[PATCH 9/9] ARM: vf610: initial suspend/resume support

[Stefan Agner <stefan@agner.ch>]

This patch adds initial suspend/resume support for Vybrid SoC.
The standby sleep state puts the module in LP-RUN mode which
allows to the SoC to be woken by a regular interrupt. The mem
sleep state (Suspend-to-RAM) uses the STOP mode which puts the
memory in self-refresh mode but keeps the memory clock enabled.
To wake the SoC a power management wakeup IRQ need to be enabled
using irq_set_irq_wake (e.g. through a GPIO).

Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 arch/arm/mach-imx/Makefile     |   1 +
 arch/arm/mach-imx/clk-vf610.c  |   3 +
 arch/arm/mach-imx/common.h     |  10 +
 arch/arm/mach-imx/mach-vf610.c |   1 +
 arch/arm/mach-imx/pm-vf610.c   | 428 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 443 insertions(+)
 create mode 100644 arch/arm/mach-imx/pm-vf610.c

diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 6e4fcd8..0f558aa 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -103,6 +103,7 @@ AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o
 endif
 obj-$(CONFIG_SOC_IMX6) += pm-imx6.o
+obj-$(CONFIG_SOC_VF610) += pm-vf610.o
 
 obj-$(CONFIG_SOC_IMX50) += mach-imx50.o
 obj-$(CONFIG_SOC_IMX51) += mach-imx51.o
diff --git a/arch/arm/mach-imx/clk-vf610.c b/arch/arm/mach-imx/clk-vf610.c
index 1034e78..fbaa708 100644
--- a/arch/arm/mach-imx/clk-vf610.c
+++ b/arch/arm/mach-imx/clk-vf610.c
@@ -13,6 +13,7 @@
 #include <dt-bindings/clock/vf610-clock.h>
 
 #include "clk.h"
+#include "common.h"
 
 #define CCM_CCR			(ccm_base + 0x00)
 #define CCM_CSR			(ccm_base + 0x04)
@@ -131,6 +132,8 @@ static void __init vf610_clocks_init(struct device_node *ccm_node)
 	ccm_base = of_iomap(np, 0);
 	BUG_ON(!ccm_base);
 
+	vf610_pm_set_ccm_base(ccm_base);
+
 	clk[VF610_CLK_SLOW_CLK_SEL] = imx_clk_mux("slow_clk_sel", CCM_CCSR, 4, 1, slow_sels, ARRAY_SIZE(slow_sels));
 	clk[VF610_CLK_FASK_CLK_SEL] = imx_clk_mux("fast_clk_sel", CCM_CCSR, 5, 1, fast_sels, ARRAY_SIZE(fast_sels));
 
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index ca7a0d9..6dd360f 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h
@@ -80,6 +80,13 @@ enum mxc_cpu_pwr_mode {
 	STOP_POWER_OFF,		/* STOP + SRPG */
 };
 
+enum vf610_cpu_pwr_mode {
+	VF610_RUN,
+	VF610_LP_RUN,
+	VF610_STOP,
+	VF610_LP_STOP,
+};
+
 enum mx3_cpu_pwr_mode {
 	MX3_RUN,
 	MX3_WAIT,
@@ -125,6 +132,7 @@ int imx_cpu_kill(unsigned int cpu);
 #ifdef CONFIG_SUSPEND
 void v7_cpu_resume(void);
 void imx6_suspend(void __iomem *ocram_vbase);
+void vf610_suspend(void);
 #else
 static inline void v7_cpu_resume(void) {}
 static inline void imx6_suspend(void __iomem *ocram_vbase) {}
@@ -135,6 +143,8 @@ void imx6dl_pm_init(void);
 void imx6sl_pm_init(void);
 void imx6sx_pm_init(void);
 void imx6q_pm_set_ccm_base(void __iomem *base);
+void vf610_pm_init(void);
+void vf610_pm_set_ccm_base(void __iomem *base);
 
