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authorJeremy Kerr <jk@codeconstruct.com.au>2023-03-30 15:50:34 +0800
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2023-04-28 08:20:07 +0200
commite389b1d72a6241b326071dd75e1b33f9e8818cd1 (patch)
treeb45acb77078b5337028c7131fbf04d4eecdc4358 /drivers/i3c
parente2d43101f61d6e79510d1cd9e7052b4745b8d809 (diff)
i3c: dw: Add support for in-band interrupts
This change adds support for receiving and dequeueing i3c IBIs. By setting struct dw_i3c_master->ibi_capable before probe, a platform implementation can select the IBI-enabled version of the i3c_master_ops, enabling the global IBI infrastrcture for that controller. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/79daeefd7ccb7c935d0c159149df21a6c9a73ffa.1680161823.git.jk@codeconstruct.com.au Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/i3c')
-rw-r--r--drivers/i3c/master/dw-i3c-master.c281
-rw-r--r--drivers/i3c/master/dw-i3c-master.h11
2 files changed, 289 insertions, 3 deletions
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 0552a82c694f..05f896d6e2cb 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -76,7 +76,22 @@
#define RX_TX_DATA_PORT 0x14
#define IBI_QUEUE_STATUS 0x18
+#define IBI_QUEUE_STATUS_IBI_ID(x) (((x) & GENMASK(15, 8)) >> 8)
+#define IBI_QUEUE_STATUS_DATA_LEN(x) ((x) & GENMASK(7, 0))
+#define IBI_QUEUE_IBI_ADDR(x) (IBI_QUEUE_STATUS_IBI_ID(x) >> 1)
+#define IBI_QUEUE_IBI_RNW(x) (IBI_QUEUE_STATUS_IBI_ID(x) & BIT(0))
+#define IBI_TYPE_MR(x) \
+ ((IBI_QUEUE_IBI_ADDR(x) != I3C_HOT_JOIN_ADDR) && !IBI_QUEUE_IBI_RNW(x))
+#define IBI_TYPE_HJ(x) \
+ ((IBI_QUEUE_IBI_ADDR(x) == I3C_HOT_JOIN_ADDR) && !IBI_QUEUE_IBI_RNW(x))
+#define IBI_TYPE_SIRQ(x) \
+ ((IBI_QUEUE_IBI_ADDR(x) != I3C_HOT_JOIN_ADDR) && IBI_QUEUE_IBI_RNW(x))
+
#define QUEUE_THLD_CTRL 0x1c
+#define QUEUE_THLD_CTRL_IBI_STAT_MASK GENMASK(31, 24)
+#define QUEUE_THLD_CTRL_IBI_STAT(x) (((x) - 1) << 24)
+#define QUEUE_THLD_CTRL_IBI_DATA_MASK GENMASK(20, 16)
+#define QUEUE_THLD_CTRL_IBI_DATA(x) ((x) << 16)
#define QUEUE_THLD_CTRL_RESP_BUF_MASK GENMASK(15, 8)
#define QUEUE_THLD_CTRL_RESP_BUF(x) (((x) - 1) << 8)
@@ -186,6 +201,8 @@
#define EXTENDED_CAPABILITY 0xe8
#define SLAVE_CONFIG 0xec
+#define DEV_ADDR_TABLE_IBI_MDB BIT(12)
+#define DEV_ADDR_TABLE_SIR_REJECT BIT(13)
#define DEV_ADDR_TABLE_LEGACY_I2C_DEV BIT(31)
#define DEV_ADDR_TABLE_DYNAMIC_ADDR(x) (((x) << 16) & GENMASK(23, 16))
#define DEV_ADDR_TABLE_STATIC_ADDR(x) ((x) & GENMASK(6, 0))
@@ -221,6 +238,7 @@ struct dw_i3c_xfer {
struct dw_i3c_i2c_dev_data {
u8 index;
+ struct i3c_generic_ibi_pool *ibi_pool;
};
static u8 even_parity(u8 p)
@@ -336,6 +354,12 @@ static void dw_i3c_master_read_rx_fifo(struct dw_i3c_master *master,
return dw_i3c_master_read_fifo(master, RX_TX_DATA_PORT, bytes, nbytes);
}
+static void dw_i3c_master_read_ibi_fifo(struct dw_i3c_master *master,
+ u8 *bytes, int nbytes)
+{
+ return dw_i3c_master_read_fifo(master, IBI_QUEUE_STATUS, bytes, nbytes);
