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>
This commit is contained in:
Fabien Dessenne 2018-05-31 10:27:25 +02:00 committed by Jassi Brar
parent 8f51bb7cae
commit ffbded7dee
3 changed files with 412 additions and 0 deletions

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@ -177,4 +177,12 @@ config BCM_FLEXRM_MBOX
Mailbox implementation of the Broadcom FlexRM ring manager, Mailbox implementation of the Broadcom FlexRM ring manager,
which provides access to various offload engines on Broadcom which provides access to various offload engines on Broadcom
SoCs. Say Y here if you want to use the Broadcom FlexRM. 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 endif

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@ -38,3 +38,5 @@ obj-$(CONFIG_BCM_FLEXRM_MBOX) += bcm-flexrm-mailbox.o
obj-$(CONFIG_QCOM_APCS_IPC) += qcom-apcs-ipc-mailbox.o obj-$(CONFIG_QCOM_APCS_IPC) += qcom-apcs-ipc-mailbox.o
obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o

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@ -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");