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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 16:38:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 16:38:41 -0800
commit48c1c40ab40cb087b992e7b77518c3a2926743cc (patch)
tree8e5fcd8f0e45f6e05e08c2c8307417f17341768f /drivers/reset/core.c
parentMerge tag 'arm-soc-dt-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc (diff)
parentsoc: mediatek: mmsys: Specify HAS_IOMEM dependency for MTK_MMSYS (diff)
downloadlinux-dev-48c1c40ab40cb087b992e7b77518c3a2926743cc.tar.xz
linux-dev-48c1c40ab40cb087b992e7b77518c3a2926743cc.zip
Merge tag 'arm-soc-drivers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Arnd Bergmann: "There are a couple of subsystems maintained by other people that merge their drivers through the SoC tree, those changes include: - The SCMI firmware framework gains support for sensor notifications and for controlling voltage domains. - A large update for the Tegra memory controller driver, integrating it better with the interconnect framework - The memory controller subsystem gains support for Mediatek MT8192 - The reset controller framework gains support for sharing pulsed resets For Soc specific drivers in drivers/soc, the main changes are - The Allwinner/sunxi MBUS gets a rework for the way it handles dma_map_ops and offsets between physical and dma address spaces. - An errata fix plus some cleanups for Freescale Layerscape SoCs - A cleanup for renesas drivers regarding MMIO accesses. - New SoC specific drivers for Mediatek MT8192 and MT8183 power domains - New SoC specific drivers for Aspeed AST2600 LPC bus control and SoC identification. - Core Power Domain support for Qualcomm MSM8916, MSM8939, SDM660 and SDX55. - A rework of the TI AM33xx 'genpd' power domain support to use information from DT instead of platform data - Support for TI AM64x SoCs - Allow building some Amlogic drivers as modules instead of built-in Finally, there are numerous cleanups and smaller bug fixes for Mediatek, Tegra, Samsung, Qualcomm, TI OMAP, Amlogic, Rockchips, Renesas, and Xilinx SoCs" * tag 'arm-soc-drivers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (222 commits) soc: mediatek: mmsys: Specify HAS_IOMEM dependency for MTK_MMSYS firmware: xilinx: Properly align function parameter firmware: xilinx: Add a blank line after function declaration firmware: xilinx: Remove additional newline firmware: xilinx: Fix kernel-doc warnings firmware: xlnx-zynqmp: fix compilation warning soc: xilinx: vcu: add missing register NUM_CORE soc: xilinx: vcu: use vcu-settings syscon registers dt-bindings: soc: xlnx: extract xlnx, vcu-settings to separate binding soc: xilinx: vcu: drop useless success message clk: samsung: mark PM functions as __maybe_unused soc: samsung: exynos-chipid: initialize later - with arch_initcall soc: samsung: exynos-chipid: order list of SoCs by name memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe() memory: ti-emif-sram: only build for ARMv7 memory: tegra30: Support interconnect framework memory: tegra20: Support hardware versioning and clean up OPP table initialization dt-bindings: memory: tegra20-emc: Document opp-supported-hw property soc: rockchip: io-domain: Fix error return code in rockchip_iodomain_probe() reset-controller: ti: force the write operation when assert or deassert ...
Diffstat (limited to 'drivers/reset/core.c')
-rw-r--r--drivers/reset/core.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index a2df88e90011..34e89aa0fb5e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -208,6 +208,39 @@ static int reset_control_array_reset(struct reset_control_array *resets)
return 0;
}
+static int reset_control_array_rearm(struct reset_control_array *resets)
+{
+ struct reset_control *rstc;
+ int i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (!rstc)
+ continue;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+ return -EINVAL;
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+ }
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (rstc && rstc->shared)
+ WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+ }
+
+ return 0;
+}
+
static int reset_control_array_assert(struct reset_control_array *resets)
{
int ret, i;
@@ -326,6 +359,46 @@ int reset_control_reset(struct reset_control *rstc)
EXPORT_SYMBOL_GPL(reset_control_reset);
/**
+ * reset_control_rearm - allow shared reset line to be re-triggered"
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance, except if this call is used.
+ *
+ * Calls to this function must be balanced with calls to reset_control_reset,
+ * a warning is thrown in case triggered_count ever dips below 0.
+ *
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset or reset_control_rearm have been used.
+ *
+ * If rstc is NULL the function will just return 0.
+ */
+int reset_control_rearm(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_rearm(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
+ return -EINVAL;
+
+ WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_rearm);
+
+/**
* reset_control_assert - asserts the reset line
* @rstc: reset controller
*