lkml.org 
[lkml]   [2019]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCHv6 01/28] PCI: mobiveil: Unify register accessors
Date
It is confusing to have two sets of functions to read/write
registers, some with csr_readl()/csr_writel(), while others with
read_paged_register()/write_paged_register().

In the register space the lower 3KB of 4KB PCIe configure space can be
accessed directly and higher 1KB through a simple paging mechanism.

Unify the register accessors in csr_readl() and csr_writel() by
comparing the register offset with page access boundary 3KB in the
accessor internal so that the paging mechanism is hidden behind
the csr_read()/write() common function calls.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Reviewed-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
---
V6:
- No change.

drivers/pci/controller/pcie-mobiveil.c | 179 ++++++++++++++++++++++----------
1 files changed, 124 insertions(+), 55 deletions(-)

diff --git a/drivers/pci/controller/pcie-mobiveil.c b/drivers/pci/controller/pcie-mobiveil.c
index 77052a0..d55c7e7 100644
--- a/drivers/pci/controller/pcie-mobiveil.c
+++ b/drivers/pci/controller/pcie-mobiveil.c
@@ -47,7 +47,6 @@
#define PAGE_SEL_SHIFT 13
#define PAGE_SEL_MASK 0x3f
#define PAGE_LO_MASK 0x3ff
-#define PAGE_SEL_EN 0xc00
#define PAGE_SEL_OFFSET_SHIFT 10

#define PAB_AXI_PIO_CTRL 0x0840
@@ -117,6 +116,12 @@
#define LINK_WAIT_MIN 90000
#define LINK_WAIT_MAX 100000

+#define PAGED_ADDR_BNDRY 0xc00
+#define OFFSET_TO_PAGE_ADDR(off) \
+ ((off & PAGE_LO_MASK) | PAGED_ADDR_BNDRY)
+#define OFFSET_TO_PAGE_IDX(off) \
+ ((off >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK)
+
struct mobiveil_msi { /* MSI information */
struct mutex lock; /* protect bitmap variable */
struct irq_domain *msi_domain;
@@ -145,15 +150,119 @@ struct mobiveil_pcie {
struct mobiveil_msi msi;
};

-static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
- const u32 reg)
+/*
+ * mobiveil_pcie_sel_page - routine to access paged register
+ *
+ * Registers whose address greater than PAGED_ADDR_BNDRY (0xc00) are paged,
+ * for this scheme to work extracted higher 6 bits of the offset will be
+ * written to pg_sel field of PAB_CTRL register and rest of the lower 10
+ * bits enabled with PAGED_ADDR_BNDRY are used as offset of the register.
+ */
+static void mobiveil_pcie_sel_page(struct mobiveil_pcie *pcie, u8 pg_idx)
{
- writel_relaxed(value, pcie->csr_axi_slave_base + reg);
+ u32 val;
+
+ val = readl(pcie->csr_axi_slave_base + PAB_CTRL);
+ val &= ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT);
+ val |= (pg_idx & PAGE_SEL_MASK) << PAGE_SEL_SHIFT;
+
+ writel(val, pcie->csr_axi_slave_base + PAB_CTRL);
}

