diff options
Diffstat (limited to 'drivers/memory/pl353-smc.c')
| -rw-r--r-- | drivers/memory/pl353-smc.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/drivers/memory/pl353-smc.c b/drivers/memory/pl353-smc.c new file mode 100644 index 000000000..d39ee7d06 --- /dev/null +++ b/drivers/memory/pl353-smc.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM PL353 SMC driver + * + * Copyright (C) 2012 - 2018 Xilinx, Inc + * Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com> + * Author: Naga Sureshkumar Relli <nagasure@xilinx.com> + */ + +#include <linux/clk.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/amba/bus.h> + +/** + * struct pl353_smc_data - Private smc driver structure + * @memclk: Pointer to the peripheral clock + * @aclk: Pointer to the AXI peripheral clock + */ +struct pl353_smc_data { + struct clk *memclk; + struct clk *aclk; +}; + +static int __maybe_unused pl353_smc_suspend(struct device *dev) +{ + struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev); + + clk_disable(pl353_smc->memclk); + clk_disable(pl353_smc->aclk); + + return 0; +} + +static int __maybe_unused pl353_smc_resume(struct device *dev) +{ + struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev); + int ret; + + ret = clk_enable(pl353_smc->aclk); + if (ret) { + dev_err(dev, "Cannot enable axi domain clock.\n"); + return ret; + } + + ret = clk_enable(pl353_smc->memclk); + if (ret) { + dev_err(dev, "Cannot enable memory clock.\n"); + clk_disable(pl353_smc->aclk); + return ret; + } + + return ret; +} + +static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend, + pl353_smc_resume); + +static const struct of_device_id pl353_smc_supported_children[] = { + { + .compatible = "cfi-flash" + }, + { + .compatible = "arm,pl353-nand-r2p1", + }, + {} +}; + +static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id) +{ + struct device_node *of_node = adev->dev.of_node; + const struct of_device_id *match = NULL; + struct pl353_smc_data *pl353_smc; + struct device_node *child; + int err; + + pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL); + if (!pl353_smc) + return -ENOMEM; + + pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk"); + if (IS_ERR(pl353_smc->aclk)) { + dev_err(&adev->dev, "aclk clock not found.\n"); + return PTR_ERR(pl353_smc->aclk); + } + + pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk"); + if (IS_ERR(pl353_smc->memclk)) { + dev_err(&adev->dev, "memclk clock not found.\n"); + return PTR_ERR(pl353_smc->memclk); + } + + err = clk_prepare_enable(pl353_smc->aclk); + if (err) { + dev_err(&adev->dev, "Unable to enable AXI clock.\n"); + return err; + } + + err = clk_prepare_enable(pl353_smc->memclk); + if (err) { + dev_err(&adev->dev, "Unable to enable memory clock.\n"); + goto disable_axi_clk; + } + + amba_set_drvdata(adev, pl353_smc); + + /* Find compatible children. Only a single child is supported */ + for_each_available_child_of_node(of_node, child) { + match = of_match_node(pl353_smc_supported_children, child); + if (!match) { + dev_warn(&adev->dev, "unsupported child node\n"); + continue; + } + break; + } + if (!match) { + err = -ENODEV; + dev_err(&adev->dev, "no matching children\n"); + goto disable_mem_clk; + } + + of_platform_device_create(child, NULL, &adev->dev); + of_node_put(child); + + return 0; + +disable_mem_clk: + clk_disable_unprepare(pl353_smc->memclk); +disable_axi_clk: + clk_disable_unprepare(pl353_smc->aclk); + + return err; +} + +static void pl353_smc_remove(struct amba_device *adev) +{ + struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev); + + clk_disable_unprepare(pl353_smc->memclk); + clk_disable_unprepare(pl353_smc->aclk); +} + +static const struct amba_id pl353_ids[] = { + { + .id = 0x00041353, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; +MODULE_DEVICE_TABLE(amba, pl353_ids); + +static struct amba_driver pl353_smc_driver = { + .drv = { + .owner = THIS_MODULE, + .name = "pl353-smc", + .pm = &pl353_smc_dev_pm_ops, + }, + .id_table = pl353_ids, + .probe = pl353_smc_probe, + .remove = pl353_smc_remove, +}; + +module_amba_driver(pl353_smc_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("ARM PL353 SMC Driver"); +MODULE_LICENSE("GPL"); |