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path: root/drivers/clk/microchip/clk-pic32mzda.c
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-rw-r--r--drivers/clk/microchip/clk-pic32mzda.c275
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");