diff mbox series

[v4,05/13] peci: Add peci-aspeed controller driver

Message ID 20211123140706.2945700-6-iwona.winiarska@intel.com (mailing list archive)
State New, archived
Headers show
Series Introduce PECI subsystem | expand

Commit Message

Winiarska, Iwona Nov. 23, 2021, 2:06 p.m. UTC
From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>

ASPEED AST24xx/AST25xx/AST26xx SoCs support the PECI electrical
interface (a.k.a PECI wire) that provides a communication channel with
Intel processors.
This driver allows BMC to discover devices connected to it and
communicate with them using PECI protocol.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Co-developed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 MAINTAINERS                           |   8 +
 drivers/peci/Kconfig                  |   6 +
 drivers/peci/Makefile                 |   3 +
 drivers/peci/controller/Kconfig       |  17 +
 drivers/peci/controller/Makefile      |   3 +
 drivers/peci/controller/peci-aspeed.c | 429 ++++++++++++++++++++++++++
 6 files changed, 466 insertions(+)
 create mode 100644 drivers/peci/controller/Kconfig
 create mode 100644 drivers/peci/controller/Makefile
 create mode 100644 drivers/peci/controller/peci-aspeed.c

Comments

Billy Tsai Dec. 6, 2021, 5:27 a.m. UTC | #1
Hi,

After reviewing the patch, I have some suggestions for you. Please see the reply inline.

On 2021/11/23, 10:11 PM, "openbmc on behalf of Iwona Winiarska" <openbmc-bounces+billy_tsai=aspeedtech.com@lists.ozlabs.org on behalf of iwona.winiarska@intel.com> wrote:

    >   From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Add the define for the bus frequency
        #define ASPEED_PECI_BUS_FREQUENCY_MIN		2000
        #define ASPEED_PECI_BUS_FREQUENCY_DEFAULT	2000
        #define ASPEED_PECI_BUS_FREQUENCY_MAX		1000000

   >   +struct aspeed_peci {
    >   +	struct peci_controller *controller;
    >   +	struct device *dev;
    >   +	void __iomem *base;
    >   +	struct clk *clk;
    >   +	struct reset_control *rst;
    >   +	int irq;
    >   +	spinlock_t lock; /* to sync completion status handling */
    >   +	struct completion xfer_complete;
    >   +	u32 status;
    >   +	u32 cmd_timeout_ms;
    >   +	u32 msg_timing;
    >   +	u32 addr_timing;
    >   +	u32 rd_sampling_point;
    >   +	u32 clk_div;

Add the paremeter to store the bus_freq from the dts property
        u32 bus_freq;

    >   +};
    >   +
    >   +static void aspeed_peci_init_regs(struct aspeed_peci *priv)
    >   +{
    >   +	u32 val;
    >   +
    >   +	val = FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, ASPEED_PECI_CLK_DIV_DEFAULT);
    >   +	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
    >   +	writel(val, priv->base + ASPEED_PECI_CTRL);
    >   +	/*
    >   +	 * Timing negotiation period setting.
    >   +	 * The unit of the programmed value is 4 times of PECI clock period.
    >   +	 */
    >   +	val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, priv->msg_timing);
    >   +	val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, priv->addr_timing);
    >   +	writel(val, priv->base + ASPEED_PECI_TIMING_NEGOTIATION);
    >   +
    >   +	/* Clear interrupts */
    >   +	val = readl(priv->base + ASPEED_PECI_INT_STS) | ASPEED_PECI_INT_MASK;
    >   +	writel(val, priv->base + ASPEED_PECI_INT_STS);
    >   +
    >   +	/* Set timing negotiation mode and enable interrupts */
    >   +	val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO);
    >   +	val |= ASPEED_PECI_INT_MASK;
    >   +	writel(val, priv->base + ASPEED_PECI_INT_CTRL);
    >   +
    >   +	val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, priv->rd_sampling_point);
    >   +	val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, priv->clk_div);
    >   +	val |= ASPEED_PECI_CTRL_PECI_EN;
    >   +	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
    >   +	writel(val, priv->base + ASPEED_PECI_CTRL);
    >   +}
    >   +
    >   +static inline int aspeed_peci_check_idle(struct aspeed_peci *priv)
    >   +{
    >   +	u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD);
    >   +
    >   +	if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts) == ASPEED_PECI_CMD_STS_ADDR_T_NEGO)
    >   +		aspeed_peci_init_regs(priv);

As long as the state is not idle, the controller need to reinitialize the PECI register for solving the PECI controller hang.
Before ast2600A3, the controller should assert/de-assert the reset for solving the hang issue.
For backward compatible, I suggest to add the reset assert/de-assert in this place.
        if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) {
                        reset_control_assert(priv->rst);
                        reset_control_deassert(priv->rst);
                        aspeed_peci_init_regs(priv);
        }

