| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) STMicroelectronics 2018 - All Rights Reserved |
| * Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics. |
| * Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics. |
| */ |
| |
| #include <linux/bitfield.h> |
| #include <linux/clk.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/mailbox_controller.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/pm_wakeirq.h> |
| |
| #define IPCC_XCR 0x000 |
| #define XCR_RXOIE BIT(0) |
| #define XCR_TXOIE BIT(16) |
| |
| #define IPCC_XMR 0x004 |
| #define IPCC_XSCR 0x008 |
| #define IPCC_XTOYSR 0x00c |
| |
| #define IPCC_PROC_OFFST 0x010 |
| |
| #define IPCC_HWCFGR 0x3f0 |
| #define IPCFGR_CHAN_MASK GENMASK(7, 0) |
| |
| #define IPCC_VER 0x3f4 |
| #define VER_MINREV_MASK GENMASK(3, 0) |
| #define VER_MAJREV_MASK GENMASK(7, 4) |
| |
| #define RX_BIT_MASK GENMASK(15, 0) |
| #define RX_BIT_CHAN(chan) BIT(chan) |
| #define TX_BIT_SHIFT 16 |
| #define TX_BIT_MASK GENMASK(31, 16) |
| #define TX_BIT_CHAN(chan) BIT(TX_BIT_SHIFT + (chan)) |
| |
| #define STM32_MAX_PROCS 2 |
| |
| enum { |
| IPCC_IRQ_RX, |
| IPCC_IRQ_TX, |
| IPCC_IRQ_NUM, |
| }; |
| |
| struct stm32_ipcc { |
| struct mbox_controller controller; |
| void __iomem *reg_base; |
| void __iomem *reg_proc; |
| struct clk *clk; |
| spinlock_t lock; /* protect access to IPCC registers */ |
| int irqs[IPCC_IRQ_NUM]; |
| u32 proc_id; |
| u32 n_chans; |
| u32 xcr; |
| u32 xmr; |
| }; |
| |
| static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg, |
| u32 mask) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(lock, flags); |
| writel_relaxed(readl_relaxed(reg) | mask, reg); |
| spin_unlock_irqrestore(lock, flags); |
| } |
| |
| static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg, |
| u32 mask) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(lock, flags); |
| writel_relaxed(readl_relaxed(reg) & ~mask, reg); |
| spin_unlock_irqrestore(lock, flags); |
| } |
| |
| static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data) |
| { |
| struct stm32_ipcc *ipcc = data; |
| struct device *dev = ipcc->controller.dev; |
| u32 status, mr, tosr, chan; |
| irqreturn_t ret = IRQ_NONE; |
| int proc_offset; |
| |
| /* read 'channel occupied' status from other proc */ |
| proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST; |
| tosr = readl_relaxed(ipcc->reg_proc + proc_offset + IPCC_XTOYSR); |
| mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR); |
| |
| /* search for unmasked 'channel occupied' */ |
| status = tosr & FIELD_GET(RX_BIT_MASK, ~mr); |
| |
| for (chan = 0; chan < ipcc->n_chans; chan++) { |
| if (!(status & (1 << chan))) |
| continue; |
| |
| dev_dbg(dev, "%s: chan:%d rx\n", __func__, chan); |
| |
| mbox_chan_received_data(&ipcc->controller.chans[chan], NULL); |
| |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR, |
| RX_BIT_CHAN(chan)); |
| |
| ret = IRQ_HANDLED; |
| } |
| |
| return ret; |
| } |
| |
| static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data) |
| { |
| struct stm32_ipcc *ipcc = data; |
| struct device *dev = ipcc->controller.dev; |
| u32 status, mr, tosr, chan; |
| irqreturn_t ret = IRQ_NONE; |
| |
| tosr = readl_relaxed(ipcc->reg_proc + IPCC_XTOYSR); |
| mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR); |
| |
| /* search for unmasked 'channel free' */ |
| status = ~tosr & FIELD_GET(TX_BIT_MASK, ~mr); |
| |
| for (chan = 0; chan < ipcc->n_chans ; chan++) { |
| if (!(status & (1 << chan))) |
| continue; |
| |
| dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan); |