+}
+
static struct dw_i3c_xfer *
dw_i3c_master_alloc_xfer(struct dw_i3c_master *master, unsigned int ncmds)
{
@@ -605,7 +629,11 @@ static int dw_i3c_master_bus_init(struct i3c_master_controller *m)
}
thld_ctrl = readl(master->regs + QUEUE_THLD_CTRL);
- thld_ctrl &= ~QUEUE_THLD_CTRL_RESP_BUF_MASK;
+ thld_ctrl &= ~(QUEUE_THLD_CTRL_RESP_BUF_MASK |
+ QUEUE_THLD_CTRL_IBI_STAT_MASK |
+ QUEUE_THLD_CTRL_IBI_STAT_MASK);
+ thld_ctrl |= QUEUE_THLD_CTRL_IBI_STAT(1) |
+ QUEUE_THLD_CTRL_IBI_DATA(31);
writel(thld_ctrl, master->regs + QUEUE_THLD_CTRL);
thld_ctrl = readl(master->regs + DATA_BUFFER_THLD_CTRL);
@@ -1074,6 +1102,226 @@ static void dw_i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
kfree(data);
}
+static int dw_i3c_master_request_ibi(struct i3c_dev_desc *dev,
+ const struct i3c_ibi_setup *req)
+{
+ struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
+ struct i3c_master_controller *m = i3c_dev_get_master(dev);
+ struct dw_i3c_master *master = to_dw_i3c_master(m);
+ unsigned long flags;
+
+ data->ibi_pool = i3c_generic_ibi_alloc_pool(dev, req);
+ if (IS_ERR(data->ibi_pool))
+ return PTR_ERR(data->ibi_pool);
+
+ spin_lock_irqsave(&master->devs_lock, flags);
+ master->devs[data->index].ibi_dev = dev;
+ spin_unlock_irqrestore(&master->devs_lock, flags);
+
+ return 0;
+}
+
+static void dw_i3c_master_free_ibi(struct i3c_dev_desc *dev)
+{
+ struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
+ struct i3c_master_controller *m = i3c_dev_get_master(dev);
+ struct dw_i3c_master *master = to_dw_i3c_master(m);
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->devs_lock, flags);
+ master->devs[data->index].ibi_dev = NULL;
+ spin_unlock_irqrestore(&master->devs_lock, flags);
+
+ i3c_generic_ibi_free_pool(data->ibi_pool);
+ data->ibi_pool = NULL;
+}
+
+static void dw_i3c_master_set_sir_enabled(struct dw_i3c_master *master,
+ struct i3c_dev_desc *dev,
+ u8 idx, bool enable)
+{
+ unsigned long flags;
+ u32 dat_entry, reg;
+ bool global;
+
+ dat_entry = DEV_ADDR_TABLE_LOC(master->datstartaddr, idx);
+
+ spin_lock_irqsave(&master->devs_lock, flags);
+ reg = readl(master->regs + dat_entry);
+ if (enable) {
+ reg &= ~DEV_ADDR_TABLE_SIR_REJECT;
+ if (dev->info.bcr & I3C_BCR_IBI_PAYLOAD)
+ reg |= DEV_ADDR_TABLE_IBI_MDB;
+ } else {
+ reg |= DEV_ADDR_TABLE_SIR_REJECT;
+ }
+ writel(reg, master->regs + dat_entry);
+
+ reg = readl(master->regs + IBI_SIR_REQ_REJECT);
+ if (enable) {
+ global = reg == 0xffffffff;
+ reg &= ~BIT(idx);
+ } else {
+ global = reg == 0;
+ reg |= BIT(idx);
+ }
+ writel(reg, master->regs + IBI_SIR_REQ_REJECT);
+
+ if (global) {
+ reg = readl(master->regs + INTR_STATUS_EN);
+ reg &= ~INTR_IBI_THLD_STAT;
+ if (enable)
+ reg |= INTR_IBI_THLD_STAT;
+ writel(reg, master->regs + INTR_STATUS_EN);
+
+ reg = readl(master->regs + INTR_SIGNAL_EN);
+ reg &= ~INTR_IBI_THLD_STAT;
+ if (enable)
+ reg |= INTR_IBI_THLD_STAT;
+ writel(reg, master->regs + INTR_SIGNAL_EN);
+ }
+
