i3c: master: cdns: add data hold delay support (dbd66543) · Commits · 戴 / test

drivers/i3c/master/i3c-master-cdns.c

+44 −5

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@
		#include <linux/slab.h>
		#include <linux/spinlock.h>
		#include <linux/workqueue.h>
		#include <linux/of_device.h>

		#define DEV_ID 0x0
		#define DEV_ID_I3C_MASTER 0x5034
		@@ -60,6 +61,7 @@
		#define CTRL_HALT_EN BIT(30)
		#define CTRL_MCS BIT(29)
		#define CTRL_MCS_EN BIT(28)
		#define CTRL_THD_DELAY(x) (((x) << 24) & GENMASK(25, 24))
		#define CTRL_HJ_DISEC BIT(8)
		#define CTRL_MST_ACK BIT(7)
		#define CTRL_HJ_ACK BIT(6)
		@@ -70,6 +72,7 @@
		#define CTRL_MIXED_FAST_BUS_MODE 2
		#define CTRL_MIXED_SLOW_BUS_MODE 3
		#define CTRL_BUS_MODE_MASK GENMASK(1, 0)
		#define THD_DELAY_MAX 3

		#define PRESCL_CTRL0 0x14
		#define PRESCL_CTRL0_I2C(x) ((x) << 16)
		@@ -388,6 +391,10 @@ struct cdns_i3c_xfer {
		struct cdns_i3c_cmd cmds[0];
		};

		struct cdns_i3c_data {
		u8 thd_delay_ns;
		};

		struct cdns_i3c_master {
		struct work_struct hj_work;
		struct i3c_master_controller base;
		@@ -408,6 +415,7 @@ struct cdns_i3c_master {
		struct clk *pclk;
		struct cdns_i3c_master_caps caps;
		unsigned long i3c_scl_lim;
		const struct cdns_i3c_data *devdata;
		};

		static inline struct cdns_i3c_master *
		@@ -1181,6 +1189,20 @@ static int cdns_i3c_master_do_daa(struct i3c_master_controller *m)
		return 0;
		}

		static u8 cdns_i3c_master_calculate_thd_delay(struct cdns_i3c_master *master)
		{
		unsigned long sysclk_rate = clk_get_rate(master->sysclk);
		u8 thd_delay = DIV_ROUND_UP(master->devdata->thd_delay_ns,
		(NSEC_PER_SEC / sysclk_rate));

		/* Every value greater than 3 is not valid. */
		if (thd_delay > THD_DELAY_MAX)
		thd_delay = THD_DELAY_MAX;

		/* CTLR_THD_DEL value is encoded. */
		return (THD_DELAY_MAX - thd_delay);
		}

		static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
		{
		struct cdns_i3c_master *master = to_cdns_i3c_master(m);
		@@ -1264,6 +1286,15 @@ static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
		* We will issue ENTDAA afterwards from the threaded IRQ handler.
		*/
		ctrl \|= CTRL_HJ_ACK \| CTRL_HJ_DISEC \| CTRL_HALT_EN \| CTRL_MCS_EN;

		/*
		* Configure data hold delay based on device-specific data.
		*
		* MIPI I3C Specification 1.0 defines non-zero minimal tHD_PP timing on
		* master output. This setting allows to meet this timing on master's
		* SoC outputs, regardless of PCB balancing.
		*/
		ctrl \|= CTRL_THD_DELAY(cdns_i3c_master_calculate_thd_delay(master));
		writel(ctrl, master->regs + CTRL);

		cdns_i3c_master_enable(master);
		@@ -1521,6 +1552,15 @@ static void cdns_i3c_master_hj(struct work_struct *work)
		i3c_master_do_daa(&master->base);
		}

		static struct cdns_i3c_data cdns_i3c_devdata = {
		.thd_delay_ns = 10,
		};

		static const struct of_device_id cdns_i3c_master_of_ids[] = {
		{ .compatible = "cdns,i3c-master", .data = &cdns_i3c_devdata },
		{ /* sentinel */ },
		};

		static int cdns_i3c_master_probe(struct platform_device *pdev)
		{
		struct cdns_i3c_master *master;
		@@ -1532,6 +1572,10 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
		if (!master)
		return -ENOMEM;

		master->devdata = of_device_get_match_data(&pdev->dev);
		if (!master->devdata)
		return -EINVAL;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		master->regs = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(master->regs))
		@@ -1631,11 +1675,6 @@ static int cdns_i3c_master_remove(struct platform_device *pdev)
		return 0;
		}

		static const struct of_device_id cdns_i3c_master_of_ids[] = {
		{ .compatible = "cdns,i3c-master" },
		{ /* sentinel */ },
		};

		static struct platform_driver cdns_i3c_master = {
		.probe = cdns_i3c_master_probe,
		.remove = cdns_i3c_master_remove,

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