net: wwan: t7xx: Add control DMA interface

Cross Layer DMA (CLDMA) Hardware interface (HIF) enables the control
path of Host-Modem data transfers. CLDMA HIF layer provides a common
interface to the Port Layer.

CLDMA manages 8 independent RX/TX physical channels with data flow
control in HW queues. CLDMA uses ring buffers of General Packet
Descriptors (GPD) for TX/RX. GPDs can represent multiple or single
data buffers (DB).

CLDMA HIF initializes GPD rings, registers ISR handlers for CLDMA
interrupts, and initializes CLDMA HW registers.

CLDMA TX flow:
1. Port Layer write
2. Get DB address
3. Configure GPD
4. Triggering processing via HW register write

CLDMA RX flow:
1. CLDMA HW sends a RX "done" to host
2. Driver starts thread to safely read GPD
3. DB is sent to Port layer
4. Create a new buffer for GPD ring

Note: This patch does not enable compilation since it has dependencies
such as t7xx_pcie_mac_clear_int()/t7xx_pcie_mac_set_int() and
struct t7xx_pci_dev which are added by the core patch.

Signed-off-by: Haijun Liu <[email protected]>
Signed-off-by: Chandrashekar Devegowda <[email protected]>
Co-developed-by: Ricardo Martinez <[email protected]>
Signed-off-by: Ricardo Martinez <[email protected]>
Reviewed-by: Loic Poulain <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Sergey Ryazanov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Haijun Liu

