[PATCH 3/3] memory: Add Broadcom STB memory controller driver
Florian Fainelli
f.fainelli at gmail.com
Fri Jul 22 11:41:38 PDT 2022
Add support for configuring the Self Refresh Power Down (SRPD)
inactivity timeout on Broadcom STB chips. This is used to conserve power
when the DRAM activity is reduced.
Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
---
drivers/memory/Kconfig | 9 +
drivers/memory/Makefile | 1 +
drivers/memory/brcmstb_memc.c | 304 ++++++++++++++++++++++++++++++++++
3 files changed, 314 insertions(+)
create mode 100644 drivers/memory/brcmstb_memc.c
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index ac1a411648d8..fac290e48e0b 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -66,6 +66,15 @@ config BRCMSTB_DPFE
for the DRAM's temperature. Slower refresh rate means cooler RAM,
higher refresh rate means hotter RAM.
+config BRCMSTB_MEMC
+ tristate "Broadcom STB MEMC driver"
+ default ARCH_BRCMSTB
+ depends on ARCH_BRCMSTB || COMPILE_TEST
+ help
+ This driver provides a way to configure the Broadcom STB memory
+ controller and specifically control the Self Refresh Power Down
+ (SRPD) inactivity timeout.
+
config BT1_L2_CTL
bool "Baikal-T1 CM2 L2-RAM Cache Control Block"
depends on MIPS_BAIKAL_T1 || COMPILE_TEST
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index bc7663ed1c25..e148f636c082 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_ARM_PL172_MPMC) += pl172.o
obj-$(CONFIG_ATMEL_SDRAMC) += atmel-sdramc.o
obj-$(CONFIG_ATMEL_EBI) += atmel-ebi.o
obj-$(CONFIG_BRCMSTB_DPFE) += brcmstb_dpfe.o
+obj-$(CONFIG_BRCMSTB_MEMC) += brcmstb_memc.o
obj-$(CONFIG_BT1_L2_CTL) += bt1-l2-ctl.o
obj-$(CONFIG_TI_AEMIF) += ti-aemif.o
obj-$(CONFIG_TI_EMIF) += emif.o
diff --git a/drivers/memory/brcmstb_memc.c b/drivers/memory/brcmstb_memc.c
new file mode 100644
index 000000000000..881da958c542
--- /dev/null
+++ b/drivers/memory/brcmstb_memc.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DDR Self-Refresh Power Down (SRPD) support for Broadcom STB SoCs
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/io.h>
+
+#define REG_MEMC_CNTRLR_CONFIG 0x00
+#define CNTRLR_CONFIG_LPDDR4 5
+#define CNTRLR_CONFIG_MASK 0xf
+#define REG_MEMC_SRPD_CFG_21 0x20
+#define REG_MEMC_SRPD_CFG_20 0x34
+#define REG_MEMC_SRPD_CFG_1x 0x3c
+#define INACT_COUNT_SHIFT 0
+#define INACT_COUNT_MASK 0xffff
+#define SRPD_EN_SHIFT 16
+
+struct brcmstb_memc_data {
+ u32 srpd_offset;
+};
+
+struct brcmstb_memc {
+ struct device *dev;
+ void __iomem *ddr_ctrl;
+ unsigned int timeout_cycles;
+ u32 frequency;
+ u32 srpd_offset;
+};
+
+static int brcmstb_memc_uses_lpddr4(struct brcmstb_memc *memc)
+{
+ void __iomem *config = memc->ddr_ctrl + REG_MEMC_CNTRLR_CONFIG;
+ u32 reg;
+
+ reg = readl_relaxed(config) & CNTRLR_CONFIG_MASK;
+
+ return reg == CNTRLR_CONFIG_LPDDR4;
+}
+
+static int brcmstb_memc_srpd_config(struct brcmstb_memc *memc,
+ unsigned int cycles)
+{
+ void __iomem *cfg = memc->ddr_ctrl + memc->srpd_offset;
+ u32 val;
+
+ /* Max timeout supported in HW */
+ if (cycles > INACT_COUNT_MASK)
+ return -EINVAL;
+
+ memc->timeout_cycles = cycles;
+
+ val = (cycles << INACT_COUNT_SHIFT) & INACT_COUNT_MASK;
+ if (cycles)
+ val |= (1 << SRPD_EN_SHIFT);
+
+ writel_relaxed(val, cfg);
+ (void)readl_relaxed(cfg);
+
+ return 0;
+}
+
+static ssize_t frequency_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", memc->frequency);
+}
+
+static ssize_t srpd_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", memc->timeout_cycles);
+}
+
+static ssize_t srpd_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ unsigned int val;
+ int ret;
+
+ /* Cannot change the inactivity timeout on LPDDR4 chips because the
+ * dynamic tuning process will also get affected by the inactivity
+ * timeout, thus making it non functional.