 #ifdef CONFIG_PM
 void imx51_pm_init(void);
diff --git a/arch/arm/mach-imx/mach-vf610.c b/arch/arm/mach-imx/mach-vf610.c
index eef3496..79f0461 100644
--- a/arch/arm/mach-imx/mach-vf610.c
+++ b/arch/arm/mach-imx/mach-vf610.c
@@ -25,6 +25,7 @@ static void __init vf610_init_machine(void)
 {
 	mxc_arch_reset_init_dt();
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	vf610_pm_init();
 }
 
 static const char * const vf610_dt_compat[] __initconst = {
diff --git a/arch/arm/mach-imx/pm-vf610.c b/arch/arm/mach-imx/pm-vf610.c
new file mode 100644
index 0000000..87dbbac
--- /dev/null
+++ b/arch/arm/mach-imx/pm-vf610.c
@@ -0,0 +1,428 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2014 Toradex AG
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/genalloc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/suspend.h>
+#include <linux/clk.h>
+#include <asm/cacheflush.h>
+#include <asm/fncpy.h>
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/tlb.h>
+
+#include "common.h"
+
+#define CCR				0x0
+#define BM_CCR_FIRC_EN			(0x1 << 16)
+#define BM_CCR_FXOSC_EN			(0x1 << 12)
+
+#define CCSR				0x8
+#define BM_CCSR_DDRC_CLK_SEL		(0x1 << 6)
+#define BM_CCSR_FAST_CLK_SEL		(0x1 << 5)
+#define BM_CCSR_SLOW_CLK_SEL		(0x1 << 4)
+#define BM_CCSR_SYS_CLK_SEL_MASK	(0x7 << 0)
+
+#define CLPCR				0x2c
+#define BM_CLPCR_ARM_CLK_DIS_ON_LPM	(0x1 << 5)
+#define BM_CLPCR_SBYOS			(0x1 << 6)
+#define BM_CLPCR_DIS_REF_OSC		(0x1 << 7)
+#define BM_CLPCR_ANADIG_STOP_MODE	(0x1 << 8)
+#define BM_CLPCR_FXOSC_BYPSEN		(0x1 << 10)
+#define BM_CLPCR_FXOSC_PWRDWN		(0x1 << 11)
+#define BM_CLPCR_MASK_CORE0_WFI		(0x1 << 22)
+#define BM_CLPCR_MASK_CORE1_WFI		(0x1 << 23)
+#define BM_CLPCR_MASK_SCU_IDLE		(0x1 << 24)
+#define BM_CLPCR_MASK_L2CC_IDLE		(0x1 << 25)
+
+#define CGPR				0x64
+#define BM_CGPR_INT_MEM_CLK_LPM		(0x1 << 17)
+
+#define GPC_PGCR			0x0
+#define BM_PGCR_DS_STOP			(0x1 << 7)
+#define BM_PGCR_DS_LPSTOP		(0x1 << 6)
+#define BM_PGCR_WB_STOP			(0x1 << 4)
+#define BM_PGCR_HP_OFF			(0x1 << 3)
+
+#define GPC_LPMR			0x40
+#define BM_LPMR_RUN			0x0
+#define BM_LPMR_STOP			0x2
+
+#define ANATOP_PLL1_CTRL		0x270
+#define ANATOP_PLL2_CTRL		0x30
+#define ANATOP_PLL3_CTRL		0x10
+#define ANATOP_PLL4_CTRL		0x70
+#define ANATOP_PLL5_CTRL		0xe0
+#define ANATOP_PLL6_CTRL		0xa0
+#define ANATOP_PLL7_CTRL		0x10
+#define BM_PLL_ENABLE		(0x1 << 13)
+#define BM_PLL_LOCK		(0x1 << 31)
+
+#define VF610_SUSPEND_OCRAM_SIZE	0x4000
+
+#define VF_UART0_BASE_ADDR	0x40027000
+#define VF_UART1_BASE_ADDR	0x40028000
+#define VF_UART2_BASE_ADDR	0x40029000
+#define VF_UART3_BASE_ADDR	0x4002a000
+#define VF_UART_BASE_ADDR(n)	VF_UART##n##_BASE_ADDR
+#define VF_UART_BASE(n)		VF_UART_BASE_ADDR(n)
+#define VF_UART_PHYSICAL_BASE	VF_UART_BASE(CONFIG_DEBUG_VF_UART_PORT)
+
+static void __iomem *ccm_base;
+static void __iomem *suspend_ocram_base;