    >   +	return readl_poll_timeout(priv->base + ASPEED_PECI_CMD,
    >   +				  cmd_sts,
    >   +				  !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK),
    >   +				  ASPEED_PECI_IDLE_CHECK_INTERVAL_US,
    >   +				  ASPEED_PECI_IDLE_CHECK_TIMEOUT_US);
    >   +}
    >   +
    >   +static int aspeed_peci_xfer(struct peci_controller *controller,
    >   +			    u8 addr, struct peci_request *req)
    >   +{
    >   +	struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent);
    >   +	unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
    >   +	u32 peci_head;
    >   +	int ret;
    >   +
    >   +	if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX ||
    >   +	    req->rx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX)
    >   +		return -EINVAL;
    >   +
    >   +	/* Check command sts and bus idle state */
    >   +	ret = aspeed_peci_check_idle(priv);
    >   +	if (ret)
    >   +		return ret; /* -ETIMEDOUT */
    >   +
    >   +	spin_lock_irq(&priv->lock);
    >   +	reinit_completion(&priv->xfer_complete);
    >   +
    >   +	peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) |
    >   +		    FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) |
    >   +		    FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len);
    >   +
    >   +	writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH);
    >   +
    >   +	memcpy_toio(priv->base + ASPEED_PECI_WR_DATA0, req->tx.buf, min_t(u8, req->tx.len, 16));
    >   +	if (req->tx.len > 16)
    >   +		memcpy_toio(priv->base + ASPEED_PECI_WR_DATA4, req->tx.buf + 16,
    >   +			    req->tx.len - 16);
    >   +
    >   +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
    >   +	dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head);
    >   +	print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len);
    >   +#endif
    >   +	priv->status = 0;
    >   +	writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD);
    >   +	spin_unlock_irq(&priv->lock);
    >   +
    >   +	ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout);
    >   +	if (ret < 0)
    >   +		return ret;
    >   +
    >   +	if (ret == 0) {
    >   +		dev_dbg(priv->dev, "Timeout waiting for a response!\n");
dev_err?
    >   +		return -ETIMEDOUT;
    >   +	}
    >   +
    >   +	spin_lock_irq(&priv->lock);
    >   +
    >   +	if (priv->status != ASPEED_PECI_INT_CMD_DONE) {
    >   +		spin_unlock_irq(&priv->lock);
    >   +		dev_dbg(priv->dev, "No valid response, status: %#02x\n", priv->status);
dev_err?
    >   +		return -EIO;
    >   +	}
    >   +
    >   +	spin_unlock_irq(&priv->lock);
    >   +
    >   +	memcpy_fromio(req->rx.buf, priv->base + ASPEED_PECI_RD_DATA0, min_t(u8, req->rx.len, 16));
    >   +	if (req->rx.len > 16)
    >   +		memcpy_fromio(req->rx.buf + 16, priv->base + ASPEED_PECI_RD_DATA4,
    >   +			      req->rx.len - 16);
    >   +
    >   +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
    >   +	print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len);
    >   +#endif
    >   +	return 0;
    >   +}
    >   +
    >   +static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg)
    >   +{
    >   +	struct aspeed_peci *priv = arg;
    >   +	u32 status;
    >   +
    >   +	spin_lock(&priv->lock);
    >   +	status = readl(priv->base + ASPEED_PECI_INT_STS);
    >   +	writel(status, priv->base + ASPEED_PECI_INT_STS);
    >   +	priv->status |= (status & ASPEED_PECI_INT_MASK);
    >   +
    >   +	/*
    >   +	 * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit
    >   +	 * set even in an error case.
    >   +	 */
    >   +	if (status & ASPEED_PECI_INT_CMD_DONE)
    >   +		complete(&priv->xfer_complete);
    >   +
    >   +	writel(0, priv->base + ASPEED_PECI_CMD);
    >   +
    >   +	spin_unlock(&priv->lock);
    >   +
    >   +	return IRQ_HANDLED;
    >   +}
    >   +
    >   +static void aspeed_peci_property_sanitize(struct device *dev, const char *propname,
    >   +					  u32 min, u32 max, u32 default_val, u32 *propval)
    >   +{
    >   +	u32 val;
    >   +	int ret;
    >   +
    >   +	ret = device_property_read_u32(dev, propname, &val);
    >   +	if (ret) {
    >   +		val = default_val;
    >   +	} else if (val > max || val < min) {
    >   +		dev_warn(dev, "Invalid %s: %u, falling back to: %u\n",
    >   +			 propname, val, default_val);
    >   +
    >   +		val = default_val;
    >   +	}
    >   +
    >   +	*propval = val;
    >   +}
    >   +
    >   +static void aspeed_peci_property_setup(struct aspeed_peci *priv)
    >   +{
    >   +	aspeed_peci_property_sanitize(priv->dev, "aspeed,clock-divider",
    >   +				      0, ASPEED_PECI_CLK_DIV_MAX,
    >   +				      ASPEED_PECI_CLK_DIV_DEFAULT, &priv->clk_div);
    >   +	aspeed_peci_property_sanitize(priv->dev, "aspeed,msg-timing",
    >   +				      0, ASPEED_PECI_MSG_TIMING_MAX,
    >   +				      ASPEED_PECI_MSG_TIMING_DEFAULT, &priv->msg_timing);
    >   +	aspeed_peci_property_sanitize(priv->dev, "aspeed,addr-timing",
    >   +				      0, ASPEED_PECI_ADDR_TIMING_MAX,
    >   +				      ASPEED_PECI_ADDR_TIMING_DEFAULT, &priv->addr_timing);

Use the bus-frequency to replace the property above:
        aspeed_peci_property_sanitize(priv->dev, "bus-frequency",
				ASPEED_PECI_BUS_FREQUENCY_MIN, ASPEED_PECI_BUS_FREQUENCY_MAX,
				ASPEED_PECI_BUS_FREQUENCY_DEFAULT, &priv->bus_freq);

    >   +	aspeed_peci_property_sanitize(priv->dev, "aspeed,rd-sampling-point",
    >   +				      0, ASPEED_PECI_RD_SAMPLING_POINT_MAX,
    >   +				      ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT,
    >   +				      &priv->rd_sampling_point);
    >   +	aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms",
    >   +				      1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX,
    >   +				      ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms);
    >   +}
Add the function of automatically calculating the settings to adapt to the bus frequency.
        static void aspeed_peci_bus_freq_setup(struct aspeed_peci *priv)
        {
                unsigned long src_clk_rate;
                int delta_value, delta_tmp, clk_divisor, clk_divisor_tmp;
                u32 msg_timing, clk_div;

                src_clk_rate = clk_get_rate(priv->clk);

                /*
                 * PECI bus freq  = (source clk rate) / (4 * (PECI04[15:8]*4+1) * (1 << PECI00[10:8]))
                 * (1 << PECI00[10:8]) * (PECI04[15:8]*4+1) = (source clk rate) / (4 * PECI bus freq )
                 */
                clk_divisor = src_clk_rate / (4 * priv->bus_freq);
                delta_value = clk_divisor;
                /* Find the closest divisor for bus-frequency */
                for (msg_timing = 1; msg_timing <= 255; msg_timing++)
                        for (clk_div = 0; clk_div < 7;
                                clk_div++) {
                                clk_divisor_tmp = (1 << clk_div) *
                                                (msg_timing * 4 + 1);
                                delta_tmp = abs(clk_divisor - clk_divisor_tmp);
                                if (delta_tmp < delta_value) {
                                        delta_value = delta_tmp;
                                        priv->msg_timing = msg_timing;
                                        priv->addr_timing = priv->msg_timing;
                                        priv->clk_div = clk_div;
                                }
                        }
        }

