diff options
Diffstat (limited to 'drivers/clk/mvebu/ap806-system-controller.c')
| -rw-r--r-- | drivers/clk/mvebu/ap806-system-controller.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/clk/mvebu/ap806-system-controller.c b/drivers/clk/mvebu/ap806-system-controller.c new file mode 100644 index 000000000000..02023baf86c9 --- /dev/null +++ b/drivers/clk/mvebu/ap806-system-controller.c @@ -0,0 +1,168 @@ +/* + * Marvell Armada AP806 System Controller + * + * Copyright (C) 2016 Marvell + * + * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + * + * 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. + */ + +#define pr_fmt(fmt) "ap806-system-controller: " fmt + +#include <linux/clk-provider.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define AP806_SAR_REG 0x400 +#define AP806_SAR_CLKFREQ_MODE_MASK 0x1f + +#define AP806_CLK_NUM 4 + +static struct clk *ap806_clks[AP806_CLK_NUM]; + +static struct clk_onecell_data ap806_clk_data = { + .clks = ap806_clks, + .clk_num = AP806_CLK_NUM, +}; + +static int ap806_syscon_clk_probe(struct platform_device *pdev) +{ + unsigned int freq_mode, cpuclk_freq; + const char *name, *fixedclk_name; + struct device_node *np = pdev->dev.of_node; + struct regmap *regmap; + u32 reg; + int ret; + + regmap = syscon_node_to_regmap(np); + if (IS_ERR(regmap)) { + dev_err(&pdev->dev, "cannot get regmap\n"); + return PTR_ERR(regmap); + } + + ret = regmap_read(regmap, AP806_SAR_REG, ®); + if (ret) { + dev_err(&pdev->dev, "cannot read from regmap\n"); + return ret; + } + + freq_mode = reg & AP806_SAR_CLKFREQ_MODE_MASK; + switch (freq_mode) { + case 0x0 ... 0x5: + cpuclk_freq = 2000; + break; + case 0x6 ... 0xB: + cpuclk_freq = 1800; + break; + case 0xC ... 0x11: + cpuclk_freq = 1600; + break; + case 0x12 ... 0x16: + cpuclk_freq = 1400; + break; + case 0x17 ... 0x19: + cpuclk_freq = 1300; + break; + default: + dev_err(&pdev->dev, "invalid SAR value\n"); + return -EINVAL; + } + + /* Convert to hertz */ + cpuclk_freq *= 1000 * 1000; + + /* CPU clocks depend on the Sample At Reset configuration */ + of_property_read_string_index(np, "clock-output-names", + 0, &name); + ap806_clks[0] = clk_register_fixed_rate(&pdev->dev, name, NULL, + 0, cpuclk_freq); + if (IS_ERR(ap806_clks[0])) { + ret = PTR_ERR(ap806_clks[0]); + goto fail0; + } + + of_property_read_string_index(np, "clock-output-names", + 1, &name); + ap806_clks[1] = clk_register_fixed_rate(&pdev->dev, name, NULL, 0, + cpuclk_freq); + if (IS_ERR(ap806_clks[1])) { + ret = PTR_ERR(ap806_clks[1]); + goto fail1; + } + + /* Fixed clock is always 1200 Mhz */ + of_property_read_string_index(np, "clock-output-names", + 2, &fixedclk_name); + ap806_clks[2] = clk_register_fixed_rate(&pdev->dev, fixedclk_name, NULL, + 0, 1200 * 1000 * 1000); + if (IS_ERR(ap806_clks[2])) { + ret = PTR_ERR(ap806_clks[2]); + goto fail2; + } + + /* MSS Clock is fixed clock divided by 6 */ + of_property_read_string_index(np, "clock-output-names", + 3, &name); + ap806_clks[3] = clk_register_fixed_factor(NULL, name, fixedclk_name, + 0, 1, 6); + if (IS_ERR(ap806_clks[3])) { + ret = PTR_ERR(ap806_clks[3]); + goto fail3; + } + + ret = of_clk_add_provider(np, of_clk_src_onecell_get, &ap806_clk_data); + if (ret) + goto fail_clk_add; + + return 0; + +fail_clk_add: + clk_unregister_fixed_factor(ap806_clks[3]); +fail3: + clk_unregister_fixed_rate(ap806_clks[2]); +fail2: + clk_unregister_fixed_rate(ap806_clks[1]); +fail1: + clk_unregister_fixed_rate(ap806_clks[0]); +fail0: + return ret; +} + +static int ap806_syscon_clk_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + clk_unregister_fixed_factor(ap806_clks[3]); + clk_unregister_fixed_rate(ap806_clks[2]); + clk_unregister_fixed_rate(ap806_clks[1]); + clk_unregister_fixed_rate(ap806_clks[0]); + + return 0; +} + +static const struct of_device_id ap806_syscon_of_match[] = { + { .compatible = "marvell,ap806-system-controller", }, + { } +}; +MODULE_DEVICE_TABLE(of, armada8k_pcie_of_match); + +static struct platform_driver ap806_syscon_driver = { + .probe = ap806_syscon_clk_probe, + .remove = ap806_syscon_clk_remove, + .driver = { + .name = "marvell-ap806-system-controller", + .of_match_table = ap806_syscon_of_match, + }, +}; + +module_platform_driver(ap806_syscon_driver); + +MODULE_DESCRIPTION("Marvell AP806 System Controller driver"); +MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>"); +MODULE_LICENSE("GPL"); |