+
+/*
+ * suspend ocram space layout:
+ * ======================== high address ======================
+ *                              .
+ *                              .
+ *                              .
+ *                              ^
+ *                              ^
+ *                              ^
+ *                      vf610_suspend code
+ *              PM_INFO structure(vf610_cpu_pm_info)
+ * ======================== low address =======================
+ */
+
+struct vf610_pm_base {
+	phys_addr_t pbase;
+	void __iomem *vbase;
+};
+
+struct vf610_pm_socdata {
+	const char *src_compat;
+	const char *gpc_compat;
+	const char *anatop_compat;
+};
+
+static const struct vf610_pm_socdata vf610_pm_data __initconst = {
+	.src_compat = "fsl,vf610-src",
+	.gpc_compat = "fsl,vf610-gpc",
+	.anatop_compat = "fsl,vf610-anatop",
+};
+
+/*
+ * This structure is for passing necessary data for low level ocram
+ * suspend code(arch/arm/mach-imx/suspend-vf610.S), if this struct
+ * definition is changed, the offset definition in
+ * arch/arm/mach-imx/suspend-vf610.S must be also changed accordingly,
+ * otherwise, the suspend to ocram function will be broken!
+ */
+struct vf610_cpu_pm_info {
+	phys_addr_t pbase; /* The physical address of pm_info. */
+	phys_addr_t resume_addr; /* The physical resume address for asm code */
+	u32 cpu_type; /* Currently not used, leave it for alignment */
+	u32 pm_info_size; /* Size of pm_info. */
+	struct vf610_pm_base anatop_base;
+	struct vf610_pm_base src_base;
+	struct vf610_pm_base ccm_base;
+	struct vf610_pm_base gpc_base;
+	struct vf610_pm_base l2_base;
+} __aligned(8);
+
+#ifdef DEBUG
+static void uart_reinit(unsigned long int rate, unsigned long int baud)
+{
+	void __iomem *membase = ioremap(VF_UART_PHYSICAL_BASE, 0x1000);
+	u8 tmp;
+	u16 sbr, brfa;
+
+	/* UART_C2 */
+	__raw_writeb(0, membase + 0x3);
+
+	sbr = (u16) (rate / (baud * 16));
+	brfa = (rate / baud) - (sbr * 16);
+
+	tmp = ((sbr & 0x1f00) >> 8);
+	__raw_writeb(tmp, membase + 0x0);
+	tmp = sbr & 0x00ff;
+	__raw_writeb(tmp, membase + 0x1);
+
+	/* UART_C4 */
+	__raw_writeb(brfa & 0xf, membase + 0xa);
+
+	/* UART_C2 */
+	__raw_writeb(0xac, membase + 0x3);
+
+	iounmap(membase);
+}
+#else
+static void uart_reinit(unsigned long int rate, unsigned long int baud) {}
+#endif
+
+static void vf610_enable_pll(void __iomem *pll_base)
+{
+	writel_relaxed(readl_relaxed(pll_base) | BM_PLL_ENABLE, pll_base);
+}
+
+static void vf610_disable_pll(void __iomem *pll_base)
+{
+	writel_relaxed(readl_relaxed(pll_base) & ~BM_PLL_ENABLE, pll_base);
+}
+
+int vf610_set_lpm(enum vf610_cpu_pwr_mode mode)
+{
+	u32 ccr = readl_relaxed(ccm_base + CCR);
+	u32 ccsr = readl_relaxed(ccm_base + CCSR);
+	u32 cclpcr = readl_relaxed(ccm_base + CLPCR);
+	struct vf610_cpu_pm_info *pm_info = suspend_ocram_base;
