret = pm_genpd_init(&mcc->genpd, NULL, false);
+ if (ret < 0) {
+ dev_err(dev, "pm_genpd_init failed\n");
+ return ret;
+ }
+
+ ret = of_genpd_add_provider_simple_noclk(node, &mcc->genpd);
+ if (ret < 0) {
+ dev_err(dev, "of_genpd_add_provider_simple failed\n");
+ return ret;
+ }
+
+ dev_info(dev, "Apple MCC performance driver initialized\n");
+
+ return 0;
+}
+
+static const struct of_device_id apple_mcc_of_match[] = {
+ { .compatible = "apple,mcc" },
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, apple_mcc_of_match);
+
+static struct platform_driver apple_mcc_driver = {
+ .probe = apple_mcc_probe,
+ .driver = {
+ .name = "apple-mcc",
+ .of_match_table = apple_mcc_of_match,
+ },
+};
+
+MODULE_AUTHOR("Hector Martin <marcan@xxxxxxxxx>");
+MODULE_DESCRIPTION("MCC memory controller performance tuning driver for Apple SoCs");
+MODULE_LICENSE("GPL v2");
+
+module_platform_driver(apple_mcc_driver);
--
2.33.0