-static inline u32 csr_readl(struct mobiveil_pcie *pcie, const u32 reg)
+static void *mobiveil_pcie_comp_addr(struct mobiveil_pcie *pcie, u32 off)
{
- return readl_relaxed(pcie->csr_axi_slave_base + reg);
+ if (off < PAGED_ADDR_BNDRY) {
+ /* For directly accessed registers, clear the pg_sel field */
+ mobiveil_pcie_sel_page(pcie, 0);
+ return pcie->csr_axi_slave_base + off;
+ }
+
+ mobiveil_pcie_sel_page(pcie, OFFSET_TO_PAGE_IDX(off));
+ return pcie->csr_axi_slave_base + OFFSET_TO_PAGE_ADDR(off);
+}
+
+static int mobiveil_pcie_read(void __iomem *addr, int size, u32 *val)
+{
+ if ((uintptr_t)addr & (size - 1)) {
+ *val = 0;
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ }
+
+ switch (size) {
+ case 4:
+ *val = readl(addr);
+ break;
+ case 2:
+ *val = readw(addr);
+ break;
+ case 1:
+ *val = readb(addr);
+ break;
+ default:
+ *val = 0;
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int mobiveil_pcie_write(void __iomem *addr, int size, u32 val)
+{
+ if ((uintptr_t)addr & (size - 1))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ switch (size) {
+ case 4:
+ writel(val, addr);
+ break;
+ case 2:
+ writew(val, addr);
+ break;
+ case 1:
+ writeb(val, addr);
+ break;
+ default:
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static u32 csr_read(struct mobiveil_pcie *pcie, u32 off, size_t size)
+{
+ void *addr;
+ u32 val;
+ int ret;
+
+ addr = mobiveil_pcie_comp_addr(pcie, off);
+
+ ret = mobiveil_pcie_read(addr, size, &val);
+ if (ret)
+ dev_err(&pcie->pdev->dev, "read CSR address failed\n");
+
+ return val;
+}
+
+static void csr_write(struct mobiveil_pcie *pcie, u32 val, u32 off, size_t size)
+{
+ void *addr;
+ int ret;
+
+ addr = mobiveil_pcie_comp_addr(pcie, off);
+
+ ret = mobiveil_pcie_write(addr, size, val);
+ if (ret)
+ dev_err(&pcie->pdev->dev, "write CSR address failed\n");
+}
+
+static u32 csr_readl(struct mobiveil_pcie *pcie, u32 off)
+{
+ return csr_read(pcie, off, 0x4);
+}
+
+static void csr_writel(struct mobiveil_pcie *pcie, u32 val, u32 off)
+{
+ csr_write(pcie, val, off, 0x4);
}

static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
@@ -342,45 +451,6 @@ static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
return 0;
}

-/*
- * select_paged_register - routine to access paged register of root complex
- *
- * registers of RC are paged, for this scheme to work
- * extracted higher 6 bits of the offset will be written to pg_sel
- * field of PAB_CTRL register and rest of the lower 10 bits enabled with
- * PAGE_SEL_EN are used as offset of the register.
- */
-static void select_paged_register(struct mobiveil_pcie *pcie, u32 offset)
-{
- int pab_ctrl_dw, pg_sel;
-
- /* clear pg_sel field */
- pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
- pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
-
- /* set pg_sel field */
- pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
- pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
- csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
-}
-
-static void write_paged_register(struct mobiveil_pcie *pcie,
- u32 val, u32 offset)
-{
- u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
-
- select_paged_register(pcie, offset);
- csr_writel(pcie, val, off);
-}
-
-static u32 read_paged_register(struct mobiveil_pcie *pcie, u32 offset)
-{
- u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
-
- select_paged_register(pcie, offset);
- return csr_readl(pcie, off);
-}
-
static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
int pci_addr, u32 type, u64 size)
{
@@ -397,19 +467,19 @@ static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
csr_writel(pcie,
pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
- amap_ctrl_dw = read_paged_register(pcie, PAB_PEX_AMAP_CTRL(win_num));
+ amap_ctrl_dw = csr_readl(pcie, PAB_PEX_AMAP_CTRL(win_num));
amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));

- write_paged_register(pcie, amap_ctrl_dw | lower_32_bits(size64),
- PAB_PEX_AMAP_CTRL(win_num));
+ csr_writel(pcie, amap_ctrl_dw | lower_32_bits(size64),
+ PAB_PEX_AMAP_CTRL(win_num));

- write_paged_register(pcie, upper_32_bits(size64),
- PAB_EXT_PEX_AMAP_SIZEN(win_num));
+ csr_writel(pcie, upper_32_bits(size64),
+ PAB_EXT_PEX_AMAP_SIZEN(win_num));

- write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
- write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
- write_paged_register(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
+ csr_writel(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
+ csr_writel(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
+ csr_writel(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
}

/*
@@ -437,8 +507,7 @@ static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
csr_writel(pcie, 1 << WIN_ENABLE_SHIFT | type << WIN_TYPE_SHIFT |
lower_32_bits(size64), PAB_AXI_AMAP_CTRL(win_num));

- write_paged_register(pcie, upper_32_bits(size64),
- PAB_EXT_AXI_AMAP_SIZE(win_num));
+ csr_writel(pcie, upper_32_bits(size64), PAB_EXT_AXI_AMAP_SIZE(win_num));

/*
* program AXI window base with appropriate value in
--
1.7.1
\
 
 \ /
  Last update: 2019-07-05 12:10    [W:0.120 / U:3.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site