+	void __iomem *gpc_base = pm_info->gpc_base.vbase;
+	u32 gpc_pgcr = readl_relaxed(gpc_base + GPC_PGCR);
+	void __iomem *anatop = pm_info->anatop_base.vbase;
+
+	switch (mode) {
+	case VF610_STOP:
+		cclpcr &= ~BM_CLPCR_ANADIG_STOP_MODE;
+		cclpcr |= BM_CLPCR_ARM_CLK_DIS_ON_LPM;
+		cclpcr &= ~BM_CLPCR_SBYOS;
+		writel_relaxed(cclpcr, ccm_base + CLPCR);
+
+		gpc_pgcr |= BM_PGCR_DS_STOP;
+		gpc_pgcr |= BM_PGCR_HP_OFF;
+		writel_relaxed(gpc_pgcr, gpc_base + GPC_PGCR);
+
+		writel_relaxed(BM_LPMR_STOP, gpc_base + GPC_LPMR);
+		/* fall-through */
+	case VF610_LP_RUN:
+		ccr |= BM_CCR_FIRC_EN;
+		writel_relaxed(ccr, ccm_base + CCR);
+
+		/* Switch internal OSC's */
+		ccsr &= ~BM_CCSR_FAST_CLK_SEL;
+		ccsr &= ~BM_CCSR_SLOW_CLK_SEL;
+		writel_relaxed(ccsr, ccm_base + CCSR);
+
+		ccsr &= ~BM_CCSR_SYS_CLK_SEL_MASK;
+		writel_relaxed(ccsr, ccm_base + CCSR);
+		uart_reinit(4000000UL, 115200);
+
+		vf610_disable_pll(anatop + ANATOP_PLL1_CTRL);
+		vf610_disable_pll(anatop + ANATOP_PLL3_CTRL);
+		vf610_disable_pll(anatop + ANATOP_PLL5_CTRL);
+		vf610_disable_pll(anatop + ANATOP_PLL7_CTRL);
+		break;
+	case VF610_RUN:
+		vf610_enable_pll(anatop + ANATOP_PLL1_CTRL);
+		vf610_enable_pll(anatop + ANATOP_PLL3_CTRL);
+		vf610_enable_pll(anatop + ANATOP_PLL5_CTRL);
+		vf610_enable_pll(anatop + ANATOP_PLL7_CTRL);
+
+		ccsr &= ~BM_CCSR_SYS_CLK_SEL_MASK;
+		ccsr |= 0x4;
+		writel_relaxed(ccsr, ccm_base + CCSR);
+		uart_reinit(83368421UL, 115200);
+
+		writel_relaxed(BM_LPMR_RUN, gpc_base + GPC_LPMR);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int vf610_pm_enter(suspend_state_t state)
+{
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+		vf610_set_lpm(VF610_LP_RUN);
+		imx_gpc_pre_suspend(false);
+
+		/* zzZZZzzz */
+		cpu_do_idle();
+
+		imx_gpc_post_resume();
+		vf610_set_lpm(VF610_RUN);
+		break;
+	case PM_SUSPEND_MEM:
+		vf610_set_lpm(VF610_STOP);
+		imx_gpc_pre_suspend(false);
+
+		cpu_do_idle();
+
+		imx_gpc_post_resume();
+		vf610_set_lpm(VF610_RUN);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int vf610_pm_valid(suspend_state_t state)
+{
+	return (state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM);
+}
+
+static const struct platform_suspend_ops vf610_pm_ops = {
+	.enter = vf610_pm_enter,
+	.valid = vf610_pm_valid,
+};
+
+void __init vf610_pm_set_ccm_base(void __iomem *base)
+{
+	ccm_base = base;
+}
+
+static int __init imx_pm_get_base(struct vf610_pm_base *base,
+				const char *compat)
+{
+	struct device_node *node;
+	struct resource res;
+	int ret = 0;
+
+	node = of_find_compatible_node(NULL, NULL, compat);
+	if (!node) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = of_address_to_resource(node, 0, &res);
+	if (ret)
+		goto put_node;
+
+	base->pbase = res.start;
+	base->vbase = ioremap(res.start, resource_size(&res));
+
+	if (!base->vbase)
+		ret = -ENOMEM;