| |
| /* mask 'tx channel free' interrupt */ |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR, |
| TX_BIT_CHAN(chan)); |
| |
| mbox_chan_txdone(&ipcc->controller.chans[chan], 0); |
| |
| ret = IRQ_HANDLED; |
| } |
| |
| return ret; |
| } |
| |
| static int stm32_ipcc_send_data(struct mbox_chan *link, void *data) |
| { |
| unsigned long chan = (unsigned long)link->con_priv; |
| struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc, |
| controller); |
| |
| dev_dbg(ipcc->controller.dev, "%s: chan:%lu\n", __func__, chan); |
| |
| /* set channel n occupied */ |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR, |
| TX_BIT_CHAN(chan)); |
| |
| /* unmask 'tx channel free' interrupt */ |
| stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR, |
| TX_BIT_CHAN(chan)); |
| |
| return 0; |
| } |
| |
| static int stm32_ipcc_startup(struct mbox_chan *link) |
| { |
| unsigned long chan = (unsigned long)link->con_priv; |
| struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc, |
| controller); |
| int ret; |
| |
| ret = clk_prepare_enable(ipcc->clk); |
| if (ret) { |
| dev_err(ipcc->controller.dev, "can not enable the clock\n"); |
| return ret; |
| } |
| |
| /* unmask 'rx channel occupied' interrupt */ |
| stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR, |
| RX_BIT_CHAN(chan)); |
| |
| return 0; |
| } |
| |
| static void stm32_ipcc_shutdown(struct mbox_chan *link) |
| { |
| unsigned long chan = (unsigned long)link->con_priv; |
| struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc, |
| controller); |
| |
| /* mask rx/tx interrupt */ |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR, |
| RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan)); |
| |
| clk_disable_unprepare(ipcc->clk); |
| } |
| |
| static const struct mbox_chan_ops stm32_ipcc_ops = { |
| .send_data = stm32_ipcc_send_data, |
| .startup = stm32_ipcc_startup, |
| .shutdown = stm32_ipcc_shutdown, |
| }; |
| |
| static int stm32_ipcc_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct device_node *np = dev->of_node; |
| struct stm32_ipcc *ipcc; |
| unsigned long i; |
| int ret; |
| u32 ip_ver; |
| static const char * const irq_name[] = {"rx", "tx"}; |
| irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq}; |
| |
| if (!np) { |
| dev_err(dev, "No DT found\n"); |
| return -ENODEV; |
| } |
| |
| ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL); |
| if (!ipcc) |
| return -ENOMEM; |
| |
| spin_lock_init(&ipcc->lock); |
| |
| /* proc_id */ |
| if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) { |
| dev_err(dev, "Missing st,proc-id\n"); |
| return -ENODEV; |
| } |
| |
| if (ipcc->proc_id >= STM32_MAX_PROCS) { |
| dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id); |
| return -EINVAL; |
| } |
| |
| /* regs */ |
| ipcc->reg_base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(ipcc->reg_base)) |
| return PTR_ERR(ipcc->reg_base); |
| |
| ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST; |
| |
| /* clock */ |
| ipcc->clk = devm_clk_get(dev, NULL); |
| if (IS_ERR(ipcc->clk)) |
| return PTR_ERR(ipcc->clk); |
| |
| ret = clk_prepare_enable(ipcc->clk); |
| if (ret) { |
| dev_err(dev, "can not enable the clock\n"); |
| return ret; |
| } |
| |
| /* irq */ |
| for (i = 0; i < IPCC_IRQ_NUM; i++) { |
| ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]); |
| if (ipcc->irqs[i] < 0) { |
| ret = ipcc->irqs[i]; |
| goto err_clk; |
| } |
| |
| ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL, |
| irq_thread[i], IRQF_ONESHOT, |
