diff options
author | Hoan Tran <hotran@apm.com> | 2017-04-24 11:00:26 -0700 |
---|---|---|
committer | Wolfram Sang <wsa@the-dreams.de> | 2017-06-02 22:27:25 +0200 |
commit | df5da47fe722e36055b97134e6bb9df58c12495c (patch) | |
tree | 78bb9643af51503bb46678180055153be2a821b3 /drivers/i2c | |
parent | d140bd42b2ced34ce31e9e4384526ce159feabf1 (diff) | |
download | linux-df5da47fe722e36055b97134e6bb9df58c12495c.tar.bz2 |
i2c: xgene-slimpro: Add ACPI support by using PCC mailbox
This patch adds ACPI support by using PCC mailbox communication
interface.
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/i2c-xgene-slimpro.c | 174 |
1 files changed, 161 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c b/drivers/i2c/busses/i2c-xgene-slimpro.c index 4e2257850d2c..8e5c8f28bc8b 100644 --- a/drivers/i2c/busses/i2c-xgene-slimpro.c +++ b/drivers/i2c/busses/i2c-xgene-slimpro.c @@ -22,6 +22,7 @@ * using the APM X-Gene SLIMpro mailbox driver. * */ +#include <acpi/pcc.h> #include <linux/acpi.h> #include <linux/dma-mapping.h> #include <linux/i2c.h> @@ -89,6 +90,8 @@ ((addrlen << SLIMPRO_IIC_ADDRLEN_SHIFT) & SLIMPRO_IIC_ADDRLEN_MASK) | \ ((datalen << SLIMPRO_IIC_DATALEN_SHIFT) & SLIMPRO_IIC_DATALEN_MASK)) +#define SLIMPRO_MSG_TYPE(v) (((v) & 0xF0000000) >> 28) + /* * Encode for upper address for block data */ @@ -99,19 +102,47 @@ & 0x3FF00000)) #define SLIMPRO_IIC_ENCODE_ADDR(a) ((a) & 0x000FFFFF) +#define SLIMPRO_IIC_MSG_DWORD_COUNT 3 + +/* PCC related defines */ +#define PCC_SIGNATURE 0x50424300 +#define PCC_STS_CMD_COMPLETE BIT(0) +#define PCC_STS_SCI_DOORBELL BIT(1) +#define PCC_STS_ERR BIT(2) +#define PCC_STS_PLAT_NOTIFY BIT(3) +#define PCC_CMD_GENERATE_DB_INT BIT(15) + struct slimpro_i2c_dev { struct i2c_adapter adapter; struct device *dev; struct mbox_chan *mbox_chan; struct mbox_client mbox_client; + int mbox_idx; struct completion rd_complete; u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* dma_buffer[0] is used for length */ u32 *resp_msg; + phys_addr_t comm_base_addr; + void *pcc_comm_addr; }; #define to_slimpro_i2c_dev(cl) \ container_of(cl, struct slimpro_i2c_dev, mbox_client) +/* + * This function tests and clears a bitmask then returns its old value + */ +static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask) +{ + u16 ret, val; + + val = le16_to_cpu(READ_ONCE(*addr)); + ret = val & mask; + val &= ~mask; + WRITE_ONCE(*addr, cpu_to_le16(val)); + + return ret; +} + static void slimpro_i2c_rx_cb(struct mbox_client *cl, void *mssg) { struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl); @@ -129,9 +160,53 @@ static void slimpro_i2c_rx_cb(struct mbox_client *cl, void *mssg) complete(&ctx->rd_complete); } +static void slimpro_i2c_pcc_rx_cb(struct mbox_client *cl, void *msg) +{ + struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl); + struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr; + + /* Check if platform sends interrupt */ + if (!xgene_word_tst_and_clr(&generic_comm_base->status, + PCC_STS_SCI_DOORBELL)) + return; + + if (xgene_word_tst_and_clr(&generic_comm_base->status, + PCC_STS_CMD_COMPLETE)) { + msg = generic_comm_base + 1; + + /* Response message msg[1] contains the return value. */ + if (ctx->resp_msg) + *ctx->resp_msg = ((u32 *)msg)[1]; + + complete(&ctx->rd_complete); + } +} + +static void slimpro_i2c_pcc_tx_prepare(struct slimpro_i2c_dev *ctx, u32 *msg) +{ + struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr; + u32 *ptr = (void *)(generic_comm_base + 1); + u16 status; + int i; + + WRITE_ONCE(generic_comm_base->signature, + cpu_to_le32(PCC_SIGNATURE | ctx->mbox_idx)); + + WRITE_ONCE(generic_comm_base->command, + cpu_to_le16(SLIMPRO_MSG_TYPE(msg[0]) | PCC_CMD_GENERATE_DB_INT)); + + status = le16_to_cpu(READ_ONCE(generic_comm_base->status)); + status &= ~PCC_STS_CMD_COMPLETE; + WRITE_ONCE(generic_comm_base->status, cpu_to_le16(status)); + + /* Copy the message to the PCC comm space */ + for (i = 0; i < SLIMPRO_IIC_MSG_DWORD_COUNT; i++) + WRITE_ONCE(ptr[i], cpu_to_le32(msg[i])); +} + static int start_i2c_msg_xfer(struct slimpro_i2c_dev *ctx) { - if (ctx->mbox_client.tx_block) { + if (ctx->mbox_client.tx_block || !acpi_disabled) { if (!wait_for_completion_timeout(&ctx->rd_complete, msecs_to_jiffies(MAILBOX_OP_TIMEOUT))) return -ETIMEDOUT; @@ -152,6 +227,11 @@ static int slimpro_i2c_send_msg(struct slimpro_i2c_dev *ctx, ctx->resp_msg = data; + if (!acpi_disabled) { + reinit_completion(&ctx->rd_complete); + slimpro_i2c_pcc_tx_prepare(ctx, msg); + } + rc = mbox_send_message(ctx->mbox_chan, msg); if (rc < 0) goto err; @@ -159,6 +239,9 @@ static int slimpro_i2c_send_msg(struct slimpro_i2c_dev *ctx, rc = start_i2c_msg_xfer(ctx); err: + if (!acpi_disabled) + mbox_chan_txdone(ctx->mbox_chan, 0); + ctx->resp_msg = NULL; return rc; @@ -379,17 +462,73 @@ static int xgene_slimpro_i2c_probe(struct platform_device *pdev) /* Request mailbox channel */ cl->dev = &pdev->dev; - cl->rx_callback = slimpro_i2c_rx_cb; - cl->tx_block = true; init_completion(&ctx->rd_complete); cl->tx_tout = MAILBOX_OP_TIMEOUT; cl->knows_txdone = false; - ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX); - if (IS_ERR(ctx->mbox_chan)) { - dev_err(&pdev->dev, "i2c mailbox channel request failed\n"); - return PTR_ERR(ctx->mbox_chan); - } + if (acpi_disabled) { + cl->tx_block = true; + cl->rx_callback = slimpro_i2c_rx_cb; + ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX); + if (IS_ERR(ctx->mbox_chan)) { + dev_err(&pdev->dev, "i2c mailbox channel request failed\n"); + return PTR_ERR(ctx->mbox_chan); + } + } else { + struct acpi_pcct_hw_reduced *cppc_ss; + + if (device_property_read_u32(&pdev->dev, "pcc-channel", + &ctx->mbox_idx)) + ctx->mbox_idx = MAILBOX_I2C_INDEX; + + cl->tx_block = false; + cl->rx_callback = slimpro_i2c_pcc_rx_cb; + ctx->mbox_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx); + if (IS_ERR(ctx->mbox_chan)) { + dev_err(&pdev->dev, "PCC mailbox channel request failed\n"); + return PTR_ERR(ctx->mbox_chan); + } + + /* + * The PCC mailbox controller driver should + * have parsed the PCCT (global table of all + * PCC channels) and stored pointers to the + * subspace communication region in con_priv. + */ + cppc_ss = ctx->mbox_chan->con_priv; + if (!cppc_ss) { + dev_err(&pdev->dev, "PPC subspace not found\n"); + rc = -ENOENT; + goto mbox_err; + } + + if (!ctx->mbox_chan->mbox->txdone_irq) { + dev_err(&pdev->dev, "PCC IRQ not supported\n"); + rc = -ENOENT; + goto mbox_err; + } + /* + * This is the shared communication region + * for the OS and Platform to communicate over. + */ + ctx->comm_base_addr = cppc_ss->base_address; + if (ctx->comm_base_addr) { + ctx->pcc_comm_addr = memremap(ctx->comm_base_addr, + cppc_ss->length, + MEMREMAP_WB); + } else { + dev_err(&pdev->dev, "Failed to get PCC comm region\n"); + rc = -ENOENT; + goto mbox_err; + } + + if (!ctx->pcc_comm_addr) { + dev_err(&pdev->dev, + "Failed to ioremap PCC comm region\n"); + rc = -ENOMEM; + goto mbox_err; + } + } rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); if (rc) dev_warn(&pdev->dev, "Unable to set dma mask\n"); @@ -404,13 +543,19 @@ static int xgene_slimpro_i2c_probe(struct platform_device *pdev) ACPI_COMPANION_SET(&adapter->dev, ACPI_COMPANION(&pdev->dev)); i2c_set_adapdata(adapter, ctx); rc = i2c_add_adapter(adapter); - if (rc) { - mbox_free_channel(ctx->mbox_chan); - return rc; - } + if (rc) + goto mbox_err; dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n"); return 0; + +mbox_err: + if (acpi_disabled) + mbox_free_channel(ctx->mbox_chan); + else + pcc_mbox_free_channel(ctx->mbox_chan); + + return rc; } static int xgene_slimpro_i2c_remove(struct platform_device *pdev) @@ -419,7 +564,10 @@ static int xgene_slimpro_i2c_remove(struct platform_device *pdev) i2c_del_adapter(&ctx->adapter); - mbox_free_channel(ctx->mbox_chan); + if (acpi_disabled) + mbox_free_channel(ctx->mbox_chan); + else + pcc_mbox_free_channel(ctx->mbox_chan); return 0; } |