+ spin_unlock_irqrestore(&master->devs_lock, flags);
+}
+
+static int dw_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
+{
+ struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
+ struct i3c_master_controller *m = i3c_dev_get_master(dev);
+ struct dw_i3c_master *master = to_dw_i3c_master(m);
+ int rc;
+
+ dw_i3c_master_set_sir_enabled(master, dev, data->index, true);
+
+ rc = i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
+
+ if (rc)
+ dw_i3c_master_set_sir_enabled(master, dev, data->index, false);
+
+ return rc;
+}
+
+static int dw_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
+{
+ struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
+ struct i3c_master_controller *m = i3c_dev_get_master(dev);
+ struct dw_i3c_master *master = to_dw_i3c_master(m);
+ int rc;
+
+ rc = i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
+ if (rc)
+ return rc;
+
+ dw_i3c_master_set_sir_enabled(master, dev, data->index, false);
+
+ return 0;
+}
+
+static void dw_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
+ struct i3c_ibi_slot *slot)
+{
+ struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
+
+ i3c_generic_ibi_recycle_slot(data->ibi_pool, slot);
+}
+
+static void dw_i3c_master_drain_ibi_queue(struct dw_i3c_master *master,
+ int len)
+{
+ int i;
+
+ for (i = 0; i < DIV_ROUND_UP(len, 4); i++)
+ readl(master->regs + IBI_QUEUE_STATUS);
+}
+
+static void dw_i3c_master_handle_ibi_sir(struct dw_i3c_master *master,
+ u32 status)
+{
+ struct dw_i3c_i2c_dev_data *data;
+ struct i3c_ibi_slot *slot;
+ struct i3c_dev_desc *dev;
+ unsigned long flags;
+ u8 addr, len;
+ int idx;
+
+ addr = IBI_QUEUE_IBI_ADDR(status);
+ len = IBI_QUEUE_STATUS_DATA_LEN(status);
+
+ spin_lock_irqsave(&master->devs_lock, flags);
+ idx = dw_i3c_master_get_addr_pos(master, addr);
+ if (idx < 0) {
+ dev_dbg_ratelimited(&master->base.dev,
+ "IBI from unknown addr 0x%x\n", addr);
+ goto err_drain;
+ }
+
+ dev = master->devs[idx].ibi_dev;
+ if (!dev || !dev->ibi) {
+ dev_dbg_ratelimited(&master->base.dev,
+ "IBI from non-requested dev idx %d\n", idx);
+ goto err_drain;
+ }
+
+ data = i3c_dev_get_master_data(dev);
+ slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
+ if (!slot) {
+ dev_dbg_ratelimited(&master->base.dev,
+ "No IBI slots available\n");
+ goto err_drain;
+ }
+
+ if (dev->ibi->max_payload_len < len) {
+ dev_dbg_ratelimited(&master->base.dev,
+ "IBI payload len %d greater than max %d\n",
+ len, dev->ibi->max_payload_len);
+ goto err_drain;
+ }
+
+ if (len) {
+ dw_i3c_master_read_ibi_fifo(master, slot->data, len);
+ slot->len = len;
+ }
+ i3c_master_queue_ibi(dev, slot);
+
+ spin_unlock_irqrestore(&master->devs_lock, flags);
+
+ return;
+
+err_drain:
+ dw_i3c_master_drain_ibi_queue(master, len);
+
+ spin_unlock_irqrestore(&master->devs_lock, flags);
+}
+
+/* "ibis": referring to In-Band Interrupts, and not
+ * https://en.wikipedia.org/wiki/Australian_white_ibis. The latter should
+ * not be handled.