    >   +
    >   +static struct peci_controller_ops aspeed_ops = {
    >   +	.xfer = aspeed_peci_xfer,
    >   +};
    >   +
    >   +static void aspeed_peci_reset_control_release(void *data)
    >   +{
    >   +	reset_control_assert(data);
    >   +}
    >   +
    >   +static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst)
    >   +{
    >   +	int ret;
    >   +
    >   +	ret = reset_control_deassert(rst);
    >   +	if (ret)
    >   +		return ret;
    >   +
    >   +	return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst);
    >   +}
    >   +
    >   +static void aspeed_peci_clk_release(void *data)
    >   +{
    >   +	clk_disable_unprepare(data);
    >   +}
    >   +
    >   +static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk)
    >   +{
    >   +	int ret;
    >   +
    >   +	ret = clk_prepare_enable(clk);
    >   +	if (ret)
    >   +		return ret;
    >   +
    >   +	return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk);
    >   +}
    >   +
    >   +static int aspeed_peci_probe(struct platform_device *pdev)
    >   +{
    >   +	struct peci_controller *controller;
    >   +	struct aspeed_peci *priv;
    >   +	int ret;
    >   +
    >   +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
    >   +	if (!priv)
    >   +		return -ENOMEM;
    >   +
    >   +	priv->dev = &pdev->dev;
    >   +	dev_set_drvdata(priv->dev, priv);
    >   +
    >   +	priv->base = devm_platform_ioremap_resource(pdev, 0);
    >   +	if (IS_ERR(priv->base))
    >   +		return PTR_ERR(priv->base);
    >   +
    >   +	priv->irq = platform_get_irq(pdev, 0);
    >   +	if (!priv->irq)
    >   +		return priv->irq;
    >   +
    >   +	ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
    >   +			       0, "peci-aspeed", priv);
    >   +	if (ret)
    >   +		return ret;
    >   +
    >   +	init_completion(&priv->xfer_complete);
    >   +	spin_lock_init(&priv->lock);
    >   +
    >   +	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
    >   +	if (IS_ERR(priv->rst))
    >   +		return dev_err_probe(priv->dev, PTR_ERR(priv->rst),
    >   +				     "failed to get reset control\n");
    >   +
    >   +	ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst);
    >   +	if (ret)
    >   +		return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n");
    >   +
    >   +	priv->clk = devm_clk_get(priv->dev, NULL);
    >   +	if (IS_ERR(priv->clk))
    >   +		return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "failed to get clk\n");
    >   +
    >   +	ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk);
    >   +	if (ret)
    >   +		return dev_err_probe(priv->dev, ret, "failed to enable clock\n");
    >   +
    >   +	aspeed_peci_property_setup(priv);

        aspeed_peci_bus_freq_setup(priv);

    >   +
    >   +	aspeed_peci_init_regs(priv);
    >   +
    >   +	controller = devm_peci_controller_add(priv->dev, &aspeed_ops);
    >   +	if (IS_ERR(controller))
    >   +		return dev_err_probe(priv->dev, PTR_ERR(controller),
    >   +				     "failed to add aspeed peci controller\n");
    >   +
    >   +	priv->controller = controller;
    >   +
    >   +	return 0;
    >   +}
    >   +
    >   +static const struct of_device_id aspeed_peci_of_table[] = {
    >   +	{ .compatible = "aspeed,ast2400-peci", },
    >   +	{ .compatible = "aspeed,ast2500-peci", },
    >   +	{ .compatible = "aspeed,ast2600-peci", },
    >   +	{ }
    >   +};
    >   +MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
    >   +
    >   +static struct platform_driver aspeed_peci_driver = {
    >   +	.probe  = aspeed_peci_probe,
    >   +	.driver = {
    >   +		.name           = "peci-aspeed",
    >   +		.of_match_table = aspeed_peci_of_table,
    >   +	},
    >   +};
    >   +module_platform_driver(aspeed_peci_driver);
    >   +
    >   +MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
    >   +MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
    >   +MODULE_DESCRIPTION("ASPEED PECI driver");
    >   +MODULE_LICENSE("GPL");
    >   +MODULE_IMPORT_NS(PECI);
    >   -- 
    >   2.31.1
Winiarska, Iwona Dec. 7, 2021, 6:09 p.m. UTC | #2
On Mon, 2021-12-06 at 05:27 +0000, Billy Tsai wrote:
> Hi,
> 
> After reviewing the patch, I have some suggestions for you. Please see the
> reply inline.
> 
> On 2021/11/23, 10:11 PM, "openbmc on behalf of Iwona Winiarska"
> <openbmc-bounces+billy_tsai=aspeedtech.com@lists.ozlabs.org on behalf of
> iwona.winiarska@intel.com> wrote:
> 
>     >   From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> Add the define for the bus frequency
>         #define ASPEED_PECI_BUS_FREQUENCY_MIN           2000
>         #define ASPEED_PECI_BUS_FREQUENCY_DEFAULT       2000
>         #define ASPEED_PECI_BUS_FREQUENCY_MAX           1000000
> 
>    >   +struct aspeed_peci {
>     >   +       struct peci_controller *controller;
>     >   +       struct device *dev;
>     >   +       void __iomem *base;
>     >   +       struct clk *clk;
>     >   +       struct reset_control *rst;
>     >   +       int irq;
>     >   +       spinlock_t lock; /* to sync completion status handling */
>     >   +       struct completion xfer_complete;
>     >   +       u32 status;
>     >   +       u32 cmd_timeout_ms;
>     >   +       u32 msg_timing;
>     >   +       u32 addr_timing;
>     >   +       u32 rd_sampling_point;
>     >   +       u32 clk_div;
> 
> Add the paremeter to store the bus_freq from the dts property
>         u32 bus_freq;
> 
>     >   +};
>     >   +
>     >   +static void aspeed_peci_init_regs(struct aspeed_peci *priv)
>     >   +{
>     >   +       u32 val;
>     >   +
>     >   +       val = FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK,
> ASPEED_PECI_CLK_DIV_DEFAULT);
>     >   +       val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
>     >   +       writel(val, priv->base + ASPEED_PECI_CTRL);
>     >   +       /*
>     >   +        * Timing negotiation period setting.
>     >   +        * The unit of the programmed value is 4 times of PECI clock
> period.
>     >   +        */
>     >   +       val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, priv-
> >msg_timing);
>     >   +       val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, priv-
> >addr_timing);
>     >   +       writel(val, priv->base + ASPEED_PECI_TIMING_NEGOTIATION);
>     >   +
>     >   +       /* Clear interrupts */
>     >   +       val = readl(priv->base + ASPEED_PECI_INT_STS) |
> ASPEED_PECI_INT_MASK;
>     >   +       writel(val, priv->base + ASPEED_PECI_INT_STS);
>     >   +
>     >   +       /* Set timing negotiation mode and enable interrupts */
>     >   +       val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK,
> ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO);
>     >   +       val |= ASPEED_PECI_INT_MASK;
>     >   +       writel(val, priv->base + ASPEED_PECI_INT_CTRL);
>     >   +
>     >   +       val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, priv-
> >rd_sampling_point);
>     >   +       val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, priv-
> >clk_div);
>     >   +       val |= ASPEED_PECI_CTRL_PECI_EN;
>     >   +       val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
>     >   +       writel(val, priv->base + ASPEED_PECI_CTRL);
>     >   +}
>     >   +
>     >   +static inline int aspeed_peci_check_idle(struct aspeed_peci *priv)
>     >   +{
>     >   +       u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD);
>     >   +
>     >   +       if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts) ==
> ASPEED_PECI_CMD_STS_ADDR_T_NEGO)
>     >   +               aspeed_peci_init_regs(priv);
> 
> As long as the state is not idle, the controller need to reinitialize the PECI
> register for solving the PECI controller hang.
> Before ast2600A3, the controller should assert/de-assert the reset for solving
> the hang issue.
> For backward compatible, I suggest to add the reset assert/de-assert in this
> place.
>         if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) {
>                         reset_control_assert(priv->rst);
>                         reset_control_deassert(priv->rst);
>                         aspeed_peci_init_regs(priv);
>         }