+
+put_node:
+	of_node_put(node);
+out:
+	return ret;
+}
+
+static int __init vf610_suspend_init(const struct vf610_pm_socdata *socdata)
+{
+	phys_addr_t ocram_pbase;
+	struct device_node *node;
+	struct platform_device *pdev;
+	struct vf610_cpu_pm_info *pm_info;
+	struct gen_pool *ocram_pool;
+	unsigned long ocram_base;
+	int ret = 0;
+
+	suspend_set_ops(&vf610_pm_ops);
+
+	if (!socdata) {
+		pr_warn("%s: invalid argument!\n", __func__);
+		return -EINVAL;
+	}
+
+	node = of_find_compatible_node(NULL, NULL, "mmio-sram");
+	if (!node) {
+		pr_warn("%s: failed to find ocram node!\n", __func__);
+		return -ENODEV;
+	}
+
+	pdev = of_find_device_by_node(node);
+	if (!pdev) {
+		pr_warn("%s: failed to find ocram device!\n", __func__);
+		ret = -ENODEV;
+		goto put_node;
+	}
+
+	ocram_pool = dev_get_gen_pool(&pdev->dev);
+	if (!ocram_pool) {
+		pr_warn("%s: ocram pool unavailable!\n", __func__);
+		ret = -ENODEV;
+		goto put_node;
+	}
+
+	ocram_base = gen_pool_alloc(ocram_pool, VF610_SUSPEND_OCRAM_SIZE);
+	if (!ocram_base) {
+		pr_warn("%s: unable to alloc ocram!\n", __func__);
+		ret = -ENOMEM;
+		goto put_node;
+	}
+
+	ocram_pbase = gen_pool_virt_to_phys(ocram_pool, ocram_base);
+
+	suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
+		VF610_SUSPEND_OCRAM_SIZE, false);
+
+	pm_info = suspend_ocram_base;
+	pm_info->pbase = ocram_pbase;
+	pm_info->pm_info_size = sizeof(*pm_info);
+
+	/*
+	 * ccm physical address is not used by asm code currently,
+	 * so get ccm virtual address directly, as we already have
+	 * it from ccm driver.
+	 */
+	pm_info->ccm_base.vbase = ccm_base;
+
+	ret = imx_pm_get_base(&pm_info->anatop_base, socdata->anatop_compat);
+	if (ret) {
+		pr_warn("%s: failed to get anatop base %d!\n", __func__, ret);
+		goto put_node;
+	}
+
+	ret = imx_pm_get_base(&pm_info->src_base, socdata->src_compat);
+	if (ret) {
+		pr_warn("%s: failed to get src base %d!\n", __func__, ret);
+		goto src_map_failed;
+	}
+
+	ret = imx_pm_get_base(&pm_info->gpc_base, socdata->gpc_compat);
+	if (ret) {
+		pr_warn("%s: failed to get gpc base %d!\n", __func__, ret);
+		goto gpc_map_failed;
+	}
+
+	ret = imx_pm_get_base(&pm_info->l2_base, "arm,pl310-cache");
+	if (ret) {
+		pr_warn("%s: failed to get pl310-cache base %d!\n",
+			__func__, ret);
+		goto pl310_cache_map_failed;
+	}
+
+	goto put_node;
+
+pl310_cache_map_failed:
+	iounmap(&pm_info->gpc_base.vbase);
+gpc_map_failed:
+	iounmap(&pm_info->src_base.vbase);
+src_map_failed:
+	iounmap(&pm_info->anatop_base.vbase);
+put_node:
+	of_node_put(node);
+
+	return ret;
+}
+
+void __init vf610_pm_init(void)
+{
+	int ret;
+
+	WARN_ON(!ccm_base);
+
+	if (IS_ENABLED(CONFIG_SUSPEND)) {
+		ret = vf610_suspend_init(&vf610_pm_data);
+		if (ret)
+			pr_warn("%s: No DDR LPM support with suspend %d!\n",
+				__func__, ret);
+	}
+}
+
-- 
2.1.0