+ */
+static void dw_i3c_master_irq_handle_ibis(struct dw_i3c_master *master)
+{
+ unsigned int i, len, n_ibis;
+ u32 reg;
+
+ reg = readl(master->regs + QUEUE_STATUS_LEVEL);
+ n_ibis = QUEUE_STATUS_IBI_STATUS_CNT(reg);
+ if (!n_ibis)
+ return;
+
+ for (i = 0; i < n_ibis; i++) {
+ reg = readl(master->regs + IBI_QUEUE_STATUS);
+
+ if (IBI_TYPE_SIRQ(reg)) {
+ dw_i3c_master_handle_ibi_sir(master, reg);
+ } else {
+ len = IBI_QUEUE_STATUS_DATA_LEN(reg);
+ dev_info(&master->base.dev,
+ "unsupported IBI type 0x%lx len %d\n",
+ IBI_QUEUE_STATUS_IBI_ID(reg), len);
+ dw_i3c_master_drain_ibi_queue(master, len);
+ }
+ }
+}
+
static irqreturn_t dw_i3c_master_irq_handler(int irq, void *dev_id)
{
struct dw_i3c_master *master = dev_id;
@@ -1092,6 +1340,9 @@ static irqreturn_t dw_i3c_master_irq_handler(int irq, void *dev_id)
writel(INTR_TRANSFER_ERR_STAT, master->regs + INTR_STATUS);
spin_unlock(&master->xferqueue.lock);
+ if (status & INTR_IBI_THLD_STAT)
+ dw_i3c_master_irq_handle_ibis(master);
+
return IRQ_HANDLED;
}
@@ -1110,6 +1361,26 @@ static const struct i3c_master_controller_ops dw_mipi_i3c_ops = {
.i2c_xfers = dw_i3c_master_i2c_xfers,
};
+static const struct i3c_master_controller_ops dw_mipi_i3c_ibi_ops = {
+ .bus_init = dw_i3c_master_bus_init,
+ .bus_cleanup = dw_i3c_master_bus_cleanup,
+ .attach_i3c_dev = dw_i3c_master_attach_i3c_dev,
+ .reattach_i3c_dev = dw_i3c_master_reattach_i3c_dev,
+ .detach_i3c_dev = dw_i3c_master_detach_i3c_dev,
+ .do_daa = dw_i3c_master_daa,
+ .supports_ccc_cmd = dw_i3c_master_supports_ccc_cmd,
+ .send_ccc_cmd = dw_i3c_master_send_ccc_cmd,
+ .priv_xfers = dw_i3c_master_priv_xfers,
+ .attach_i2c_dev = dw_i3c_master_attach_i2c_dev,
+ .detach_i2c_dev = dw_i3c_master_detach_i2c_dev,
+ .i2c_xfers = dw_i3c_master_i2c_xfers,
+ .request_ibi = dw_i3c_master_request_ibi,
+ .free_ibi = dw_i3c_master_free_ibi,
+ .enable_ibi = dw_i3c_master_enable_ibi,
+ .disable_ibi = dw_i3c_master_disable_ibi,
+ .recycle_ibi_slot = dw_i3c_master_recycle_ibi_slot,
+};
+
/* default platform ops implementations */
static int dw_i3c_platform_init_nop(struct dw_i3c_master *i3c)
{
@@ -1123,6 +1394,7 @@ static const struct dw_i3c_platform_ops dw_i3c_platform_ops_default = {
int dw_i3c_common_probe(struct dw_i3c_master *master,
struct platform_device *pdev)
{
+ const struct i3c_master_controller_ops *ops;
int ret, irq;
if (!master->platform_ops)
@@ -1172,8 +1444,11 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
master->maxdevs = ret >> 16;
master->free_pos = GENMASK(master->maxdevs - 1, 0);
- ret = i3c_master_register(&master->base, &pdev->dev,
- &dw_mipi_i3c_ops, false);
+ ops = &dw_mipi_i3c_ops;
+ if (master->ibi_capable)
+ ops = &dw_mipi_i3c_ibi_ops;
+
+ ret = i3c_master_register(&master->base, &pdev->dev, ops, false);
if (ret)
goto err_assert_rst;
diff --git a/drivers/i3c/master/dw-i3c-master.h b/drivers/i3c/master/dw-i3c-master.h
index 5fb620727639..a5425fa6b7d4 100644
--- a/drivers/i3c/master/dw-i3c-master.h
+++ b/drivers/i3c/master/dw-i3c-master.h
@@ -19,6 +19,7 @@ struct dw_i3c_master_caps {
struct dw_i3c_dat_entry {
u8 addr;
+ struct i3c_dev_desc *ibi_dev;
};
struct dw_i3c_master {
@@ -37,12 +38,22 @@ struct dw_i3c_master {
struct clk *core_clk;
char version[5];
char type[5];
+ bool ibi_capable;
/*
* Per-device hardware data, used to manage the device address table
* (DAT)
+ *
+ * Locking: the devs array may be referenced in IRQ context while
+ * processing an IBI. However, IBIs (for a specific device, which
+ * implies a specific DAT entry) can only happen while interrupts are
+ * requested for that device, which is serialised against other
+ * insertions/removals from the array by the global i3c infrastructure.
+ * So, devs_lock protects against concurrent updates to devs->ibi_dev
+ * between request_ibi/free_ibi and the IBI irq event.
*/
struct dw_i3c_dat_entry devs[DW_I3C_MAX_DEVS];
+ spinlock_t devs_lock;
/* platform-specific data */
const struct dw_i3c_platform_ops *platform_ops;