[RFC PATCH 2/6] clk: sifive: Use reset-simple in prci driver for PCIe driver

From: Greentime Hu <greentime.hu@sifive.com>
To: greentime.hu@sifive.com, paul.walmsley@sifive.com,
	hes@sifive.com, erik.danie@sifive.com, zong.li@sifive.com,
	bhelgaas@google.com, robh+dt@kernel.org, palmer@dabbelt.com,
	aou@eecs.berkeley.edu, mturquette@baylibre.com, sboyd@kernel.org,
	lorenzo.pieralisi@arm.com, p.zabel@pengutronix.de,
	alex.dewar90@gmail.com, khilman@baylibre.com,
	hayashi.kunihiko@socionext.com, vidyas@nvidia.com,
	jh80.chung@samsung.com, linux-pci@vger.kernel.org,
	devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
Subject: [RFC PATCH 2/6] clk: sifive: Use reset-simple in prci driver for PCIe driver
Date: Tue,  2 Mar 2021 18:59:13 +0800	[thread overview]
Message-ID: <e2bd7db9db3c196b9b0399f0655a56939a0f3d62.1614681831.git.greentime.hu@sifive.com> (raw)
In-Reply-To: <cover.1614681831.git.greentime.hu@sifive.com>

We use reset-simple in this patch so that pcie driver can use
devm_reset_control_get() to get this reset data structure and use
reset_control_deassert() to deassert pcie_power_up_rst_n.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
---
 drivers/clk/sifive/Kconfig       |  2 ++
 drivers/clk/sifive/sifive-prci.c | 14 ++++++++++++++
 drivers/clk/sifive/sifive-prci.h |  4 ++++
 drivers/reset/Kconfig            |  3 ++-
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sifive/Kconfig b/drivers/clk/sifive/Kconfig
index 1c14eb20c066..9132c3c4aa86 100644
--- a/drivers/clk/sifive/Kconfig
+++ b/drivers/clk/sifive/Kconfig
@@ -10,6 +10,8 @@ if CLK_SIFIVE
 
 config CLK_SIFIVE_PRCI
 	bool "PRCI driver for SiFive SoCs"
+	select RESET_CONTROLLER
+	select RESET_SIMPLE
 	select CLK_ANALOGBITS_WRPLL_CLN28HPC
 	help
 	  Supports the Power Reset Clock interface (PRCI) IP block found in
diff --git a/drivers/clk/sifive/sifive-prci.c b/drivers/clk/sifive/sifive-prci.c
index baf7313dac92..925affc6de55 100644
--- a/drivers/clk/sifive/sifive-prci.c
+++ b/drivers/clk/sifive/sifive-prci.c
@@ -583,7 +583,21 @@ static int sifive_prci_probe(struct platform_device *pdev)
 	if (IS_ERR(pd->va))
 		return PTR_ERR(pd->va);
 
+	pd->reset.rcdev.owner = THIS_MODULE;
+	pd->reset.rcdev.nr_resets = PRCI_RST_NR;
+	pd->reset.rcdev.ops = &reset_simple_ops;
+	pd->reset.rcdev.of_node = pdev->dev.of_node;
+	pd->reset.active_low = true;
+	pd->reset.membase = pd->va + PRCI_DEVICESRESETREG_OFFSET;
+	spin_lock_init(&pd->reset.lock);
+
+	r = devm_reset_controller_register(&pdev->dev, &pd->reset.rcdev);
+	if (r) {
+		dev_err(dev, "could not register reset controller: %d\n", r);
+		return r;
+	}
 	r = __prci_register_clocks(dev, pd, desc);
+
 	if (r) {
 		dev_err(dev, "could not register clocks: %d\n", r);
 		return r;
diff --git a/drivers/clk/sifive/sifive-prci.h b/drivers/clk/sifive/sifive-prci.h
index 022c67cf053c..91658a88af4e 100644
--- a/drivers/clk/sifive/sifive-prci.h
+++ b/drivers/clk/sifive/sifive-prci.h
@@ -11,6 +11,7 @@
 
 #include <linux/clk/analogbits-wrpll-cln28hpc.h>
 #include <linux/clk-provider.h>
+#include <linux/reset/reset-simple.h>
 #include <linux/platform_device.h>
 
 /*
@@ -121,6 +122,8 @@
 #define PRCI_DEVICESRESETREG_CHIPLINK_RST_N_MASK			\
 		(0x1 << PRCI_DEVICESRESETREG_CHIPLINK_RST_N_SHIFT)
 
+#define PRCI_RST_NR						7
+
 /* CLKMUXSTATUSREG */
 #define PRCI_CLKMUXSTATUSREG_OFFSET				0x2c
 #define PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_SHIFT		1
@@ -221,6 +224,7 @@
  */
 struct __prci_data {
 	void __iomem *va;
+	struct reset_simple_data reset;
 	struct clk_hw_onecell_data hw_clks;
 };
 
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 71ab75a46491..f094df93d911 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -173,7 +173,7 @@ config RESET_SCMI
 
 config RESET_SIMPLE
 	bool "Simple Reset Controller Driver" if COMPILE_TEST
-	default ARCH_AGILEX || ARCH_ASPEED || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARC
+	default ARCH_AGILEX || ARCH_ASPEED || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARC || RISCV
 	help
 	  This enables a simple reset controller driver for reset lines that
 	  that can be asserted and deasserted by toggling bits in a contiguous,
@@ -187,6 +187,7 @@ config RESET_SIMPLE
 	   - RCC reset controller in STM32 MCUs
 	   - Allwinner SoCs
 	   - ZTE's zx2967 family
+	   - SiFive FU740 SoCs
 
 config RESET_STM32MP157
 	bool "STM32MP157 Reset Driver" if COMPILE_TEST
-- 
2.30.0

