diff options
Diffstat (limited to 'drivers/clk/microchip/clk-pic32mzda.c')
| -rw-r--r-- | drivers/clk/microchip/clk-pic32mzda.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/clk/microchip/clk-pic32mzda.c b/drivers/clk/microchip/clk-pic32mzda.c new file mode 100644 index 000000000000..020a29acc5b0 --- /dev/null +++ b/drivers/clk/microchip/clk-pic32mzda.c @@ -0,0 +1,275 @@ +/* + * Purna Chandra Mandal,<purna.mandal@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope 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 <dt-bindings/clock/microchip,pic32-clock.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <asm/traps.h> + +#include "clk-core.h" + +/* FRC Postscaler */ +#define OSC_FRCDIV_MASK 0x07 +#define OSC_FRCDIV_SHIFT 24 + +/* SPLL fields */ +#define PLL_ICLK_MASK 0x01 +#define PLL_ICLK_SHIFT 7 + +#define DECLARE_PERIPHERAL_CLOCK(__clk_name, __reg, __flags) \ + { \ + .ctrl_reg = (__reg), \ + .init_data = { \ + .name = (__clk_name), \ + .parent_names = (const char *[]) { \ + "sys_clk" \ + }, \ + .num_parents = 1, \ + .ops = &pic32_pbclk_ops, \ + .flags = (__flags), \ + }, \ + } + +#define DECLARE_REFO_CLOCK(__clkid, __reg) \ + { \ + .ctrl_reg = (__reg), \ + .init_data = { \ + .name = "refo" #__clkid "_clk", \ + .parent_names = (const char *[]) { \ + "sys_clk", "pb1_clk", "posc_clk", \ + "frc_clk", "lprc_clk", "sosc_clk", \ + "sys_pll", "refi" #__clkid "_clk", \ + "bfrc_clk", \ + }, \ + .num_parents = 9, \ + .flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE,\ + .ops = &pic32_roclk_ops, \ + }, \ + .parent_map = (const u32[]) { \ + 0, 1, 2, 3, 4, 5, 7, 8, 9 \ + }, \ + } + +static const struct pic32_ref_osc_data ref_clks[] = { + DECLARE_REFO_CLOCK(1, 0x80), + DECLARE_REFO_CLOCK(2, 0xa0), + DECLARE_REFO_CLOCK(3, 0xc0), + DECLARE_REFO_CLOCK(4, 0xe0), + DECLARE_REFO_CLOCK(5, 0x100), +}; + +static const struct pic32_periph_clk_data periph_clocks[] = { + DECLARE_PERIPHERAL_CLOCK("pb1_clk", 0x140, 0), + DECLARE_PERIPHERAL_CLOCK("pb2_clk", 0x150, CLK_IGNORE_UNUSED), + DECLARE_PERIPHERAL_CLOCK("pb3_clk", 0x160, 0), + DECLARE_PERIPHERAL_CLOCK("pb4_clk", 0x170, 0), + DECLARE_PERIPHERAL_CLOCK("pb5_clk", 0x180, 0), + DECLARE_PERIPHERAL_CLOCK("pb6_clk", 0x190, 0), + DECLARE_PERIPHERAL_CLOCK("cpu_clk", 0x1a0, CLK_IGNORE_UNUSED), +}; + +static const struct pic32_sys_clk_data sys_mux_clk = { + .slew_reg = 0x1c0, + .slew_div = 2, /* step of div_4 -> div_2 -> no_div */ + .init_data = { + .name = "sys_clk", + .parent_names = (const char *[]) { + "frcdiv_clk", "sys_pll", "posc_clk", + "sosc_clk", "lprc_clk", "frcdiv_clk", + }, + .num_parents = 6, + .ops = &pic32_sclk_ops, + }, + .parent_map = (const u32[]) { + 0, 1, 2, 4, 5, 7, + }, +}; + +static const struct pic32_sys_pll_data sys_pll = { + .ctrl_reg = 0x020, + .status_reg = 0x1d0, + .lock_mask = BIT(7), + .init_data = { + .name = "sys_pll", + .parent_names = (const char *[]) { + "spll_mux_clk" + }, + .num_parents = 1, + .ops = &pic32_spll_ops, + }, +}; + +static const struct pic32_sec_osc_data sosc_clk = { + .status_reg = 0x1d0, + .enable_mask = BIT(1), + .status_mask = BIT(4), + .init_data = { + .name = "sosc_clk", + .parent_names = NULL, + .ops = &pic32_sosc_ops, + }, +}; + +static int pic32mzda_critical_clks[] = { + PB2CLK, PB7CLK +}; + +/* PIC32MZDA clock data */ +struct pic32mzda_clk_data { + struct clk *clks[MAXCLKS]; + struct pic32_clk_common core; + struct clk_onecell_data onecell_data; + struct notifier_block failsafe_notifier; +}; + +static int pic32_fscm_nmi(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pic32mzda_clk_data *cd; + + cd = container_of(nb, struct pic32mzda_clk_data, failsafe_notifier); + + /* SYSCLK is now running from BFRCCLK. Report clock failure. */ + if (readl(cd->core.iobase) & BIT(2)) + pr_alert("pic32-clk: FSCM detected clk failure.