diff options
Diffstat (limited to 'drivers/reset/reset-hsdk.c')
| -rw-r--r-- | drivers/reset/reset-hsdk.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/reset/reset-hsdk.c b/drivers/reset/reset-hsdk.c new file mode 100644 index 000000000..8bce391c6 --- /dev/null +++ b/drivers/reset/reset-hsdk.c @@ -0,0 +1,137 @@ +/* + * Copyright (C) 2017 Synopsys. + * + * Synopsys HSDK Development platform reset driver. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define to_hsdk_rst(p) container_of((p), struct hsdk_rst, rcdev) + +struct hsdk_rst { + void __iomem *regs_ctl; + void __iomem *regs_rst; + spinlock_t lock; + struct reset_controller_dev rcdev; +}; + +static const u32 rst_map[] = { + BIT(16), /* APB_RST */ + BIT(17), /* AXI_RST */ + BIT(18), /* ETH_RST */ + BIT(19), /* USB_RST */ + BIT(20), /* SDIO_RST */ + BIT(21), /* HDMI_RST */ + BIT(22), /* GFX_RST */ + BIT(25), /* DMAC_RST */ + BIT(31), /* EBI_RST */ +}; + +#define HSDK_MAX_RESETS ARRAY_SIZE(rst_map) + +#define CGU_SYS_RST_CTRL 0x0 +#define CGU_IP_SW_RESET 0x0 +#define CGU_IP_SW_RESET_DELAY_SHIFT 16 +#define CGU_IP_SW_RESET_DELAY_MASK GENMASK(31, CGU_IP_SW_RESET_DELAY_SHIFT) +#define CGU_IP_SW_RESET_DELAY 0 +#define CGU_IP_SW_RESET_RESET BIT(0) +#define SW_RESET_TIMEOUT 10000 + +static void hsdk_reset_config(struct hsdk_rst *rst, unsigned long id) +{ + writel(rst_map[id], rst->regs_ctl + CGU_SYS_RST_CTRL); +} + +static int hsdk_reset_do(struct hsdk_rst *rst) +{ + u32 reg; + + reg = readl(rst->regs_rst + CGU_IP_SW_RESET); + reg &= ~CGU_IP_SW_RESET_DELAY_MASK; + reg |= CGU_IP_SW_RESET_DELAY << CGU_IP_SW_RESET_DELAY_SHIFT; + reg |= CGU_IP_SW_RESET_RESET; + writel(reg, rst->regs_rst + CGU_IP_SW_RESET); + + /* wait till reset bit is back to 0 */ + return readl_poll_timeout_atomic(rst->regs_rst + CGU_IP_SW_RESET, reg, + !(reg & CGU_IP_SW_RESET_RESET), 5, SW_RESET_TIMEOUT); +} + +static int hsdk_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct hsdk_rst *rst = to_hsdk_rst(rcdev); + unsigned long flags; + int ret; + + spin_lock_irqsave(&rst->lock, flags); + hsdk_reset_config(rst, id); + ret = hsdk_reset_do(rst); + spin_unlock_irqrestore(&rst->lock, flags); + + return ret; +} + +static const struct reset_control_ops hsdk_reset_ops = { + .reset = hsdk_reset_reset, +}; + +static int hsdk_reset_probe(struct platform_device *pdev) +{ + struct hsdk_rst *rst; + struct resource *mem; + + rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL); + if (!rst) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + rst->regs_ctl = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(rst->regs_ctl)) + return PTR_ERR(rst->regs_ctl); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); + rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(rst->regs_rst)) + return PTR_ERR(rst->regs_rst); + + spin_lock_init(&rst->lock); + + rst->rcdev.owner = THIS_MODULE; + rst->rcdev.ops = &hsdk_reset_ops; + rst->rcdev.of_node = pdev->dev.of_node; + rst->rcdev.nr_resets = HSDK_MAX_RESETS; + rst->rcdev.of_reset_n_cells = 1; + + return reset_controller_register(&rst->rcdev); +} + +static const struct of_device_id hsdk_reset_dt_match[] = { + { .compatible = "snps,hsdk-reset" }, + { }, +}; + +static struct platform_driver hsdk_reset_driver = { + .probe = hsdk_reset_probe, + .driver = { + .name = "hsdk-reset", + .of_match_table = hsdk_reset_dt_match, + }, +}; +builtin_platform_driver(hsdk_reset_driver); + +MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>"); +MODULE_DESCRIPTION("Synopsys HSDK SDP reset driver"); +MODULE_LICENSE("GPL v2"); |