diff options
| -rw-r--r-- | drivers/i3c/master/i3c-master-cdns.c | 49 |
1 files changed, 44 insertions, 5 deletions
diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c index 10db0bf0655a..eed2e4fa299c 100644 --- a/drivers/i3c/master/i3c-master-cdns.c +++ b/drivers/i3c/master/i3c-master-cdns.c @@ -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, |