\n"); + + /* TODO: detect reason of failure and recover accordingly */ + + return NOTIFY_OK; +} + +static int pic32mzda_clk_probe(struct platform_device *pdev) +{ + const char *const pll_mux_parents[] = {"posc_clk", "frc_clk"}; + struct device_node *np = pdev->dev.of_node; + struct pic32mzda_clk_data *cd; + struct pic32_clk_common *core; + struct clk *pll_mux_clk, *clk; + struct clk **clks; + int nr_clks, i, ret; + + cd = devm_kzalloc(&pdev->dev, sizeof(*cd), GFP_KERNEL); + if (!cd) + return -ENOMEM; + + core = &cd->core; + core->iobase = of_io_request_and_map(np, 0, of_node_full_name(np)); + if (IS_ERR(core->iobase)) { + dev_err(&pdev->dev, "pic32-clk: failed to map registers\n"); + return PTR_ERR(core->iobase); + } + + spin_lock_init(&core->reg_lock); + core->dev = &pdev->dev; + clks = &cd->clks[0]; + + /* register fixed rate clocks */ + clks[POSCCLK] = clk_register_fixed_rate(&pdev->dev, "posc_clk", NULL, + CLK_IS_ROOT, 24000000); + clks[FRCCLK] = clk_register_fixed_rate(&pdev->dev, "frc_clk", NULL, + CLK_IS_ROOT, 8000000); + clks[BFRCCLK] = clk_register_fixed_rate(&pdev->dev, "bfrc_clk", NULL, + CLK_IS_ROOT, 8000000); + clks[LPRCCLK] = clk_register_fixed_rate(&pdev->dev, "lprc_clk", NULL, + CLK_IS_ROOT, 32000); + clks[UPLLCLK] = clk_register_fixed_rate(&pdev->dev, "usbphy_clk", NULL, + CLK_IS_ROOT, 24000000); + /* fixed rate (optional) clock */ + if (of_find_property(np, "microchip,pic32mzda-sosc", NULL)) { + pr_info("pic32-clk: dt requests SOSC.\n"); + clks[SOSCCLK] = pic32_sosc_clk_register(&sosc_clk, core); + } + /* divider clock */ + clks[FRCDIVCLK] = clk_register_divider(&pdev->dev, "frcdiv_clk", + "frc_clk", 0, + core->iobase, + OSC_FRCDIV_SHIFT, + OSC_FRCDIV_MASK, + CLK_DIVIDER_POWER_OF_TWO, + &core->reg_lock); + /* PLL ICLK mux */ + pll_mux_clk = clk_register_mux(&pdev->dev, "spll_mux_clk", + pll_mux_parents, 2, 0, + core->iobase + 0x020, + PLL_ICLK_SHIFT, 1, 0, &core->reg_lock); + if (IS_ERR(pll_mux_clk)) + pr_err("spll_mux_clk: clk register failed\n"); + + /* PLL */ + clks[PLLCLK] = pic32_spll_clk_register(&sys_pll, core); + /* SYSTEM clock */ + clks[SCLK] = pic32_sys_clk_register(&sys_mux_clk, core); + /* Peripheral bus clocks */ + for (nr_clks = PB1CLK, i = 0; nr_clks <= PB7CLK; i++, nr_clks++) + clks[nr_clks] = pic32_periph_clk_register(&periph_clocks[i], + core); + /* Reference oscillator clock */ + for (nr_clks = REF1CLK, i = 0; nr_clks <= REF5CLK; i++, nr_clks++) + clks[nr_clks] = pic32_refo_clk_register(&ref_clks[i], core); + + /* register clkdev */ + for (i = 0; i < MAXCLKS; i++) { + if (IS_ERR(clks[i])) + continue; + clk_register_clkdev(clks[i], NULL, __clk_get_name(clks[i])); + } + + /* register clock provider */ + cd->onecell_data.clks = clks; + cd->onecell_data.clk_num = MAXCLKS; + ret = of_clk_add_provider(np, of_clk_src_onecell_get, + &cd->onecell_data); + if (ret) + return ret; + + /* force enable critical clocks */ + for (i = 0; i < ARRAY_SIZE(pic32mzda_critical_clks); i++) { + clk = clks[pic32mzda_critical_clks[i]]; + if (clk_prepare_enable(clk)) + dev_err(&pdev->dev, "clk_prepare_enable(%s) failed\n", + __clk_get_name(clk)); + } + + /* register NMI for failsafe clock monitor */ + cd->failsafe_notifier.notifier_call = pic32_fscm_nmi; + return register_nmi_notifier(&cd->failsafe_notifier); +} + +static const struct of_device_id pic32mzda_clk_match_table[] = { + { .compatible = "microchip,pic32mzda-clk", }, + { } +}; +MODULE_DEVICE_TABLE(of, pic32mzda_clk_match_table); + +static struct platform_driver pic32mzda_clk_driver = { + .probe = pic32mzda_clk_probe, + .driver = { + .name = "clk-pic32mzda", + .of_match_table = pic32mzda_clk_match_table, + }, +}; + +static int __init microchip_pic32mzda_clk_init(void) +{ + return platform_driver_register(&pic32mzda_clk_driver); +} +core_initcall(microchip_pic32mzda_clk_init); + +MODULE_DESCRIPTION("Microchip PIC32MZDA Clock Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:clk-pic32mzda"); |