Ack.

> 

(...)

>     >   +static void aspeed_peci_property_setup(struct aspeed_peci *priv)
>     >   +{
>     >   +       aspeed_peci_property_sanitize(priv->dev, "aspeed,clock-
> divider",
>     >   +                                     0, ASPEED_PECI_CLK_DIV_MAX,
>     >   +                                     ASPEED_PECI_CLK_DIV_DEFAULT,
> &priv->clk_div);
>     >   +       aspeed_peci_property_sanitize(priv->dev, "aspeed,msg-timing",
>     >   +                                     0, ASPEED_PECI_MSG_TIMING_MAX,
>     >   +                                     ASPEED_PECI_MSG_TIMING_DEFAULT,
> &priv->msg_timing);
>     >   +       aspeed_peci_property_sanitize(priv->dev, "aspeed,addr-timing",
>     >   +                                     0, ASPEED_PECI_ADDR_TIMING_MAX,
>     >   +                                     ASPEED_PECI_ADDR_TIMING_DEFAULT,
> &priv->addr_timing);
> 
> Use the bus-frequency to replace the property above:
>         aspeed_peci_property_sanitize(priv->dev, "bus-frequency",
>                                 ASPEED_PECI_BUS_FREQUENCY_MIN,
> ASPEED_PECI_BUS_FREQUENCY_MAX,
>                                 ASPEED_PECI_BUS_FREQUENCY_DEFAULT, &priv-
> >bus_freq);
> 
>     >   +       aspeed_peci_property_sanitize(priv->dev, "aspeed,rd-sampling-
> point",
>     >   +                                     0,
> ASPEED_PECI_RD_SAMPLING_POINT_MAX,
>     >   +                                    
> ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT,
>     >   +                                     &priv->rd_sampling_point);
>     >   +       aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms",
>     >   +                                     1,
> ASPEED_PECI_CMD_TIMEOUT_MS_MAX,
>     >   +                                    
> ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms);
>     >   +}
> Add the function of automatically calculating the settings to adapt to the bus
> frequency.

If we want to go with exposing "bus-frequency", instead of hardware properties,
I don't think we should opencode it in this way.
Rather, we should expose it as a clock, passing "clock-frequency" property via
DTS and exposing it using struct clk_hw.
We would then just call clock API (clk_round_rate / clk_set_rate etc),
presenting this as what it actually is (a "custom" clock divider).