+ */
+ if (brcmstb_memc_uses_lpddr4(memc))
+ return -EOPNOTSUPP;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = brcmstb_memc_srpd_config(memc, val);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static DEVICE_ATTR_RO(frequency);
+static DEVICE_ATTR_RW(srpd);
+
+static struct attribute *dev_attrs[] = {
+ &dev_attr_frequency.attr,
+ &dev_attr_srpd.attr,
+ NULL,
+};
+
+static struct attribute_group dev_attr_group = {
+ .attrs = dev_attrs,
+};
+
+static const struct of_device_id brcmstb_memc_of_match[];
+
+static int brcmstb_memc_probe(struct platform_device *pdev)
+{
+ const struct brcmstb_memc_data *memc_data;
+ const struct of_device_id *of_id;
+ struct device *dev = &pdev->dev;
+ struct brcmstb_memc *memc;
+ struct resource *res;
+ int ret;
+
+ memc = devm_kzalloc(dev, sizeof(*memc), GFP_KERNEL);
+ if (!memc)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, memc);
+
+ of_id = of_match_device(brcmstb_memc_of_match, dev);
+ if (!of_id || !of_id->data)
+ return -EINVAL;
+
+ memc_data = of_id->data;
+ memc->srpd_offset = memc_data->srpd_offset;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ memc->ddr_ctrl = devm_ioremap_resource(dev, res);
+ if (IS_ERR(memc->ddr_ctrl))
+ return PTR_ERR(memc->ddr_ctrl);
+
+ of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+ &memc->frequency);
+
+ ret = sysfs_create_group(&dev->kobj, &dev_attr_group);
+ if (ret) {
+ dev_err(dev, "failed to create attribute group (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int brcmstb_memc_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+
+ sysfs_remove_group(&dev->kobj, &dev_attr_group);
+
+ return 0;
+}
+
+enum brcmstb_memc_hwtype {
+ BRCMSTB_MEMC_V21,
+ BRCMSTB_MEMC_V20,
+ BRCMSTB_MEMC_V1X,
+};
+
+static const struct brcmstb_memc_data brcmstb_memc_versions[] = {
+ { .srpd_offset = REG_MEMC_SRPD_CFG_21 },
+ { .srpd_offset = REG_MEMC_SRPD_CFG_20 },
+ { .srpd_offset = REG_MEMC_SRPD_CFG_1x },
+};
+
+static const struct of_device_id brcmstb_memc_of_match[] = {
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.1.x",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V1X]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.0",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V20]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.1",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.2",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.3",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.5",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.6",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.7",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.8",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.3.0",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-b.3.1",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-c.1.0",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-c.1.1",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-c.1.2",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-c.1.3",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ {
+ .compatible = "brcm,brcmstb-memc-ddr-rev-c.1.4",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V21]
+ },
+ /* default to the original offset */
+ {
+ .compatible = "brcm,brcmstb-memc-ddr",
+ .data = &brcmstb_memc_versions[BRCMSTB_MEMC_V1X]
+ },
+ {}
+};
+
+static int __maybe_unused brcmstb_memc_suspend(struct device *dev)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ void __iomem *cfg = memc->ddr_ctrl + memc->srpd_offset;
+ u32 val;
+
+ if (memc->timeout_cycles == 0)
+ return 0;
+
+ /* Disable SPRD prior to suspending the system since that can
+ * cause issues with e.g: XPT_DMA trying to hash memory
+ */
+ val = readl_relaxed(cfg);
+ val &= ~(1 << SRPD_EN_SHIFT);
+ writel_relaxed(val, cfg);
+ (void)readl_relaxed(cfg);
+
+ return 0;
+}
+
+static int __maybe_unused brcmstb_memc_resume(struct device *dev)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+
+ if (memc->timeout_cycles == 0)
+ return 0;
+
+ return brcmstb_memc_srpd_config(memc, memc->timeout_cycles);
+}
+
+static SIMPLE_DEV_PM_OPS(brcmstb_memc_pm_ops, brcmstb_memc_suspend,
+ brcmstb_memc_resume);
+
+static struct platform_driver brcmstb_memc_driver = {
+ .probe = brcmstb_memc_probe,
+ .remove = brcmstb_memc_remove,
+ .driver = {
+ .name = "brcmstb_memc",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(brcmstb_memc_of_match),
+ .pm = &brcmstb_memc_pm_ops,
+ },
+};
+module_platform_driver(brcmstb_memc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("DDR SRPD driver for Broadcom STB chips");
--
2.25.1
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