| dev_name(dev), ipcc); |
| if (ret) { |
| dev_err(dev, "failed to request irq %lu (%d)\n", i, ret); |
| goto err_clk; |
| } |
| } |
| |
| /* mask and enable rx/tx irq */ |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR, |
| RX_BIT_MASK | TX_BIT_MASK); |
| stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR, |
| XCR_RXOIE | XCR_TXOIE); |
| |
| /* wakeup */ |
| if (of_property_read_bool(np, "wakeup-source")) { |
| device_set_wakeup_capable(dev, true); |
| |
| ret = dev_pm_set_wake_irq(dev, ipcc->irqs[IPCC_IRQ_RX]); |
| if (ret) { |
| dev_err(dev, "Failed to set wake up irq\n"); |
| goto err_init_wkp; |
| } |
| } |
| |
| /* mailbox controller */ |
| ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR); |
| ipcc->n_chans &= IPCFGR_CHAN_MASK; |
| |
| ipcc->controller.dev = dev; |
| ipcc->controller.txdone_irq = true; |
| ipcc->controller.ops = &stm32_ipcc_ops; |
| ipcc->controller.num_chans = ipcc->n_chans; |
| ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans, |
| sizeof(*ipcc->controller.chans), |
| GFP_KERNEL); |
| if (!ipcc->controller.chans) { |
| ret = -ENOMEM; |
| goto err_irq_wkp; |
| } |
| |
| for (i = 0; i < ipcc->controller.num_chans; i++) |
| ipcc->controller.chans[i].con_priv = (void *)i; |
| |
| ret = devm_mbox_controller_register(dev, &ipcc->controller); |
| if (ret) |
| goto err_irq_wkp; |
| |
| platform_set_drvdata(pdev, ipcc); |
| |
| ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER); |
| |
| dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n", |
| FIELD_GET(VER_MAJREV_MASK, ip_ver), |
| FIELD_GET(VER_MINREV_MASK, ip_ver), |
| ipcc->controller.num_chans, ipcc->proc_id); |
| |
| clk_disable_unprepare(ipcc->clk); |
| return 0; |
| |
| err_irq_wkp: |
| if (of_property_read_bool(np, "wakeup-source")) |
| dev_pm_clear_wake_irq(dev); |
| err_init_wkp: |
| device_set_wakeup_capable(dev, false); |
| err_clk: |
| clk_disable_unprepare(ipcc->clk); |
| return ret; |
| } |
| |
| static int stm32_ipcc_remove(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| |
| if (of_property_read_bool(dev->of_node, "wakeup-source")) |
| dev_pm_clear_wake_irq(&pdev->dev); |
| |
| device_set_wakeup_capable(dev, false); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int stm32_ipcc_suspend(struct device *dev) |
| { |
| struct stm32_ipcc *ipcc = dev_get_drvdata(dev); |
| |
| ipcc->xmr = readl_relaxed(ipcc->reg_proc + IPCC_XMR); |
| ipcc->xcr = readl_relaxed(ipcc->reg_proc + IPCC_XCR); |
| |
| return 0; |
| } |
| |
| static int stm32_ipcc_resume(struct device *dev) |
| { |
| struct stm32_ipcc *ipcc = dev_get_drvdata(dev); |
| |
| writel_relaxed(ipcc->xmr, ipcc->reg_proc + IPCC_XMR); |
| writel_relaxed(ipcc->xcr, ipcc->reg_proc + IPCC_XCR); |
| |
| return 0; |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(stm32_ipcc_pm_ops, |
| stm32_ipcc_suspend, stm32_ipcc_resume); |
| |
| static const struct of_device_id stm32_ipcc_of_match[] = { |
| { .compatible = "st,stm32mp1-ipcc" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, stm32_ipcc_of_match); |
| |
| static struct platform_driver stm32_ipcc_driver = { |
| .driver = { |
| .name = "stm32-ipcc", |
| .pm = &stm32_ipcc_pm_ops, |
| .of_match_table = stm32_ipcc_of_match, |
| }, |
| .probe = stm32_ipcc_probe, |
| .remove = stm32_ipcc_remove, |
| }; |
| |
| module_platform_driver(stm32_ipcc_driver); |
| |
| MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>"); |
| MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>"); |
| MODULE_DESCRIPTION("STM32 IPCC driver"); |
| MODULE_LICENSE("GPL v2"); |