Thanks
-Iwona

>         static void aspeed_peci_bus_freq_setup(struct aspeed_peci *priv)
>         {
>                 unsigned long src_clk_rate;
>                 int delta_value, delta_tmp, clk_divisor, clk_divisor_tmp;
>                 u32 msg_timing, clk_div;
> 
>                 src_clk_rate = clk_get_rate(priv->clk);
> 
>                 /*
>                  * PECI bus freq  = (source clk rate) / (4 *
> (PECI04[15:8]*4+1) * (1 << PECI00[10:8]))
>                  * (1 << PECI00[10:8]) * (PECI04[15:8]*4+1) = (source clk
> rate) / (4 * PECI bus freq )
>                  */
>                 clk_divisor = src_clk_rate / (4 * priv->bus_freq);
>                 delta_value = clk_divisor;
>                 /* Find the closest divisor for bus-frequency */
>                 for (msg_timing = 1; msg_timing <= 255; msg_timing++)
>                         for (clk_div = 0; clk_div < 7;
>                                 clk_div++) {
>                                 clk_divisor_tmp = (1 << clk_div) *
>                                                 (msg_timing * 4 + 1);
>                                 delta_tmp = abs(clk_divisor -
> clk_divisor_tmp);
>                                 if (delta_tmp < delta_value) {
>                                         delta_value = delta_tmp;
>                                         priv->msg_timing = msg_timing;
>                                         priv->addr_timing = priv->msg_timing;
>                                         priv->clk_div = clk_div;
>                                 }
>                         }
>         }
> 
>     >   +
>     >   +static struct peci_controller_ops aspeed_ops = {
>     >   +       .xfer = aspeed_peci_xfer,
>     >   +};
>     >   +
>     >   +static void aspeed_peci_reset_control_release(void *data)
>     >   +{
>     >   +       reset_control_assert(data);
>     >   +}
>     >   +
>     >   +static int devm_aspeed_peci_reset_control_deassert(struct device
> *dev, struct reset_control *rst)
>     >   +{
>     >   +       int ret;
>     >   +
>     >   +       ret = reset_control_deassert(rst);
>     >   +       if (ret)
>     >   +               return ret;
>     >   +
>     >   +       return devm_add_action_or_reset(dev,
> aspeed_peci_reset_control_release, rst);
>     >   +}
>     >   +
>     >   +static void aspeed_peci_clk_release(void *data)
>     >   +{
>     >   +       clk_disable_unprepare(data);
>     >   +}
>     >   +
>     >   +static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk
> *clk)
>     >   +{
>     >   +       int ret;
>     >   +
>     >   +       ret = clk_prepare_enable(clk);
>     >   +       if (ret)
>     >   +               return ret;
>     >   +
>     >   +       return devm_add_action_or_reset(dev, aspeed_peci_clk_release,
> clk);
>     >   +}
>     >   +
>     >   +static int aspeed_peci_probe(struct platform_device *pdev)
>     >   +{
>     >   +       struct peci_controller *controller;
>     >   +       struct aspeed_peci *priv;
>     >   +       int ret;
>     >   +
>     >   +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>     >   +       if (!priv)
>     >   +               return -ENOMEM;
>     >   +
>     >   +       priv->dev = &pdev->dev;
>     >   +       dev_set_drvdata(priv->dev, priv);
>     >   +
>     >   +       priv->base = devm_platform_ioremap_resource(pdev, 0);
>     >   +       if (IS_ERR(priv->base))
>     >   +               return PTR_ERR(priv->base);
>     >   +
>     >   +       priv->irq = platform_get_irq(pdev, 0);
>     >   +       if (!priv->irq)
>     >   +               return priv->irq;
>     >   +
>     >   +       ret = devm_request_irq(&pdev->dev, priv->irq,
> aspeed_peci_irq_handler,
>     >   +                              0, "peci-aspeed", priv);
>     >   +       if (ret)
>     >   +               return ret;
>     >   +
>     >   +       init_completion(&priv->xfer_complete);
>     >   +       spin_lock_init(&priv->lock);
>     >   +
>     >   +       priv->rst = devm_reset_control_get(&pdev->dev, NULL);
>     >   +       if (IS_ERR(priv->rst))
>     >   +               return dev_err_probe(priv->dev, PTR_ERR(priv->rst),
>     >   +                                    "failed to get reset control\n");
>     >   +
>     >   +       ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv-
> >rst);
>     >   +       if (ret)
>     >   +               return dev_err_probe(priv->dev, ret, "cannot deassert
> reset control\n");
>     >   +
>     >   +       priv->clk = devm_clk_get(priv->dev, NULL);
>     >   +       if (IS_ERR(priv->clk))
>     >   +               return dev_err_probe(priv->dev, PTR_ERR(priv->clk),
> "failed to get clk\n");
>     >   +
>     >   +       ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk);
>     >   +       if (ret)
>     >   +               return dev_err_probe(priv->dev, ret, "failed to enable
> clock\n");
>     >   +
>     >   +       aspeed_peci_property_setup(priv);
> 
>         aspeed_peci_bus_freq_setup(priv);
> 
>     >   +
>     >   +       aspeed_peci_init_regs(priv);
>     >   +
>     >   +       controller = devm_peci_controller_add(priv->dev, &aspeed_ops);
>     >   +       if (IS_ERR(controller))
>     >   +               return dev_err_probe(priv->dev, PTR_ERR(controller),
>     >   +                                    "failed to add aspeed peci
> controller\n");
>     >   +
>     >   +       priv->controller = controller;
>     >   +
>     >   +       return 0;
>     >   +}
>     >   +
>     >   +static const struct of_device_id aspeed_peci_of_table[] = {
>     >   +       { .compatible = "aspeed,ast2400-peci", },
>     >   +       { .compatible = "aspeed,ast2500-peci", },
>     >   +       { .compatible = "aspeed,ast2600-peci", },
>     >   +       { }
>     >   +};
>     >   +MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
>     >   +
>     >   +static struct platform_driver aspeed_peci_driver = {
>     >   +       .probe  = aspeed_peci_probe,
>     >   +       .driver = {
>     >   +               .name           = "peci-aspeed",
>     >   +               .of_match_table = aspeed_peci_of_table,
>     >   +       },
>     >   +};
>     >   +module_platform_driver(aspeed_peci_driver);
>     >   +
>     >   +MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
>     >   +MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
>     >   +MODULE_DESCRIPTION("ASPEED PECI driver");
>     >   +MODULE_LICENSE("GPL");
>     >   +MODULE_IMPORT_NS(PECI);
>     >   -- 
>     >   2.31.1
> 
> 
>
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index a638be585207..093319d9b994 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2945,6 +2945,14 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/net/asix,ax88796c.yaml
 F:	drivers/net/ethernet/asix/ax88796c_*
 
