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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-04 11:35:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-04 11:35:03 -0700
commit8bd8fd0a29bfd5ad8e1976edd8c4c40cdb39aa4f (patch)
tree1d7b2e30083194cc4223d9b150583fc2924bd032 /drivers/clocksource/clksrc_st_lpc.c
parent352712274507645b6f82b8763977ad87321919a3 (diff)
parent5a688c455066c21c133bc8ffa7b11f8c66b7fe0b (diff)
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Merge tag 'mfd-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
Pull MFD updates from Lee Jones: "New Device Support: - New Clocksource driver from ST - New MFD/ACPI/DMA drivers for Intel's Sunrisepoint PCH based platforms - Add support for Arizona WM8998 and WM1814 - Add support for Dialog Semi DA9062 and DA9063 - Add support for Kontron COMe-bBL6 and COMe-cBW6 - Add support for X-Powers AXP152 - Add support for Atmel, many - Add support for STMPE, many - Add support for USB in X-Powers AXP22X Core Frameworks: - New Base API to traverse devices and their children in reverse order Bug Fixes: - Fix race between runtime-suspend and IRQs - Obtain platform data form more reliable source Fix-ups: - Constifying things - Variable signage changes - Kconfig depends|selects changes - Make use of BIT() macro - Do not supply .owner attribute in *_driver structures - MAINTAINERS entries - Stop using set_irq_flags() - Start using irq_set_chained_handler_and_data() - Export DT device ID structures" * tag 'mfd-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (69 commits) mfd: jz4740-adc: Init mask cache in generic IRQ chip mfd: cros_ec: spi: Add OF match table mfd: stmpe: Add OF match table mfd: max77686: Split out regulator part from the DT binding mfd: Add DT binding for Maxim MAX77802 IC mfd: max77686: Use a generic name for the PMIC node in the example mfd: max77686: Don't suggest in binding to use a deprecated property mfd: Add MFD_CROS_EC dependencies mfd: cros_ec: Remove CROS_EC_PROTO dependency for SPI and I2C drivers mfd: axp20x: Add a cell for the usb power_supply part of the axp20x PMICs mfd: axp20x: Add missing registers, and mark more registers volatile mfd: arizona: Fixup some formatting/white space errors mfd: wm8994: Fix NULL pointer exception on missing pdata of: Add vendor prefix for Nuvoton mfd: mt6397: Implement wake handler and suspend/resume to handle wake up event mfd: atmel-hlcdc: Add support for new SoCs mfd: Export OF module alias information in missing drivers mfd: stw481x: Export I2C module alias information mfd: da9062: Support for the DA9063 OnKey in the DA9062 core mfd: max899x: Avoid redundant irq_data lookup ...
Diffstat (limited to 'drivers/clocksource/clksrc_st_lpc.c')
-rw-r--r--drivers/clocksource/clksrc_st_lpc.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/clocksource/clksrc_st_lpc.c b/drivers/clocksource/clksrc_st_lpc.c
new file mode 100644
index 000000000000..65ec4674416d
--- /dev/null
+++ b/drivers/clocksource/clksrc_st_lpc.c
@@ -0,0 +1,131 @@
+/*
+ * Clocksource using the Low Power Timer found in the Low Power Controller (LPC)
+ *
+ * Copyright (C) 2015 STMicroelectronics – All Rights Reserved
+ *
+ * Author(s): Francesco Virlinzi <francesco.virlinzi@st.com>
+ * Ajit Pal Singh <ajitpal.singh@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/mfd/st-lpc.h>
+
+/* Low Power Timer */
+#define LPC_LPT_LSB_OFF 0x400
+#define LPC_LPT_MSB_OFF 0x404
+#define LPC_LPT_START_OFF 0x408
+
+static struct st_clksrc_ddata {
+ struct clk *clk;
+ void __iomem *base;
+} ddata;
+
+static void __init st_clksrc_reset(void)
+{
+ writel_relaxed(0, ddata.base + LPC_LPT_START_OFF);
+ writel_relaxed(0, ddata.base + LPC_LPT_MSB_OFF);
+ writel_relaxed(0, ddata.base + LPC_LPT_LSB_OFF);
+ writel_relaxed(1, ddata.base + LPC_LPT_START_OFF);
+}
+
+static u64 notrace st_clksrc_sched_clock_read(void)
+{
+ return (u64)readl_relaxed(ddata.base + LPC_LPT_LSB_OFF);
+}
+
+static int __init st_clksrc_init(void)
+{
+ unsigned long rate;
+ int ret;
+
+ st_clksrc_reset();
+
+ rate = clk_get_rate(ddata.clk);
+
+ sched_clock_register(st_clksrc_sched_clock_read, 32, rate);
+
+ ret = clocksource_mmio_init(ddata.base + LPC_LPT_LSB_OFF,
+ "clksrc-st-lpc", rate, 300, 32,
+ clocksource_mmio_readl_up);
+ if (ret) {
+ pr_err("clksrc-st-lpc: Failed to register clocksource\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __init st_clksrc_setup_clk(struct device_node *np)
+{
+ struct clk *clk;
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("clksrc-st-lpc: Failed to get LPC clock\n");
+ return PTR_ERR(clk);
+ }
+
+ if (clk_prepare_enable(clk)) {
+ pr_err("clksrc-st-lpc: Failed to enable LPC clock\n");
+ return -EINVAL;
+ }
+
+ if (!clk_get_rate(clk)) {
+ pr_err("clksrc-st-lpc: Failed to get LPC clock rate\n");
+ clk_disable_unprepare(clk);
+ return -EINVAL;
+ }
+
+ ddata.clk = clk;
+
+ return 0;
+}
+
+static void __init st_clksrc_of_register(struct device_node *np)
+{
+ int ret;
+ uint32_t mode;
+
+ ret = of_property_read_u32(np, "st,lpc-mode", &mode);
+ if (ret) {
+ pr_err("clksrc-st-lpc: An LPC mode must be provided\n");
+ return;
+ }
+
+ /* LPC can either run as a Clocksource or in RTC or WDT mode */
+ if (mode != ST_LPC_MODE_CLKSRC)
+ return;
+
+ ddata.base = of_iomap(np, 0);
+ if (!ddata.base) {
+ pr_err("clksrc-st-lpc: Unable to map iomem\n");
+ return;
+ }
+
+ if (st_clksrc_setup_clk(np)) {
+ iounmap(ddata.base);
+ return;
+ }
+
+ if (st_clksrc_init()) {
+ clk_disable_unprepare(ddata.clk);
+ clk_put(ddata.clk);
+ iounmap(ddata.base);
+ return;
+ }
+
+ pr_info("clksrc-st-lpc: clocksource initialised - running @ %luHz\n",
+ clk_get_rate(ddata.clk));
+}
+CLOCKSOURCE_OF_DECLARE(ddata, "st,stih407-lpc", st_clksrc_of_register);
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