From f13a8268c1ea4a52aedbd2da60c050cff61cc022 Mon Sep 17 00:00:00 2001 From: David Collins Date: Thu, 20 Apr 2017 16:34:46 -0700 Subject: [PATCH] spmi: spmi-pmic-arb-debug: add clock management support Add support to enable and disable the clock used by the SPMI PMIC arbiter debug bus. This is needed to avoid unclocked accesses. Change-Id: If9eee1317a88c143452d8b46b89aff89d1e956b7 Signed-off-by: David Collins --- drivers/spmi/spmi-pmic-arb-debug.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/spmi/spmi-pmic-arb-debug.c b/drivers/spmi/spmi-pmic-arb-debug.c index ba3fe4010ce2..a5d77ea9f424 100644 --- a/drivers/spmi/spmi-pmic-arb-debug.c +++ b/drivers/spmi/spmi-pmic-arb-debug.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only /* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved. */ +#include #include #include #include @@ -59,6 +60,7 @@ enum pmic_arb_cmd_op_code { struct spmi_pmic_arb_debug { void __iomem *addr; raw_spinlock_t lock; + struct clk *clock; }; static inline void pmic_arb_debug_write(struct spmi_pmic_arb_debug *pa, @@ -171,6 +173,12 @@ static int pmic_arb_debug_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, else return -EINVAL; + rc = clk_prepare_enable(pa->clock); + if (rc) { + pr_err("%s: failed to enable core clock, rc=%d\n", + __func__, rc); + return rc; + } raw_spin_lock_irqsave(&pa->lock, flags); rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len); @@ -182,6 +190,7 @@ static int pmic_arb_debug_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, buf[i] = pmic_arb_debug_read(pa, PMIC_ARB_DEBUG_RDATA(i)); done: raw_spin_unlock_irqrestore(&pa->lock, flags); + clk_disable_unprepare(pa->clock); return rc; } @@ -211,6 +220,12 @@ static int pmic_arb_debug_write_cmd(struct spmi_controller *ctrl, u8 opc, else return -EINVAL; + rc = clk_prepare_enable(pa->clock); + if (rc) { + pr_err("%s: failed to enable core clock, rc=%d\n", + __func__, rc); + return rc; + } raw_spin_lock_irqsave(&pa->lock, flags); /* Write data to FIFO */ @@ -220,6 +235,7 @@ static int pmic_arb_debug_write_cmd(struct spmi_controller *ctrl, u8 opc, rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len); raw_spin_unlock_irqrestore(&pa->lock, flags); + clk_disable_unprepare(pa->clock); return rc; } @@ -283,6 +299,17 @@ static int spmi_pmic_arb_debug_probe(struct platform_device *pdev) goto err_put_ctrl; } + if (of_find_property(pdev->dev.of_node, "clock-names", NULL)) { + pa->clock = devm_clk_get(&pdev->dev, "core_clk"); + if (IS_ERR(pa->clock)) { + rc = PTR_ERR(pa->clock); + if (rc != -EPROBE_DEFER) + dev_err(&pdev->dev, "unable to request core clock, rc=%d\n", + rc); + goto err_put_ctrl; + } + } + platform_set_drvdata(pdev, ctrl); raw_spin_lock_init(&pa->lock);