clk: sifive: Use reset-simple in prci driver for PCIe driver

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.

Link: https://lore.kernel.org/r/20210504105940.100004-3-greentime.hu@sifive.com
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Stephen Boyd <sboyd@kernel.org>

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

drivers/clk/sifive/sifive-prci.c

@@ -588,6 +588,19 @@ 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);

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;
 };
 

drivers/reset/Kconfig

@@ -197,6 +197,7 @@ 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