From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Add a memory-controller driver for the bcm2835 SOC.
This is mostly needed to claim the SDRAM clocks
so that this (and the corresponding parent pll)
never gets disabled.
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Changelog:
V1->V2: moved to different register sets (that are also
set up by the alternative boot loader to enable sdram)
added 2 distinct clocks (for low voltage and internal pll)
made the use of "names" for reg and clocks
---
drivers/memory/Kconfig | 7 +++
drivers/memory/Makefile | 1 +
drivers/memory/bcm2835-sdram.c | 128 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 136 insertions(+)
create mode 100644 drivers/memory/bcm2835-sdram.c
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 51d5cd2..a55cad3 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -25,6 +25,13 @@ config ATMEL_SDRAMC
Starting with the at91sam9g45, this controller supports SDR, DDR and
LP-DDR memories.
+config BCM2835_SDRAM
+ bool "Broadcom BCM2835 SDRAM Controller"
+ default y
+ depends on ARCH_BCM2835 || COMPILE_TEST
+ help
+ This driver is for Broadcom BCM2835 SDRAM Controller.
+
config TI_AEMIF
tristate "Texas Instruments AEMIF driver"
depends on (ARCH_DAVINCI || ARCH_KEYSTONE) && OF
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 890bdf4..1287b90 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_OF) += of_memory.o
endif
obj-$(CONFIG_ARM_PL172_MPMC) += pl172.o
obj-$(CONFIG_ATMEL_SDRAMC) += atmel-sdramc.o
+obj-$(CONFIG_BCM2835_SDRAM) += bcm2835-sdram.o
obj-$(CONFIG_TI_AEMIF) += ti-aemif.o
obj-$(CONFIG_TI_EMIF) += emif.o
obj-$(CONFIG_OMAP_GPMC) += omap-gpmc.o
diff --git a/drivers/memory/bcm2835-sdram.c b/drivers/memory/bcm2835-sdram.c
new file mode 100644
index 0000000..ce985ee
--- /dev/null
+++ b/drivers/memory/bcm2835-sdram.c
@@ -0,0 +1,128 @@
+/*
+ * Driver for Broadcom BCM2835 soc sdram controller
+ *
+ * Copyright (C) 2016 Martin Sperl
+ *
+ * inspired by: atmel-sdramc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+struct bcm2835_sdram_data {
+ void __iomem *sdram_regs;
+ void __iomem *aphy_csr_regs;
+ void __iomem *dphy_csr_regs;
+
+ struct clk *clk_lv;
+ struct clk *clk_pll_parent;
+};
+
+static int bcm2835_sdram_probe_reg(struct platform_device *pdev,
+ const char *name,
+ void __iomem **ptr)
+{
+ struct resource *res;
+ int err = 0;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+ if (!res) {
+ dev_err(&pdev->dev,
+ "Could not find register range %s\n",
+ name);
+ return -EINVAL;
+ }
+
+ *ptr = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(*ptr)) {
+ err = PTR_ERR(*ptr);
+ dev_err(&pdev->dev,
+ "Could not get register range %s: %d\n",
+ name, err);
+ }
+
+ return err;
+}
+
+static int bcm2835_sdram_probe(struct platform_device *pdev)
+{
+ struct bcm2835_sdram_data *data;
+ int ret;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, data);
+
+ /* get registers */
+ ret = bcm2835_sdram_probe_reg(pdev, "sdram",
+ &data->sdram_regs);
+ if (ret)
+ return ret;
+ ret = bcm2835_sdram_probe_reg(pdev, "aphy_csr",
+ &data->aphy_csr_regs);
+ if (ret)
+ return ret;
+ ret = bcm2835_sdram_probe_reg(pdev, "dphy_csr",
+ &data->dphy_csr_regs);
+ if (ret)
+ return ret;
+
+ /* get clocks */
+ data->clk_lv = devm_clk_get(&pdev->dev, "low-voltage");
+ if (IS_ERR(data->clk_lv)) {
+ ret = PTR_ERR(data->clk_lv);
+ dev_err(&pdev->dev, "Could not get clock named %s - %d\n",
+ "low-voltage", ret);
+ return ret;
+ }
+ data->clk_pll_parent = devm_clk_get(&pdev->dev, "pll-parent");
+ if (IS_ERR(data->clk_pll_parent)) {
+ ret = PTR_ERR(data->clk_pll_parent);
+ dev_err(&pdev->dev, "Could not get clock named %s - %d\n",
+ "pll-parent", ret);
+ return ret;
+ }
+
+ /* finally prepare both */
+ clk_prepare_enable(data->clk_lv);
+ clk_prepare_enable(data->clk_pll_parent);
+
+ return 0;
+}
+
+static const struct of_device_id bcm2835_sdram_of_match_table[] = {
+ { .compatible = "brcm,bcm2835-sdram", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_sdram_of_match_table);
+
+static struct platform_driver bcm2835_sdram_driver = {
+ .probe = bcm2835_sdram_probe,
+ .driver = {
+ .name = "bcm2835_sdram",
+ .of_match_table = bcm2835_sdram_of_match_table,
+ },
+};
+module_platform_driver(bcm2835_sdram_driver);
+
+MODULE_AUTHOR("Martin Sperl");
+MODULE_DESCRIPTION("sdram driver for bcm2835 chip");
+MODULE_LICENSE("GPL");
--
2.1.4
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