+ASPEED PECI CONTROLLER
+M:	Iwona Winiarska <iwona.winiarska@intel.com>
+L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
+L:	openbmc@lists.ozlabs.org (moderated for non-subscribers)
+S:	Supported
+F:	Documentation/devicetree/bindings/peci/peci-aspeed.yaml
+F:	drivers/peci/controller/peci-aspeed.c
+
 ASPEED PINCTRL DRIVERS
 M:	Andrew Jeffery <andrew@aj.id.au>
 L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
diff --git a/drivers/peci/Kconfig b/drivers/peci/Kconfig
index 71a4ad81225a..99279df97a78 100644
--- a/drivers/peci/Kconfig
+++ b/drivers/peci/Kconfig
@@ -13,3 +13,9 @@  menuconfig PECI
 
 	  This support is also available as a module. If so, the module
 	  will be called peci.
+
+if PECI
+
+source "drivers/peci/controller/Kconfig"
+
+endif # PECI
diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile
index e789a354e842..926d8df15cbd 100644
--- a/drivers/peci/Makefile
+++ b/drivers/peci/Makefile
@@ -3,3 +3,6 @@ 
 # Core functionality
 peci-y := core.o
 obj-$(CONFIG_PECI) += peci.o
+
+# Hardware specific bus drivers
+obj-y += controller/
diff --git a/drivers/peci/controller/Kconfig b/drivers/peci/controller/Kconfig
new file mode 100644
index 000000000000..3008b1b81049
--- /dev/null
+++ b/drivers/peci/controller/Kconfig
@@ -0,0 +1,17 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+
+config PECI_ASPEED
+	tristate "ASPEED PECI support"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on OF
+	depends on HAS_IOMEM
+	help
+	  This option enables PECI controller driver for ASPEED AST2400,
+	  AST2500 and AST2600 SoCs. It allows BMC to discover devices
+	  connected to it, and communicate with them using PECI protocol.
+
+	  Say Y here if your system runs on ASPEED SoC and you are using it
+	  as BMC for Intel platform.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called peci-aspeed.
diff --git a/drivers/peci/controller/Makefile b/drivers/peci/controller/Makefile
new file mode 100644
index 000000000000..022c28ef1bf0
--- /dev/null
+++ b/drivers/peci/controller/Makefile
@@ -0,0 +1,3 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PECI_ASPEED)	+= peci-aspeed.o
diff --git a/drivers/peci/controller/peci-aspeed.c b/drivers/peci/controller/peci-aspeed.c
new file mode 100644
index 000000000000..86c5f13508c1
--- /dev/null
+++ b/drivers/peci/controller/peci-aspeed.c
@@ -0,0 +1,429 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2012-2017 ASPEED Technology Inc.
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/* ASPEED PECI Registers */
+/* Control Register */
+#define ASPEED_PECI_CTRL			0x00
+#define   ASPEED_PECI_CTRL_SAMPLING_MASK	GENMASK(19, 16)
+#define   ASPEED_PECI_CTRL_RD_MODE_MASK		GENMASK(13, 12)
+#define     ASPEED_PECI_CTRL_RD_MODE_DBG	BIT(13)
+#define     ASPEED_PECI_CTRL_RD_MODE_COUNT	BIT(12)
+#define   ASPEED_PECI_CTRL_CLK_SOURCE		BIT(11)
+#define   ASPEED_PECI_CTRL_CLK_DIV_MASK		GENMASK(10, 8)
+#define   ASPEED_PECI_CTRL_INVERT_OUT		BIT(7)
+#define   ASPEED_PECI_CTRL_INVERT_IN		BIT(6)
+#define   ASPEED_PECI_CTRL_BUS_CONTENTION_EN	BIT(5)
+#define   ASPEED_PECI_CTRL_PECI_EN		BIT(4)
+#define   ASPEED_PECI_CTRL_PECI_CLK_EN		BIT(0)
+
+/* Timing Negotiation Register */
+#define ASPEED_PECI_TIMING_NEGOTIATION		0x04
+#define   ASPEED_PECI_T_NEGO_MSG_MASK		GENMASK(15, 8)
+#define   ASPEED_PECI_T_NEGO_ADDR_MASK		GENMASK(7, 0)
+
+/* Command Register */
+#define ASPEED_PECI_CMD				0x08
+#define   ASPEED_PECI_CMD_PIN_MONITORING	BIT(31)
+#define   ASPEED_PECI_CMD_STS_MASK		GENMASK(27, 24)
+#define     ASPEED_PECI_CMD_STS_ADDR_T_NEGO	0x3
+#define   ASPEED_PECI_CMD_IDLE_MASK		\
+	  (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MONITORING)
+#define   ASPEED_PECI_CMD_FIRE			BIT(0)
+
+/* Read/Write Length Register */
+#define ASPEED_PECI_RW_LENGTH			0x0c
+#define   ASPEED_PECI_AW_FCS_EN			BIT(31)
+#define   ASPEED_PECI_RD_LEN_MASK		GENMASK(23, 16)
+#define   ASPEED_PECI_WR_LEN_MASK		GENMASK(15, 8)
+#define   ASPEED_PECI_TARGET_ADDR_MASK		GENMASK(7, 0)
+
+/* Expected FCS Data Register */
+#define ASPEED_PECI_EXPECTED_FCS		0x10
+#define   ASPEED_PECI_EXPECTED_RD_FCS_MASK	GENMASK(23, 16)
+#define   ASPEED_PECI_EXPECTED_AW_FCS_AUTO_MASK	GENMASK(15, 8)
+#define   ASPEED_PECI_EXPECTED_WR_FCS_MASK	GENMASK(7, 0)
+
+/* Captured FCS Data Register */
+#define ASPEED_PECI_CAPTURED_FCS		0x14
+#define   ASPEED_PECI_CAPTURED_RD_FCS_MASK	GENMASK(23, 16)
+#define   ASPEED_PECI_CAPTURED_WR_FCS_MASK	GENMASK(7, 0)
+
+/* Interrupt Register */
+#define ASPEED_PECI_INT_CTRL			0x18
+#define   ASPEED_PECI_TIMING_NEGO_SEL_MASK	GENMASK(31, 30)
+#define     ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO	0
+#define     ASPEED_PECI_2ND_BIT_OF_ADDR_NEGO	1
+#define     ASPEED_PECI_MESSAGE_NEGO		2
+#define   ASPEED_PECI_INT_MASK			GENMASK(4, 0)
+#define     ASPEED_PECI_INT_BUS_TIMEOUT		BIT(4)
+#define     ASPEED_PECI_INT_BUS_CONTENTION	BIT(3)
+#define     ASPEED_PECI_INT_WR_FCS_BAD		BIT(2)
+#define     ASPEED_PECI_INT_WR_FCS_ABORT	BIT(1)
+#define     ASPEED_PECI_INT_CMD_DONE		BIT(0)
+
+/* Interrupt Status Register */
+#define ASPEED_PECI_INT_STS			0x1c
+#define   ASPEED_PECI_INT_TIMING_RESULT_MASK	GENMASK(29, 16)