drivers/net/wwan/t7xx/t7xx_cldma.c

@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021-2022, Intel Corporation.
+ *
+ * Authors:
+ *  Haijun Liu <[email protected]>
+ *  Moises Veleta <[email protected]>
+ *  Ricardo Martinez <[email protected]>
+ *
+ * Contributors:
+ *  Amir Hanania <[email protected]>
+ *  Andy Shevchenko <[email protected]>
+ *  Eliot Lee <[email protected]>
+ *  Sreehari Kancharla <[email protected]>
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/types.h>
+
+#include "t7xx_cldma.h"
+
+#define ADDR_SIZE	8
+
+void t7xx_cldma_clear_ip_busy(struct t7xx_cldma_hw *hw_info)
+{
+	u32 val;
+
+	val = ioread32(hw_info->ap_pdn_base + REG_CLDMA_IP_BUSY);
+	val |= IP_BUSY_WAKEUP;
+	iowrite32(val, hw_info->ap_pdn_base + REG_CLDMA_IP_BUSY);
+}
+
+/**
+ * t7xx_cldma_hw_restore() - Restore CLDMA HW registers.
+ * @hw_info: Pointer to struct t7xx_cldma_hw.
+ *
+ * Restore HW after resume. Writes uplink configuration for CLDMA HW.
+ */
+void t7xx_cldma_hw_restore(struct t7xx_cldma_hw *hw_info)
+{
+	u32 ul_cfg;
+
+	ul_cfg = ioread32(hw_info->ap_pdn_base + REG_CLDMA_UL_CFG);
+	ul_cfg &= ~UL_CFG_BIT_MODE_MASK;
+
+	if (hw_info->hw_mode == MODE_BIT_64)
+		ul_cfg |= UL_CFG_BIT_MODE_64;
+	else if (hw_info->hw_mode == MODE_BIT_40)
+		ul_cfg |= UL_CFG_BIT_MODE_40;
+	else if (hw_info->hw_mode == MODE_BIT_36)
+		ul_cfg |= UL_CFG_BIT_MODE_36;
+
+	iowrite32(ul_cfg, hw_info->ap_pdn_base + REG_CLDMA_UL_CFG);
+	/* Disable TX and RX invalid address check */
+	iowrite32(UL_MEM_CHECK_DIS, hw_info->ap_pdn_base + REG_CLDMA_UL_MEM);
+	iowrite32(DL_MEM_CHECK_DIS, hw_info->ap_pdn_base + REG_CLDMA_DL_MEM);
+}
+
+void t7xx_cldma_hw_start_queue(struct t7xx_cldma_hw *hw_info, unsigned int qno,
+			       enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_pdn_base + REG_CLDMA_DL_START_CMD :
+				hw_info->ap_pdn_base + REG_CLDMA_UL_START_CMD;
+	val = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	iowrite32(val, reg);
+}
+
+void t7xx_cldma_hw_start(struct t7xx_cldma_hw *hw_info)
+{
+	/* Enable the TX & RX interrupts */
+	iowrite32(TXRX_STATUS_BITMASK, hw_info->ap_pdn_base + REG_CLDMA_L2TIMCR0);
+	iowrite32(TXRX_STATUS_BITMASK, hw_info->ap_ao_base + REG_CLDMA_L2RIMCR0);
+	/* Enable the empty queue interrupt */
+	iowrite32(EMPTY_STATUS_BITMASK, hw_info->ap_pdn_base + REG_CLDMA_L2TIMCR0);
+	iowrite32(EMPTY_STATUS_BITMASK, hw_info->ap_ao_base + REG_CLDMA_L2RIMCR0);
+}
+
+void t7xx_cldma_hw_reset(void __iomem *ao_base)
+{
+	u32 val;
+
+	val = ioread32(ao_base + REG_INFRA_RST2_SET);
+	val |= RST2_PMIC_SW_RST_SET;
+	iowrite32(val, ao_base + REG_INFRA_RST2_SET);
+	val = ioread32(ao_base + REG_INFRA_RST4_SET);
+	val |= RST4_CLDMA1_SW_RST_SET;
+	iowrite32(val, ao_base + REG_INFRA_RST4_SET);
+	udelay(1);
+
+	val = ioread32(ao_base + REG_INFRA_RST4_CLR);
+	val |= RST4_CLDMA1_SW_RST_CLR;
+	iowrite32(val, ao_base + REG_INFRA_RST4_CLR);
+	val = ioread32(ao_base + REG_INFRA_RST2_CLR);
+	val |= RST2_PMIC_SW_RST_CLR;
+	iowrite32(val, ao_base + REG_INFRA_RST2_CLR);
+}
+
+bool t7xx_cldma_tx_addr_is_set(struct t7xx_cldma_hw *hw_info, unsigned int qno)
+{
+	u32 offset = REG_CLDMA_UL_START_ADDRL_0 + qno * ADDR_SIZE;
+
+	return ioread64(hw_info->ap_pdn_base + offset);
+}
+
+void t7xx_cldma_hw_set_start_addr(struct t7xx_cldma_hw *hw_info, unsigned int qno, u64 address,
+				  enum mtk_txrx tx_rx)
+{
+	u32 offset = qno * ADDR_SIZE;
+	void __iomem *reg;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_DL_START_ADDRL_0 :
+				hw_info->ap_pdn_base + REG_CLDMA_UL_START_ADDRL_0;
+	iowrite64(address, reg + offset);
+}
+
+void t7xx_cldma_hw_resume_queue(struct t7xx_cldma_hw *hw_info, unsigned int qno,
+				enum mtk_txrx tx_rx)
+{
+	void __iomem *base = hw_info->ap_pdn_base;
+
+	if (tx_rx == MTK_RX)
+		iowrite32(BIT(qno), base + REG_CLDMA_DL_RESUME_CMD);
+	else
+		iowrite32(BIT(qno), base + REG_CLDMA_UL_RESUME_CMD);
+}
+
+unsigned int t7xx_cldma_hw_queue_status(struct t7xx_cldma_hw *hw_info, unsigned int qno,
+					enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 mask, val;
+
+	mask = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_DL_STATUS :
+				hw_info->ap_pdn_base + REG_CLDMA_UL_STATUS;
+	val = ioread32(reg);
