diff options
author | Fabien Dessenne <fabien.dessenne@st.com> | 2018-05-31 10:27:25 +0200 |
---|---|---|
committer | Jassi Brar <jaswinder.singh@linaro.org> | 2018-06-06 22:21:59 +0530 |
commit | ffbded7dee975632f5ca56e565e68e84457f9213 (patch) | |
tree | 879cde90d922f119b89d497529af088b162ac37e /drivers/mailbox | |
parent | 8f51bb7caeb3731f3fff39109a45ed2c484dd30a (diff) | |
download | linux-ffbded7dee975632f5ca56e565e68e84457f9213.tar.gz linux-ffbded7dee975632f5ca56e565e68e84457f9213.tar.bz2 linux-ffbded7dee975632f5ca56e565e68e84457f9213.zip |
mailbox: add STMicroelectronics STM32 IPCC driver
The STMicroelectronics STM32 Inter-Processor Communication Controller
(IPCC) is used for communicating data between two processors.
It provides a non blocking signaling mechanism to post and retrieve
communication data in an atomic way.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Diffstat (limited to 'drivers/mailbox')
-rw-r--r-- | drivers/mailbox/Kconfig | 8 | ||||
-rw-r--r-- | drivers/mailbox/Makefile | 2 | ||||
-rw-r--r-- | drivers/mailbox/stm32-ipcc.c | 402 |
3 files changed, 412 insertions, 0 deletions
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index 725dce5ba62d..fb3f250e587b 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig @@ -177,4 +177,12 @@ config BCM_FLEXRM_MBOX Mailbox implementation of the Broadcom FlexRM ring manager, which provides access to various offload engines on Broadcom SoCs. Say Y here if you want to use the Broadcom FlexRM. + +config STM32_IPCC + tristate "STM32 IPCC Mailbox" + depends on MACH_STM32MP157 + help + Mailbox implementation for STMicroelectonics STM32 family chips + with hardware for Inter-Processor Communication Controller (IPCC) + between processors. Say Y here if you want to have this support. endif diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index cc23c3a43fcd..4d501bea7863 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile @@ -38,3 +38,5 @@ obj-$(CONFIG_BCM_FLEXRM_MBOX) += bcm-flexrm-mailbox.o obj-$(CONFIG_QCOM_APCS_IPC) += qcom-apcs-ipc-mailbox.o obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o + +obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c new file mode 100644 index 000000000000..533b0da5235d --- /dev/null +++ b/drivers/mailbox/stm32-ipcc.c @@ -0,0 +1,402 @@ +// 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/mailbox_controller.h> +#include <linux/module.h> +#include <linux/of_irq.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; + int irqs[IPCC_IRQ_NUM]; + int wkp; + u32 proc_id; + u32 n_chans; + u32 xcr; + u32 xmr; +}; + +static inline void stm32_ipcc_set_bits(void __iomem *reg, u32 mask) +{ + writel_relaxed(readl_relaxed(reg) | mask, reg); +} + +static inline void stm32_ipcc_clr_bits(void __iomem *reg, u32 mask) +{ + writel_relaxed(readl_relaxed(reg) & ~mask, reg); +} + +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->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->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 int chan = (unsigned int)link->con_priv; + struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc, + controller); + + dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan); + + /* set channel n occupied */ + stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan)); + + /* unmask 'tx channel free' interrupt */ + stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, TX_BIT_CHAN(chan)); + + return 0; +} + +static int stm32_ipcc_startup(struct mbox_chan *link) +{ + unsigned int chan = (unsigned int)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->reg_proc + IPCC_XMR, RX_BIT_CHAN(chan)); + + return 0; +} + +static void stm32_ipcc_shutdown(struct mbox_chan *link) +{ + unsigned int chan = (unsigned int)link->con_priv; + struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc, + controller); + + /* mask rx/tx interrupt */ + stm32_ipcc_set_bits(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; + struct resource *res; + unsigned int 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; + + /* 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 */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ipcc->reg_base = devm_ioremap_resource(dev, res); + 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] = of_irq_get_byname(dev->of_node, irq_name[i]); + if (ipcc->irqs[i] < 0) { + dev_err(dev, "no IRQ specified %s\n", irq_name[i]); + 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 %d (%d)\n", i, ret); + goto err_clk; + } + } + + /* mask and enable rx/tx irq */ + stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR, + RX_BIT_MASK | TX_BIT_MASK); + stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XCR, XCR_RXOIE | XCR_TXOIE); + + /* wakeup */ + if (of_property_read_bool(np, "wakeup-source")) { + ipcc->wkp = of_irq_get_byname(dev->of_node, "wakeup"); + if (ipcc->wkp < 0) { + dev_err(dev, "could not get wakeup IRQ\n"); + ret = ipcc->wkp; + goto err_clk; + } + + device_init_wakeup(dev, true); + ret = dev_pm_set_dedicated_wake_irq(dev, ipcc->wkp); + if (ret) { + dev_err(dev, "Failed to set wake up irq\n"); + goto err_init_wkp; + } + } else { + device_init_wakeup(dev, false); + } + + /* 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 = mbox_controller_register(&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 (ipcc->wkp) + dev_pm_clear_wake_irq(dev); +err_init_wkp: + device_init_wakeup(dev, false); +err_clk: + clk_disable_unprepare(ipcc->clk); + return ret; +} + +static int stm32_ipcc_remove(struct platform_device *pdev) +{ + struct stm32_ipcc *ipcc = platform_get_drvdata(pdev); + + mbox_controller_unregister(&ipcc->controller); + + if (ipcc->wkp) + dev_pm_clear_wake_irq(&pdev->dev); + + device_init_wakeup(&pdev->dev, false); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static void stm32_ipcc_set_irq_wake(struct device *dev, bool enable) +{ + struct stm32_ipcc *ipcc = dev_get_drvdata(dev); + unsigned int i; + + if (device_may_wakeup(dev)) + for (i = 0; i < IPCC_IRQ_NUM; i++) + irq_set_irq_wake(ipcc->irqs[i], enable); +} + +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); + + stm32_ipcc_set_irq_wake(dev, true); + + return 0; +} + +static int stm32_ipcc_resume(struct device *dev) +{ + struct stm32_ipcc *ipcc = dev_get_drvdata(dev); + + stm32_ipcc_set_irq_wake(dev, false); + + 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"); |