+	  /* bits[4..0]: Same bit fields in the 'Interrupt Register' */
+
+/* Rx/Tx Data Buffer Registers */
+#define ASPEED_PECI_WR_DATA0			0x20
+#define ASPEED_PECI_WR_DATA1			0x24
+#define ASPEED_PECI_WR_DATA2			0x28
+#define ASPEED_PECI_WR_DATA3			0x2c
+#define ASPEED_PECI_RD_DATA0			0x30
+#define ASPEED_PECI_RD_DATA1			0x34
+#define ASPEED_PECI_RD_DATA2			0x38
+#define ASPEED_PECI_RD_DATA3			0x3c
+#define ASPEED_PECI_WR_DATA4			0x40
+#define ASPEED_PECI_WR_DATA5			0x44
+#define ASPEED_PECI_WR_DATA6			0x48
+#define ASPEED_PECI_WR_DATA7			0x4c
+#define ASPEED_PECI_RD_DATA4			0x50
+#define ASPEED_PECI_RD_DATA5			0x54
+#define ASPEED_PECI_RD_DATA6			0x58
+#define ASPEED_PECI_RD_DATA7			0x5c
+#define   ASPEED_PECI_DATA_BUF_SIZE_MAX		32
+
+/* Timing Negotiation */
+#define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT	8
+#define ASPEED_PECI_RD_SAMPLING_POINT_MAX	(BIT(4) - 1)
+#define ASPEED_PECI_CLK_DIV_DEFAULT		0
+#define ASPEED_PECI_CLK_DIV_MAX			(BIT(3) - 1)
+#define ASPEED_PECI_MSG_TIMING_DEFAULT		1
+#define ASPEED_PECI_MSG_TIMING_MAX		(BIT(8) - 1)
+#define ASPEED_PECI_ADDR_TIMING_DEFAULT		1
+#define ASPEED_PECI_ADDR_TIMING_MAX		(BIT(8) - 1)
+
+/* Timeout */
+#define ASPEED_PECI_IDLE_CHECK_TIMEOUT_US	(50 * USEC_PER_MSEC)
+#define ASPEED_PECI_IDLE_CHECK_INTERVAL_US	(10 * USEC_PER_MSEC)
+#define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT	(1000)
+#define ASPEED_PECI_CMD_TIMEOUT_MS_MAX		(1000)
+
+struct aspeed_peci {
+	struct peci_controller *controller;
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk;
+	struct reset_control *rst;
+	int irq;
+	spinlock_t lock; /* to sync completion status handling */
+	struct completion xfer_complete;
+	u32 status;
+	u32 cmd_timeout_ms;
+	u32 msg_timing;
+	u32 addr_timing;
+	u32 rd_sampling_point;
+	u32 clk_div;
+};
+
+static void aspeed_peci_init_regs(struct aspeed_peci *priv)
+{
+	u32 val;
+
+	val = FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, ASPEED_PECI_CLK_DIV_DEFAULT);
+	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
+	writel(val, priv->base + ASPEED_PECI_CTRL);
+	/*
+	 * Timing negotiation period setting.
+	 * The unit of the programmed value is 4 times of PECI clock period.
+	 */
+	val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, priv->msg_timing);
+	val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, priv->addr_timing);
+	writel(val, priv->base + ASPEED_PECI_TIMING_NEGOTIATION);
+
+	/* Clear interrupts */
+	val = readl(priv->base + ASPEED_PECI_INT_STS) | ASPEED_PECI_INT_MASK;
+	writel(val, priv->base + ASPEED_PECI_INT_STS);
+
+	/* Set timing negotiation mode and enable interrupts */
+	val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO);
+	val |= ASPEED_PECI_INT_MASK;
+	writel(val, priv->base + ASPEED_PECI_INT_CTRL);
+
+	val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, priv->rd_sampling_point);
+	val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, priv->clk_div);
+	val |= ASPEED_PECI_CTRL_PECI_EN;
+	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
+	writel(val, priv->base + ASPEED_PECI_CTRL);
+}
+
+static inline int aspeed_peci_check_idle(struct aspeed_peci *priv)
+{
+	u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD);
+
+	if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts) == ASPEED_PECI_CMD_STS_ADDR_T_NEGO)
+		aspeed_peci_init_regs(priv);
+
+	return readl_poll_timeout(priv->base + ASPEED_PECI_CMD,
+				  cmd_sts,
+				  !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK),
+				  ASPEED_PECI_IDLE_CHECK_INTERVAL_US,
+				  ASPEED_PECI_IDLE_CHECK_TIMEOUT_US);
+}
+
+static int aspeed_peci_xfer(struct peci_controller *controller,
+			    u8 addr, struct peci_request *req)
+{
+	struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent);
+	unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
+	u32 peci_head;
+	int ret;
+
+	if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX ||
+	    req->rx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX)
+		return -EINVAL;
+
+	/* Check command sts and bus idle state */
+	ret = aspeed_peci_check_idle(priv);
+	if (ret)
+		return ret; /* -ETIMEDOUT */
+
+	spin_lock_irq(&priv->lock);
+	reinit_completion(&priv->xfer_complete);
+
+	peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) |
+		    FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) |
+		    FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len);
+
+	writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH);
+
+	memcpy_toio(priv->base + ASPEED_PECI_WR_DATA0, req->tx.buf, min_t(u8, req->tx.len, 16));
+	if (req->tx.len > 16)
+		memcpy_toio(priv->base + ASPEED_PECI_WR_DATA4, req->tx.buf + 16,
+			    req->tx.len - 16);
+
+#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
+	dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head);
+	print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len);
+#endif
+	priv->status = 0;
+	writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD);
+	spin_unlock_irq(&priv->lock);
+
+	ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout);
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0) {
+		dev_dbg(priv->dev, "Timeout waiting for a response!\n");