+
+	return val & mask;
+}
+
+void t7xx_cldma_hw_tx_done(struct t7xx_cldma_hw *hw_info, unsigned int bitmask)
+{
+	unsigned int ch_id;
+
+	ch_id = ioread32(hw_info->ap_pdn_base + REG_CLDMA_L2TISAR0);
+	ch_id &= bitmask;
+	/* Clear the ch IDs in the TX interrupt status register */
+	iowrite32(ch_id, hw_info->ap_pdn_base + REG_CLDMA_L2TISAR0);
+	ioread32(hw_info->ap_pdn_base + REG_CLDMA_L2TISAR0);
+}
+
+void t7xx_cldma_hw_rx_done(struct t7xx_cldma_hw *hw_info, unsigned int bitmask)
+{
+	unsigned int ch_id;
+
+	ch_id = ioread32(hw_info->ap_pdn_base + REG_CLDMA_L2RISAR0);
+	ch_id &= bitmask;
+	/* Clear the ch IDs in the RX interrupt status register */
+	iowrite32(ch_id, hw_info->ap_pdn_base + REG_CLDMA_L2RISAR0);
+	ioread32(hw_info->ap_pdn_base + REG_CLDMA_L2RISAR0);
+}
+
+unsigned int t7xx_cldma_hw_int_status(struct t7xx_cldma_hw *hw_info, unsigned int bitmask,
+				      enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_pdn_base + REG_CLDMA_L2RISAR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TISAR0;
+	val = ioread32(reg);
+	return val & bitmask;
+}
+
+void t7xx_cldma_hw_irq_dis_txrx(struct t7xx_cldma_hw *hw_info, unsigned int qno,
+				enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_L2RIMSR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TIMSR0;
+	val = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	iowrite32(val, reg);
+}
+
+void t7xx_cldma_hw_irq_dis_eq(struct t7xx_cldma_hw *hw_info, unsigned int qno, enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_L2RIMSR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TIMSR0;
+	val = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	iowrite32(val << EQ_STA_BIT_OFFSET, reg);
+}
+
+void t7xx_cldma_hw_irq_en_txrx(struct t7xx_cldma_hw *hw_info, unsigned int qno,
+			       enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_L2RIMCR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TIMCR0;
+	val = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	iowrite32(val, reg);
+}
+
+void t7xx_cldma_hw_irq_en_eq(struct t7xx_cldma_hw *hw_info, unsigned int qno, enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+	u32 val;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_L2RIMCR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TIMCR0;
+	val = qno == CLDMA_ALL_Q ? CLDMA_ALL_Q : BIT(qno);
+	iowrite32(val << EQ_STA_BIT_OFFSET, reg);
+}
+
+/**
+ * t7xx_cldma_hw_init() - Initialize CLDMA HW.
+ * @hw_info: Pointer to struct t7xx_cldma_hw.
+ *
+ * Write uplink and downlink configuration to CLDMA HW.
+ */
+void t7xx_cldma_hw_init(struct t7xx_cldma_hw *hw_info)
+{
+	u32 ul_cfg, dl_cfg;
+
+	ul_cfg = ioread32(hw_info->ap_pdn_base + REG_CLDMA_UL_CFG);
+	dl_cfg = ioread32(hw_info->ap_ao_base + REG_CLDMA_DL_CFG);
+	/* Configure the DRAM address mode */
+	ul_cfg &= ~UL_CFG_BIT_MODE_MASK;
+	dl_cfg &= ~DL_CFG_BIT_MODE_MASK;
+
+	if (hw_info->hw_mode == MODE_BIT_64) {
+		ul_cfg |= UL_CFG_BIT_MODE_64;
+		dl_cfg |= DL_CFG_BIT_MODE_64;
+	} else if (hw_info->hw_mode == MODE_BIT_40) {
+		ul_cfg |= UL_CFG_BIT_MODE_40;
+		dl_cfg |= DL_CFG_BIT_MODE_40;
+	} else if (hw_info->hw_mode == MODE_BIT_36) {
+		ul_cfg |= UL_CFG_BIT_MODE_36;
+		dl_cfg |= DL_CFG_BIT_MODE_36;
+	}
+
+	iowrite32(ul_cfg, hw_info->ap_pdn_base + REG_CLDMA_UL_CFG);
+	dl_cfg |= DL_CFG_UP_HW_LAST;
+	iowrite32(dl_cfg, hw_info->ap_ao_base + REG_CLDMA_DL_CFG);
+	iowrite32(0, hw_info->ap_ao_base + REG_CLDMA_INT_MASK);
+	iowrite32(BUSY_MASK_MD, hw_info->ap_ao_base + REG_CLDMA_BUSY_MASK);
+	iowrite32(UL_MEM_CHECK_DIS, hw_info->ap_pdn_base + REG_CLDMA_UL_MEM);
+	iowrite32(DL_MEM_CHECK_DIS, hw_info->ap_pdn_base + REG_CLDMA_DL_MEM);
+}
+
+void t7xx_cldma_hw_stop_all_qs(struct t7xx_cldma_hw *hw_info, enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_pdn_base + REG_CLDMA_DL_STOP_CMD :
+				hw_info->ap_pdn_base + REG_CLDMA_UL_STOP_CMD;
+	iowrite32(CLDMA_ALL_Q, reg);
+}
+
+void t7xx_cldma_hw_stop(struct t7xx_cldma_hw *hw_info, enum mtk_txrx tx_rx)
+{
+	void __iomem *reg;
+
+	reg = tx_rx == MTK_RX ? hw_info->ap_ao_base + REG_CLDMA_L2RIMSR0 :
+				hw_info->ap_pdn_base + REG_CLDMA_L2TIMSR0;
+	iowrite32(TXRX_STATUS_BITMASK, reg);
+	iowrite32(EMPTY_STATUS_BITMASK, reg);
+}