+		return -ETIMEDOUT;
+	}
+
+	spin_lock_irq(&priv->lock);
+
+	if (priv->status != ASPEED_PECI_INT_CMD_DONE) {
+		spin_unlock_irq(&priv->lock);
+		dev_dbg(priv->dev, "No valid response, status: %#02x\n", priv->status);
+		return -EIO;
+	}
+
+	spin_unlock_irq(&priv->lock);
+
+	memcpy_fromio(req->rx.buf, priv->base + ASPEED_PECI_RD_DATA0, min_t(u8, req->rx.len, 16));
+	if (req->rx.len > 16)
+		memcpy_fromio(req->rx.buf + 16, priv->base + ASPEED_PECI_RD_DATA4,
+			      req->rx.len - 16);
+
+#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
+	print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len);
+#endif
+	return 0;
+}
+
+static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg)
+{
+	struct aspeed_peci *priv = arg;
+	u32 status;
+
+	spin_lock(&priv->lock);
+	status = readl(priv->base + ASPEED_PECI_INT_STS);
+	writel(status, priv->base + ASPEED_PECI_INT_STS);
+	priv->status |= (status & ASPEED_PECI_INT_MASK);
+
+	/*
+	 * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit
+	 * set even in an error case.
+	 */
+	if (status & ASPEED_PECI_INT_CMD_DONE)
+		complete(&priv->xfer_complete);
+
+	writel(0, priv->base + ASPEED_PECI_CMD);
+
+	spin_unlock(&priv->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void aspeed_peci_property_sanitize(struct device *dev, const char *propname,
+					  u32 min, u32 max, u32 default_val, u32 *propval)
+{
+	u32 val;
+	int ret;
+
+	ret = device_property_read_u32(dev, propname, &val);
+	if (ret) {
+		val = default_val;
+	} else if (val > max || val < min) {
+		dev_warn(dev, "Invalid %s: %u, falling back to: %u\n",
+			 propname, val, default_val);
+
+		val = default_val;
+	}
+
+	*propval = val;
+}
+
+static void aspeed_peci_property_setup(struct aspeed_peci *priv)
+{
+	aspeed_peci_property_sanitize(priv->dev, "aspeed,clock-divider",
+				      0, ASPEED_PECI_CLK_DIV_MAX,
+				      ASPEED_PECI_CLK_DIV_DEFAULT, &priv->clk_div);
+	aspeed_peci_property_sanitize(priv->dev, "aspeed,msg-timing",
+				      0, ASPEED_PECI_MSG_TIMING_MAX,
+				      ASPEED_PECI_MSG_TIMING_DEFAULT, &priv->msg_timing);
+	aspeed_peci_property_sanitize(priv->dev, "aspeed,addr-timing",
+				      0, ASPEED_PECI_ADDR_TIMING_MAX,
+				      ASPEED_PECI_ADDR_TIMING_DEFAULT, &priv->addr_timing);
+	aspeed_peci_property_sanitize(priv->dev, "aspeed,rd-sampling-point",
+				      0, ASPEED_PECI_RD_SAMPLING_POINT_MAX,
+				      ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT,
+				      &priv->rd_sampling_point);
+	aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms",
+				      1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX,
+				      ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms);
+}
+
+static struct peci_controller_ops aspeed_ops = {
+	.xfer = aspeed_peci_xfer,
+};
+
+static void aspeed_peci_reset_control_release(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst)
+{
+	int ret;
+
+	ret = reset_control_deassert(rst);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst);
+}
+
+static void aspeed_peci_clk_release(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk)
+{
+	int ret;
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk);
+}
+
+static int aspeed_peci_probe(struct platform_device *pdev)
+{
+	struct peci_controller *controller;
+	struct aspeed_peci *priv;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+	dev_set_drvdata(priv->dev, priv);
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (!priv->irq)
+		return priv->irq;
+
+	ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
+			       0, "peci-aspeed", priv);
+	if (ret)
+		return ret;
+
+	init_completion(&priv->xfer_complete);
+	spin_lock_init(&priv->lock);
+
+	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->rst))
+		return dev_err_probe(priv->dev, PTR_ERR(priv->rst),
+				     "failed to get reset control\n");
+
+	ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst);
+	if (ret)
+		return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n");
+
+	priv->clk = devm_clk_get(priv->dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "failed to get clk\n");
+
+	ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk);
+	if (ret)
+		return dev_err_probe(priv->dev, ret, "failed to enable clock\n");
+
+	aspeed_peci_property_setup(priv);
+
+	aspeed_peci_init_regs(priv);
+
+	controller = devm_peci_controller_add(priv->dev, &aspeed_ops);
+	if (IS_ERR(controller))
+		return dev_err_probe(priv->dev, PTR_ERR(controller),
+				     "failed to add aspeed peci controller\n");
+
+	priv->controller = controller;
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_peci_of_table[] = {
+	{ .compatible = "aspeed,ast2400-peci", },
+	{ .compatible = "aspeed,ast2500-peci", },
+	{ .compatible = "aspeed,ast2600-peci", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
+
+static struct platform_driver aspeed_peci_driver = {
+	.probe  = aspeed_peci_probe,
+	.driver = {
+		.name           = "peci-aspeed",
+		.of_match_table = aspeed_peci_of_table,
+	},
+};
+module_platform_driver(aspeed_peci_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_DESCRIPTION("ASPEED PECI driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PECI);